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Thuy B, Gale A, Numberger-Thuy L. Brittle stars looking like starfish: the first fossil record of the Astrophiuridae and a remarkable case of convergent evolution. PeerJ 2019; 7:e8008. [PMID: 31741791 PMCID: PMC6858817 DOI: 10.7717/peerj.8008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 10/07/2019] [Indexed: 11/20/2022] Open
Abstract
The genus Astrophiura, which ranks among the most extraordinary of modern brittle stars, is the type genus of the recently resurrected family Astrophiuridae within the order Ophiurida. On account of its absurdly enlarged and strongly modified lateral arm plates, Astrophiura bears a closer resemblance to a pentagonal starfish than to a typical ophiuroid. Although molecular evidence suggests an ancient origin of the Astrophiuridae, dating back at least to the Early Jurassic, not a single fossil astrophiurid has been reported so far. Here, we describe dissociated lateral arm plates from the Campanian of Cringleford near Norwich, UK, and the Maastrichtian of Rügen, Germany (both Upper Cretaceous) with unambiguous astrophiurid affinities and assign these to a new species, Astrophiura markbeneckei. This represents the first fossil record of the family. In addition, the Rügen material included lateral arm plates that superficially resemble those of A. markbeneckei sp. nov. but differ in having spine articulations that are typical of the ophionereidoid family Amphilimnidae. We assign these plates to a new genus and species, Astrosombra rammsteinensis, an extinct amphilimnid with morphological modifications similar to those of Astrophiura, and thus representing a remarkable case of parallel evolution amongst brittle stars looking like starfish.
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Affiliation(s)
- Ben Thuy
- Department of Palaeontology, Natural History Museum Luxembourg, Luxembourg City, Luxembourg
| | - Andy Gale
- School of Earth & Environmental Sciences, University of Portsmouth, Portsmouth, UK
| | - Lea Numberger-Thuy
- Department of Palaeontology, Natural History Museum Luxembourg, Luxembourg City, Luxembourg
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Christodoulou M, O'Hara TD, Hugall AF, Arbizu PM. Dark Ophiuroid Biodiversity in a Prospective Abyssal Mine Field. Curr Biol 2019; 29:3909-3912.e3. [PMID: 31630951 DOI: 10.1016/j.cub.2019.09.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 07/04/2019] [Accepted: 09/05/2019] [Indexed: 01/30/2023]
Abstract
The seafloor contains valuable mineral resources, including polymetallic (or manganese) nodules that form on offshore abyssal plains. The largest and most commercially attractive deposits are located in the Clarion Clipperton Fracture Zone (CCZ), in the eastern Pacific Ocean (EP) between Hawaii and Mexico, where testing of a mineral collection system is set to start soon [1]. The requirement to establish pre-mining environmental management plans has prompted numerous recent biodiversity and DNA barcoding surveys across these remote regions. Here we map DNA sequences from sampled ophiuroids (brittle stars, including post-larvae) of the CCZ and Peru Basin onto a substantial tree of life to show unprecedented levels of abyssal ophiuroid phylogenetic diversity including at least three ancient (>70 Ma), previously unknown clades. While substantial dark (unobserved) biodiversity has been reported from various microbial meta-barcoding projects [2, 3], our data show that we have considerably under-estimated the biodiversity of even the most conspicuous mega-faunal invertebrates [4] of the EP abyssal plain.
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Affiliation(s)
- Magdalini Christodoulou
- German Centre for Marine Biodiversity Research, Senckenberg am Meer, Südstrand 44, 26382 Wilhelmshaven, Germany
| | - Timothy D O'Hara
- Museums Victoria, Sciences Department, 11 Nicholson Street, Carlton 3054, VIC, Australia.
| | - Andrew F Hugall
- Museums Victoria, Sciences Department, 11 Nicholson Street, Carlton 3054, VIC, Australia
| | - Pedro Martinez Arbizu
- German Centre for Marine Biodiversity Research, Senckenberg am Meer, Südstrand 44, 26382 Wilhelmshaven, Germany
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Seknazi E, Kozachkevich S, Polishchuk I, Bianco Stein N, Villanova J, Suuronen JP, Dejoie C, Zaslansky P, Katsman A, Pokroy B. From spinodal decomposition to alternating layered structure within single crystals of biogenic magnesium calcite. Nat Commun 2019; 10:4559. [PMID: 31594921 PMCID: PMC6783414 DOI: 10.1038/s41467-019-12168-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 08/27/2019] [Indexed: 11/09/2022] Open
Abstract
As organisms can form crystals only under ambient conditions, they demonstrate fascinating strategies to overcome this limitation. Recently, we reported a previously unknown biostrategy for toughening brittle calcite crystals, using coherently incorporated Mg-rich nanoprecipitates arranged in a layered manner in the lenses of a brittle star, Ophiocoma wendtii. Here we propose the mechanisms of formation of this functional hierarchical structure under conditions of ambient temperature and limited solid diffusion. We propose that formation proceeds via a spinodal decomposition of a liquid or gel-like magnesium amorphous calcium carbonate (Mg-ACC) precursor into Mg-rich nanoparticles and a Mg-depleted amorphous matrix. In a second step, crystallization of the decomposed amorphous precursor leads to the formation of high-Mg particle-rich layers. The model is supported by our experimental results in synthetic systems. These insights have significant implications for fundamental understanding of the role of Mg-ACC material transformation during crystallization and its subsequent stability.
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Affiliation(s)
- Eva Seknazi
- Department of Materials Science and Engineering and the Russel Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, 32000, Haifa, Israel
| | - Stas Kozachkevich
- Department of Materials Science and Engineering and the Russel Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, 32000, Haifa, Israel
| | - Iryna Polishchuk
- Department of Materials Science and Engineering and the Russel Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, 32000, Haifa, Israel
| | - Nuphar Bianco Stein
- Department of Materials Science and Engineering and the Russel Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, 32000, Haifa, Israel
| | - Julie Villanova
- ESRF-The European Synchrotron Radiation Facility, CS 40220, 38043, Grenoble Cedex 9, France
| | - Jussi-Petteri Suuronen
- ESRF-The European Synchrotron Radiation Facility, CS 40220, 38043, Grenoble Cedex 9, France
| | - Catherine Dejoie
- ESRF-The European Synchrotron Radiation Facility, CS 40220, 38043, Grenoble Cedex 9, France
| | - Paul Zaslansky
- Department for Restorative and Preventive Dentistry, Centrum für Zahn-, Mund- und Kieferheilkunde, Charité-Universitätsmedizin Berlin, 14197, Berlin, Germany
| | - Alex Katsman
- Department of Materials Science and Engineering and the Russel Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, 32000, Haifa, Israel
| | - Boaz Pokroy
- Department of Materials Science and Engineering and the Russel Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, 32000, Haifa, Israel.
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Madeira P, Kroh A, Cordeiro R, DE Frias Martins AM, Ávila SP. The Echinoderm Fauna of the Azores (NE Atlantic Ocean). Zootaxa 2019; 4639:zootaxa.4639.1.1. [PMID: 31712455 DOI: 10.11646/zootaxa.4639.1.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Indexed: 11/04/2022]
Abstract
In more than 150 years of research in the waters surrounding the Azores, several publications on the fauna of echinoderms of the archipelago have been produced, in the form of papers, notes, reports, reviews, and monographs. This work attempts to summarize the present knowledge on this marine group in the Azorean exclusive economic zone (i.e., waters within 200 nautical miles of the archipelago's shores). A short review of the history of the species' taxonomy is given, with key references, geographical distribution, ecology, additional notes and, when possible, figures. We herein report 172 species of echinoderms (6 crinoids, 55 ophiuroids, 45 asteroids, 36 holothurians, and 30 echinoids) from the Azores Archipelago, most of them inhabiting deep waters (>200 m). Only 29 shallow-water species were recorded locally (≤50 m depth). In general, the echinoderm species present in the Azores are characterized by a wide geographical distribution in the Atlantic Ocean. Only nine taxa (all deep-water species, >840 m) appear to be restricted to the Azorean waters. Overall, the knowledge of the echinoderm fauna of the Azores is out-dated, with many species last collected in the archipelago over 100 years ago. A recent interest in the Azorean Mid-Atlantic waters has brought oceanographic cruises back to the archipelago, thus providing new opportunities for the renewal of 150 years of echinoderm studies in the area.
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Affiliation(s)
- Patrícia Madeira
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Pólo dos Açores, Portugal Departamento de Biologia, Faculdade de Ciências e Tecnologia, Universidade dos Açores, Apartado 1422, 9501-801 Ponta Delgada, Açores, Portugal.
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Okanishi M, Fujita T. Description of a New Subfamily, Astrocloninae (Ophiuroidea: Euryalida: Gorgonocephalidae), Based on Molecular Phylogeny and Morphological Observations. Zoolog Sci 2019; 35:179-187. [PMID: 29623787 DOI: 10.2108/zs170090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Previous phylogenetic studies of the family Gorgonocephalidae (brittle stars and basket stars) have identified three subfamilies, Astrotominae, Astrothamninae, and Gorgonocephalinae. The genus Astroclon was tentatively assigned to the subfamily Astrothamninae in previous studies, but its morphology is enigmatic and molecular data of the genus was insufficient. Therefore, the systematic position of Astroclon required confirmation to reconstruct the accurate systematics of the Euryalida. In the present study, we sought to clarify the subfamilial classification in the family Gorgonocephalidae (Echinodermata: Ophiuroidea: Euryalida). We revisited molecular phylogenetics of the Gorgonocephalidae including Astroclon and the major taxa in the family. The molecular analysis supported monophyly of the two species of Astroclon and its clear separation from Astrothamninae. The two Astroclon species were also distinguished from the other two subfamilies, Astrotominae and Gorgonocephalinae. Astroclon and three other subfamilies were divided in the basal position of the Gorgonocephalidae, and were assigned to subfamilies. A new subfamily, Astrocloninae was monotypically established for Astroclon in addition to the previous three subfamilies. Morphology of the first ventral arm plates and tentacle pores also supported distinctiveness of the new subfamily.
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Affiliation(s)
- Masanori Okanishi
- 1 Misaki Marine Biological Station, Graduate School of Science, The University of Tokyo, 1024 Koajiro, Misaki, Miura, Kanagawa 238-0225, Japan
| | - Toshihiko Fujita
- 2 National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba, Ibaraki 305-0005, Japan
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Bribiesca-Contreras G, Pineda-Enríquez T, Márquez-Borrás F, Solís-Marín FA, Verbruggen H, Hugall AF, O'Hara TD. Dark offshoot: Phylogenomic data sheds light on the evolutionary history of a new species of cave brittle star. Mol Phylogenet Evol 2019; 136:151-163. [PMID: 30981811 DOI: 10.1016/j.ympev.2019.04.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Revised: 02/28/2019] [Accepted: 04/10/2019] [Indexed: 11/28/2022]
Abstract
Caves are a useful system for testing evolutionary and biogeographic hypotheses, as they are isolated, and their environmental conditions have resulted in adaptive selection across different taxa. Although in recent years many more cave species have been discovered, cave-dwelling members of the class Ophiuroidea (brittle stars) remain scarce. Out of the more than two thousand species of brittle stars described to date, only three are regarded as true cave-dwellers. These occurrences represent rare colonising events, compared to other groups that are known to have successfully diversified in these systems. A third species from an anchihaline cave system in the Yucatan Peninsula, Mexico, has been previously identified from cytochrome oxidase I (COI) barcodes. In this study, we reassess the species boundaries of this putative cave species using a phylogenomic dataset (20 specimens in 13 species, 100 exons, 18.7 kbp). We perform species delimitation analyses using robust full-coalescent methods for discovery and validation of hypotheses on species boundaries, as well as infer its phylogenetic relationships with species distributed in adjacent marine regions, in order to investigate the origin of this cave-adapted species. We assess which hypotheses on the origin of subterranean taxa can be applied to this species by taking into account its placement within the genus Ophionereis and its demographic history. We provide a detailed description of Ophionereis commutabilis n. sp., and evaluate its morphological characters in the light of its successful adaptation to life in caves.
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Affiliation(s)
- Guadalupe Bribiesca-Contreras
- Museum Victoria, GPO Box 666, Melbourne 3001, Australia; School of Biosciences, University of Melbourne, Victoria 3010, Australia.
| | - Tania Pineda-Enríquez
- Department of Biology, Division of Invertebrate Zoology, Florida Museum of Natural History, University of Florida, Gainesville, FL, USA; Natural History Museum of Los Angeles County, 900 Exposition Blvd, Los Angeles, CA 90007, USA
| | - Francisco Márquez-Borrás
- Laboratorio de Sistemática y Ecología de Equinodermos, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Circuito Universitario s/n, Ciudad de México CP 04510, Mexico; Posgrado en Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Circuito Universitario s/n, Ciudad de México CP 04510, Mexico
| | - Francisco A Solís-Marín
- Laboratorio de Sistemática y Ecología de Equinodermos, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Circuito Universitario s/n, Ciudad de México CP 04510, Mexico
| | - Heroen Verbruggen
- School of Biosciences, University of Melbourne, Victoria 3010, Australia
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57
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Biological and Physical Effects of Brine Discharge from the Carlsbad Desalination Plant and Implications for Future Desalination Plant Constructions. WATER 2019. [DOI: 10.3390/w11020208] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Seawater reverse osmosis (SWRO) desalination is increasingly used as a technology for addressing shortages of freshwater supply and desalination plants are in operation or being planned world-wide and specifically in California, USA. However, the effects of continuous discharge of high-salinity brine into coastal environments are ill-constrained and in California are an issue of public debate. We collected in situ measurements of water chemistry and biological indicators in coastal waters (up to ~2 km from shore) before and after the newly constructed Carlsbad Desalination Plant (Carlsbad, CA, USA) began operations. A bottom water salinity anomaly indicates that the spatial footprint of the brine discharge plume extended about 600 m offshore with salinity up to 2.7 units above ambient (33.2). This exceeds the maximum salinity permitted for this location based on the California Ocean Plan (2015 Amendment to Water Quality Control Plan). However, no significant changes in the assessed biological indicators (benthic macrofauna, BOPA-index, brittle-star survival and growth) were observed at the discharge site. A model of mean ocean wave potential was used as an indicator of coastal mixing at Carlsbad Beach and at other locations in southern and central CA where desalination facilities are proposed. Our results indicated that to minimize environmental impacts discharge should target waters where a long history of anthropogenic activity has already compromised the natural setting. To ensure adequate mixing of the discharge brine desalination plants should be constructed at high-energy sites with sandy substrates, and discharge through diffusor systems.
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58
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Alitto RADS, Amaral ACZ, de Oliveira LD, Serrano H, Seger KR, Guilherme PDB, Domenico MD, Christensen AB, Lourenço LB, Tavares M, Borges M. Atlantic West Ophiothrix spp. in the scope of integrative taxonomy: Confirming the existence of Ophiothrix trindadensis Tommasi, 1970. PLoS One 2019; 14:e0210331. [PMID: 30673722 PMCID: PMC6343879 DOI: 10.1371/journal.pone.0210331] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 12/20/2018] [Indexed: 11/20/2022] Open
Abstract
We re-describe and confirm the validity of Ophiothrix trindadensis Tommasi, 1970 (Echinodermata: Ophiuroidea). This is a native species from Brazil, however it lacked a type series deposited in scientific collections. The recognition of O. trindadensis was made possible using integrative taxonomy applied to many specimens from the type locality (Trindade Island) as well as from different locations along the Brazilian coast (Araçá Bay and Estuarine Complex of Paranaguá). Initially, 835 specimens were studied and divided into four candidate species (CS) inferred from external morphological characters. Afterwards, the CSs were compared using integrative taxonomy based on external morphology, arm microstructures morphology (arm ossicle), morphometry, and molecular studies (fragments of the mitochondrial genes 16S and COI). Analyses indicated CS1 and CS2 as O. trindadensis, and CS3 as O. angulata, both valid species. CS4 remains O. cf. angulata as more data, including their ecology and physiology, are needed to be definitively clarified. Our integrative investigation using specimens from the type locality overcame the lack of type specimens and increased the reliable identification of O. trindadensis and O. angulata.
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Affiliation(s)
- Renata Aparecida dos Santos Alitto
- Departamento de Biologia Animal, Universidade Estadual de Campinas, Campinas, São Paulo, Brasil
- Museu de Zoologia “Adão José Cardoso”, Universidade Estadual de Campinas, Campinas, São Paulo, Brasil
| | | | - Letícia Dias de Oliveira
- Departamento de Biologia Animal, Universidade Estadual de Campinas, Campinas, São Paulo, Brasil
- Museu de Zoologia “Adão José Cardoso”, Universidade Estadual de Campinas, Campinas, São Paulo, Brasil
| | - Helena Serrano
- Departamento de Biologia Animal, Universidade Estadual de Campinas, Campinas, São Paulo, Brasil
- Museu de Zoologia “Adão José Cardoso”, Universidade Estadual de Campinas, Campinas, São Paulo, Brasil
| | - Karin Regina Seger
- Departamento de Biologia Animal, Universidade Estadual de Campinas, Campinas, São Paulo, Brasil
- Departamento de Biologia Celular, Universidade Estadual de Campinas, Campinas, São Paulo, Brasil
| | | | - Maikon Di Domenico
- Centro de Estudos do Mar, Universidade Federal do Paraná, Pontal do Paraná, Paraná, Brasil
| | | | - Luciana Bolsoni Lourenço
- Departamento de Biologia Celular, Universidade Estadual de Campinas, Campinas, São Paulo, Brasil
| | - Marcos Tavares
- Museu de Zoologia da Universidade de São Paulo, São Paulo, Brasil
| | - Michela Borges
- Departamento de Biologia Animal, Universidade Estadual de Campinas, Campinas, São Paulo, Brasil
- Museu de Zoologia “Adão José Cardoso”, Universidade Estadual de Campinas, Campinas, São Paulo, Brasil
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O'Hara TD, Hugall AF, Woolley SNC, Bribiesca-Contreras G, Bax NJ. Contrasting processes drive ophiuroid phylodiversity across shallow and deep seafloors. Nature 2019; 565:636-639. [PMID: 30675065 DOI: 10.1038/s41586-019-0886-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 12/14/2018] [Indexed: 11/09/2022]
Abstract
Our knowledge of the distribution and evolution of deep-sea life is limited, impeding our ability to identify priority areas for conservation1. Here we analyse large integrated phylogenomic and distributional datasets of seafloor fauna from the sea surface to the abyss and from equator to pole of the Southern Hemisphere for an entire class of invertebrates (Ophiuroidea). We find that latitudinal diversity gradients are assembled through contrasting evolutionary processes for shallow (0-200 m) and deep (>200 m) seas. The shallow-water tropical-temperate realm broadly reflects a tropical diversification-driven process that shows exchange of lineages in both directions. Diversification rates are reversed for the realm that contains the deep sea and Antarctica; the diversification rates are highest at polar and lowest at tropical latitudes, and net exchange occurs from high to low latitudes. The tropical upper bathyal (200-700 m deep), with its rich ancient phylodiversity, is characterized by relatively low diversification and moderate immigration rates. Conversely, the young, specialized Antarctic fauna is inferred to be rebounding from regional extinctions that are associated with the rapid cooling of polar waters during the mid-Cenozoic era.
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Affiliation(s)
| | | | - Skipton N C Woolley
- Museums Victoria, Melbourne, Victoria, Australia.,CSIRO Oceans and Atmosphere, Hobart, Tasmania, Australia
| | - Guadalupe Bribiesca-Contreras
- Museums Victoria, Melbourne, Victoria, Australia.,Biosciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Nicholas J Bax
- CSIRO Oceans and Atmosphere, Hobart, Tasmania, Australia.,Institute for Marine and Antarctic Science, University of Tasmania, Hobart, Tasmania, Australia
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60
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Thuy B, Landman NH, Larson NL, Numberger-Thuy LD. Brittle-star mass occurrence on a Late Cretaceous methane seep from South Dakota, USA. Sci Rep 2018; 8:9617. [PMID: 29941907 PMCID: PMC6018167 DOI: 10.1038/s41598-018-27326-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 05/29/2018] [Indexed: 11/09/2022] Open
Abstract
Articulated brittle stars are rare fossils because the skeleton rapidly disintegrates after death and only fossilises intact under special conditions. Here, we describe an extraordinary mass occurrence of the ophiacanthid ophiuroid Brezinacantha tolis gen. et sp. nov., preserved as articulated skeletons from an upper Campanian (Late Cretaceous) methane seep of South Dakota. It is uniquely the first fossil case of a seep-associated ophiuroid. The articulated skeletons overlie centimeter-thick accumulations of dissociated skeletal parts, suggesting lifetime densities of approximately 1000 individuals per m2, persisting at that particular location for several generations. The ophiuroid skeletons on top of the occurrence were preserved intact most probably because of increased methane seepage, killing the individuals and inducing rapid cementation, rather than due to storm-induced burial or slumping. The mass occurrence described herein is an unambiguous case of an autochthonous, dense ophiuroid community that persisted at a particular spot for some time. Thus, it represents a true fossil equivalent of a recent ophiuroid dense bed, unlike other cases that were used in the past to substantiate the claim of a mid-Mesozoic predation-induced decline of ophiuroid dense beds.
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61
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Clark EG, Hutchinson JR, Darroch SAF, Mongiardino Koch N, Brady TR, Smith SA, Briggs DEG. Integrating morphology and in vivo skeletal mobility with digital models to infer function in brittle star arms. J Anat 2018; 233:696-714. [PMID: 30353539 PMCID: PMC6231174 DOI: 10.1111/joa.12887] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2018] [Indexed: 12/15/2022] Open
Abstract
Brittle stars (Phylum Echinodermata, Class Ophiuroidea) have evolved rapid locomotion employing muscle and skeletal elements within their (usually) five arms to apply forces in a manner analogous to that of vertebrates. Inferring the inner workings of the arm has been difficult as the skeleton is internal and many of the ossicles are sub-millimeter in size. Advances in 3D visualization and technology have made the study of movement in ophiuroids possible. We developed six virtual 3D skeletal models to demonstrate the potential range of motion of the main arm ossicles, known as vertebrae, and six virtual 3D skeletal models of non-vertebral ossicles. These models revealed the joint center and relative position of the arm ossicles during near-maximal range of motion. The models also provide a platform for the comparative evaluation of functional capabilities between disparate ophiuroid arm morphologies. We made observations on specimens of Ophioderma brevispina and Ophiothrix angulata. As these two taxa exemplify two major morphological categories of ophiuroid vertebrae, they provide a basis for an initial assessment of the functional consequences of these disparate vertebral morphologies. These models suggest potential differences in the structure of the intervertebral articulations in these two species, implying disparities in arm flexion mechanics. We also evaluated the differences in the range of motion between segments in the proximal and distal halves of the arm length in a specimen of O. brevispina, and found that the morphology of vertebrae in the distal portion of the arm allows for higher mobility than in the proximal portion. Our models of non-vertebral ossicles show that they rotate further in the direction of movement than the vertebrae themselves in order to accommodate arm flexion. These findings raise doubts over previous hypotheses regarding the functional consequences of ophiuroid arm disparity. Our study demonstrates the value of integrating experimental data and visualization of articulated structures when making functional interpretations instead of relying on observations of vertebral or segmental morphology alone. This methodological framework can be applied to other ophiuroid taxa to enable comparative functional analyses. It will also facilitate biomechanical analyses of other invertebrate groups to illuminate how appendage or locomotor function evolved.
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Affiliation(s)
| | - John R. Hutchinson
- Structure and Motion LaboratoryDepartment of Comparative Biomedical SciencesThe Royal Veterinary CollegeHertfordshireUK
| | - Simon A. F. Darroch
- Department of Earth and Environmental ScienceVanderbilt UniversityNashvilleTNUSA
| | | | - Travis R. Brady
- Department of Biomedical EngineeringYale UniversityNew HavenCTUSA
| | - Sloane A. Smith
- Department of Biomedical EngineeringYale UniversityNew HavenCTUSA
| | - Derek E. G. Briggs
- Department of Geology and GeophysicsYale UniversityNew HavenCTUSA
- Yale Peabody Museum of Natural HistoryYale UniversityNew HavenCTUSA
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62
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Galaska MP, Li Y, Kocot KM, Mahon AR, Halanych KM. Conservation of mitochondrial genome arrangements in brittle stars (Echinodermata, Ophiuroidea). Mol Phylogenet Evol 2018; 130:115-120. [PMID: 30316947 DOI: 10.1016/j.ympev.2018.10.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 09/25/2018] [Accepted: 10/01/2018] [Indexed: 11/18/2022]
Abstract
Brittle stars are conspicuous members of benthic ecosystems, fill many ecological niches and are the most speciose of all classes of echinoderms. With high levels of biodiversity, elucidating the evolutionary history of this group is important. Understanding of higher-level relationships within Ophiuroidea has been aided by multilocus nuclear data and DNA barcoding. However, the degree of consistency between mitochondrial and nuclear data within ophiuroids remains unclear and deserves further assessment. In this study, 17 mitochondrial genomes spanning the taxonomic breadth of Ophiuroidea were utilized to explore evolutionary relationships through maximum likelihood analyses, Bayesian inference and comparative assessment of gene order. Our phylogenetic analyses, based on both nucleotide and amino acid residues, support recent findings based on multilocus nuclear data and morphology, in that the brittle star clades Ophintegrida and Euryophiurida were recovered as monophyletic with the latter comprising Euyalida, Ophiuridae and Ophiopyrgidae. Only three different arrangements of the 13 protein coding and 2 ribosomal RNA genes were observed. As expected, tRNA genes were more likely to have undergone rearrangement but the order of all 37 genes was found to be conserved in all sampled Euryalida and Ophiuridae. Both Euryalida and the clade comprised of Ophiuridae and Ophiopyrgidae, each had their own conserved rearrangement of protein coding genes and ribosomal genes, after divergence from their last common ancestor. Euryalida has a rearrangement of the two ribosomal RNA genes, rrnS and rrnL, in contrast to Ophiuridae and Ophiopyrgidae, which had an inversion of the genes nad1, nad2, and cob relative to Ophintegrida. Further, our data support the gene order found in all sampled Euryalida as the most likely ancestral order for all Ophiuroidea.
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Affiliation(s)
- Matthew P Galaska
- Department of Biological Sciences, Auburn University, Molette Biology Laboratory for Environmental and Climate Change Studies, 101 Rouse Life Science Building, Auburn, AL 36849, USA; Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015, USA.
| | - Yuanning Li
- Department of Biological Sciences, Auburn University, Molette Biology Laboratory for Environmental and Climate Change Studies, 101 Rouse Life Science Building, Auburn, AL 36849, USA
| | - Kevin M Kocot
- Department of Biological Sciences and Alabama Museum of Natural History, University of Alabama, Tuscaloosa, AL 35487, USA
| | - Andrew R Mahon
- Department of Biology, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Kenneth M Halanych
- Department of Biological Sciences, Auburn University, Molette Biology Laboratory for Environmental and Climate Change Studies, 101 Rouse Life Science Building, Auburn, AL 36849, USA.
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63
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Wilkie IC, Brogger MI. The peristomial plates of ophiuroids (Echinodermata: Ophiuroidea) highlight an incongruence between morphology and proposed phylogenies. PLoS One 2018; 13:e0202046. [PMID: 30092013 PMCID: PMC6084971 DOI: 10.1371/journal.pone.0202046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 07/26/2018] [Indexed: 11/19/2022] Open
Abstract
The peristomial plates are skeletal components of the interbrachial frame (or mouth frame), which is located below the true mouth of ophiuroids. Whilst the peristomial plates were extensively described and used as diagnostic characters by some early workers, for the past 100 years they have been largely neglected as a taxonomic resource. In this investigation the peristomial plates of 48 species representing 21 families were examined directly, and information on a further 61 species, including representatives of another eight families, was obtained from the published literature. Observations were made with regard to fragmentation state, relative size and orientation of the peristomial plates. Although fragmentation state showed little consistency at any taxonomic level, relative size and orientation segregated a group of families comprising species with relatively small, inclined peristomial plates, viz. Ophiotrichidae, Ophiopholidae, Ophiactidae, Amphiuridae and Ophiocomidae, together with a single hemieuryalid species-Ophioplocus januarii. The distribution of peristomial plate traits was strongly correlated with that of several other character states pertaining to the interbrachial frame. This supported the proposition that two major types of interbrachial frame are present in ophiuroids (designated 'A' and 'B'). Current phylogenies inferred from both morphological and molecular data imply that type B is derived and has evolved independently at least twice in the orders Amphilepidida and Ophiacanthida. This represents a remarkable example of evolutionary convergence. An analysis of the distribution of all interbrachial frame character states suggested that within the Amphilepidida paedomorphosis was probably responsible for the complete reversion of the interbrachial frame to the ancestral type A condition in two families (Ophiothamnidae and Amphilepididae) of suborder Gnathophiurina and possibly responsible for varying degrees of trait reversal in the four families of suborder Ophionereidina. Such paedomorphic events may have been associated with a secondary return to the deep-sea from shallow-sea environments.
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Affiliation(s)
- Iain C. Wilkie
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, Scotland, United Kingdom
- * E-mail:
| | - Martín I. Brogger
- Laboratorio de Reproducción y Biología Integrativa de Invertebrados Marinos, IBIOMAR-CONICET, Blvd. Almirante Brown, Puerto Madryn, Argentina
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64
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Unravelling the origin of the basket stars and their allies (Echinodermata, Ophiuroidea, Euryalida). Sci Rep 2018; 8:8493. [PMID: 29855566 PMCID: PMC5981468 DOI: 10.1038/s41598-018-26877-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 05/20/2018] [Indexed: 11/16/2022] Open
Abstract
Euryalids, which include the spectacular basket stars, form a morphologically aberrant group of brittle stars. Surprisingly, the most recent molecular work found them to be sister to ophiurid brittle stars, thus challenging the traditional dichotomy between euryalids and non-euryalids, and leaving an enormous ghost lineage of more than 100 million years between the oldest unambiguous euryalid fossils and their predicted divergence from ophiurids during the Triassic. Here we examine both previously known and newly collected fossils to explore the evolutionary history of euryalids. A morphology-based phylogenetic estimate confirms the Triassic Aspiduriella as a basal member of the euryalid clade that superficially resembles members of the living ophiurid sister clades. Furthermore, we use lateral arm plates and vertebrae to identify two new Jurassic ophiuroids, Melusinaster alissawhitegluzae and Melusinaster arcusinimicus, as early euryalids that are morphologically intermediate between Aspiduriella and extant euryalids. Our phylogenetic analysis is the first to combine data from completely preserved skeletons and from microfossils in order to bridge morphological and stratigraphical gaps between the sampled taxa. It fills a major gap in the fossil record of euryalids and sets a robust phylogenetic framework to understand the morphological transition from ophiurid-like ancestors to the typical modern euryalids better.
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65
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Zandawala M, Moghul I, Yañez Guerra LA, Delroisse J, Abylkassimova N, Hugall AF, O'Hara TD, Elphick MR. Discovery of novel representatives of bilaterian neuropeptide families and reconstruction of neuropeptide precursor evolution in ophiuroid echinoderms. Open Biol 2018; 7:rsob.170129. [PMID: 28878039 PMCID: PMC5627052 DOI: 10.1098/rsob.170129] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 07/27/2017] [Indexed: 11/12/2022] Open
Abstract
Neuropeptides are a diverse class of intercellular signalling molecules that mediate neuronal regulation of many physiological and behavioural processes. Recent advances in genome/transcriptome sequencing are enabling identification of neuropeptide precursor proteins in species from a growing variety of animal taxa, providing new insights into the evolution of neuropeptide signalling. Here, detailed analysis of transcriptome sequence data from three brittle star species, Ophionotus victoriae, Amphiura filiformis and Ophiopsila aranea, has enabled the first comprehensive identification of neuropeptide precursors in the class Ophiuroidea of the phylum Echinodermata. Representatives of over 30 bilaterian neuropeptide precursor families were identified, some of which occur as paralogues. Furthermore, homologues of endothelin/CCHamide, eclosion hormone, neuropeptide-F/Y and nucleobinin/nesfatin were discovered here in a deuterostome/echinoderm for the first time. The majority of ophiuroid neuropeptide precursors contain a single copy of a neuropeptide, but several precursors comprise multiple copies of identical or non-identical, but structurally related, neuropeptides. Here, we performed an unprecedented investigation of the evolution of neuropeptide copy number over a period of approximately 270 Myr by analysing sequence data from over 50 ophiuroid species, with reference to a robust phylogeny. Our analysis indicates that the composition of neuropeptide ‘cocktails’ is functionally important, but with plasticity over long evolutionary time scales.
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Affiliation(s)
- Meet Zandawala
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Ismail Moghul
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Luis Alfonso Yañez Guerra
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Jérôme Delroisse
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Nikara Abylkassimova
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Andrew F Hugall
- Museums Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia
| | - Timothy D O'Hara
- Museums Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia
| | - Maurice R Elphick
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
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66
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A new cryptic species of Asteronyx Müller and Troschel, 1842 (Echinodermata: Ophiuroidea), based on molecular phylogeny and morphology, from off Pacific Coast of Japan. ZOOL ANZ 2018. [DOI: 10.1016/j.jcz.2018.03.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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67
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Okanishi M, Fujita Y. A new species ofOphioconis(Echinodermata: Ophiuroidea) from Ryukyu Islands, southwestern Japan. P BIOL SOC WASH 2018. [DOI: 10.2988/18-00001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Masanori Okanishi
- (MO) Misaki Marine Biological Laboratory, Department of Science, The University of Tokyo, 1014 Koajiro, Miura, Kanagawa, 238-0225 Japan,
| | - Yoshihisa Fujita
- (YF) Okinawa Prefectural University of Arts, 1-4 Shuri-Tounokura, Naha, Okinawa, 903-8602 Japan,
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68
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Saniewski M, Borszcz T. 90Sr and 137Cs in Arctic echinoderms. MARINE POLLUTION BULLETIN 2017; 124:563-568. [PMID: 28781189 DOI: 10.1016/j.marpolbul.2017.07.068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Revised: 07/15/2017] [Accepted: 07/30/2017] [Indexed: 06/07/2023]
Abstract
Radionuclides in the Arctic echinoderms have seldom been studied despite their considerable environmental importance. This manuscript covers the results of 90Sr and 137Cs measurements in common echinoderm taxa collected from the Svalbard Bank in the Barents Sea and from two High-Arctic fjords (Isfjorden and Magdalenefjorden). We focused on the echinoid, Strongylocentrotus droebachiensis, the asteroid, Henricia sanguinolenta, and the ophiuroid, Ophiopolis aculeata. For all echinoderms, the analysis revealed a negative correlation between 90Sr activity and the mass. Thus, we concluded that metals are accumulated faster at a young age when the growth is most rapid. The highest average activities of 137Cs followed the order O. aculeata>H. sanguinolenta>S. droebachiensis. This suggests that bioaccumulation was highly taxon-dependent and could reflect differences in the isotope exposures associated with the diet of echinoderms. The study provides a baseline for understanding radionuclide processes in the High-Arctic benthic echinoderm communities.
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Affiliation(s)
- Michał Saniewski
- Institute of Meteorology and Water Management, National Research Institute, Maritime Branch, Waszyngtona 42, 81-342 Gdynia, Poland.
| | - Tomasz Borszcz
- Institute of Oceanology, Polish Academy of Sciences, Marine Ecology Department, Powstańców Warszawy 55, 81-712 Sopot, Poland.
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69
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High-throughput targeted screening in triple-negative breast cancer cells identifies Wnt-inhibiting activities in Pacific brittle stars. Sci Rep 2017; 7:11964. [PMID: 28931883 PMCID: PMC5607299 DOI: 10.1038/s41598-017-12232-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 09/06/2017] [Indexed: 02/06/2023] Open
Abstract
Pro-proliferative oncogenic signaling is one of the hallmarks of cancer. Specific targeting of such signaling pathways is one of the main approaches to modern anti-cancer drug discovery, as opposed to more traditional search for general cytotoxic agents. Natural products, especially from marine sources, represent a largely untapped source of chemical diversity, which so far have mostly been screened for cytotoxicity. Here we present a pioneering pipeline of high-throughput screening of marine-based activities targeted against the Wnt signaling pathway, which is one of the key factors in oncogenic transformation, growth and metastasis in different cancers, including the devastating triple-negative breast cancer (TNBC) currently lacking any targeted therapies. This pipeline consisted of collection and characterization of numerous invertebrates during the SokhoBio expedition to the Kuril Basin in North Pacific, preparation of extracts from these specimen, and their screening in dedicated assays monitoring Wnt signaling in TNBC cells. This approach yielded a number of promising hits, including highly specific anti-Wnt activities targeting multiple levels within the Wnt pathway from Ophiura irrorata and other Pacific brittle stars.
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70
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Bribiesca-Contreras G, Verbruggen H, Hugall AF, O'Hara TD. The importance of offshore origination revealed through ophiuroid phylogenomics. Proc Biol Sci 2017; 284:20170160. [PMID: 28679721 PMCID: PMC5524485 DOI: 10.1098/rspb.2017.0160] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 05/31/2017] [Indexed: 11/12/2022] Open
Abstract
Our knowledge of macro-evolutionary processes in the deep sea is poor, leading to much speculation about whether the deep sea is a source or sink of evolutionary adaptation. Here, we use a phylogenetic approach, on large molecular (688 species, 275 kbp) and distributional datasets (104 513 records) across an entire class of marine invertebrates (Ophiuroidea), to infer rates of bathymetric range shift over time between shallow and deep water biomes. Biome conservation is evident through the phylogeny, with the majority of species in most clades distributed within the same bathome. Despite this, bathymetric shifts have occurred. We inferred from ancestral reconstructions that eurybathic or intermediate distributions across both biomes were a transitional state and direct changes between shallow and deep sea did not occur. The macro-evolutionary pattern of bathome shift appeared to reflect micro-evolutionary processes of bathymetric speciation. Results suggest that most of the oldest clades have a deep-sea origin, but multiple colonization events indicate that the evolution of this group conforms neither to a simple onshore-offshore hypothesis, nor the opposite pattern. Both shallow and deep bathomes have played an important role in generating the current diversity of this major benthic class.
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Affiliation(s)
- Guadalupe Bribiesca-Contreras
- Museums Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia
- School of Biosciences, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Heroen Verbruggen
- School of Biosciences, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Andrew F Hugall
- Museums Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia
| | - Timothy D O'Hara
- Museums Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia
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71
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Galaska MP, Sands CJ, Santos SR, Mahon AR, Halanych KM. Crossing the Divide: Admixture Across the Antarctic Polar Front Revealed by the Brittle Star Astrotoma agassizii. THE BIOLOGICAL BULLETIN 2017; 232:198-211. [PMID: 28898598 DOI: 10.1086/693460] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The Antarctic Polar Front (APF) is one of the most well-defined and persistent oceanographic features on the planet and serves as a barrier to dispersal between the Southern Ocean and lower latitudes. High levels of endemism in the Southern Ocean have been attributed to this barrier, whereas the accompanying Antarctic Circumpolar Current (ACC) likely promotes west-to-east dispersal. Previous phylogeographic work on the brittle star Astrotoma agassizii Lyman, 1875 based on mitochondrial genes suggested isolation across the APF, even though populations in both South American waters and the Southern Ocean are morphologically indistinguishable. Here, we revisit this finding using a high-resolution 2b-RAD (restriction-site-associated DNA) single-nucleotide polymorphism (SNP)-based approach, in addition to enlarged mitochondrial DNA data sets (16S rDNA, COI, and COII), for comparison to previous work. In total, 955 biallelic SNP loci confirmed the existence of strongly divergent populations on either side of the Drake Passage. Interestingly, genetic admixture was detected between South America and the Southern Ocean in five individuals on both sides of the APF, revealing evidence of recent or ongoing genetic contact. We also identified two differentiated populations on the Patagonian Shelf with six admixed individuals from these two populations. These findings suggest that the APF is a strong but imperfect barrier. Fluctuations in location and strength of the APF and ACC due to climate shifts may have profound consequences for levels of admixture or endemism in this region of the world.
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72
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Delroisse J, Ullrich-Lüter E, Blaue S, Ortega-Martinez O, Eeckhaut I, Flammang P, Mallefet J. A puzzling homology: a brittle star using a putative cnidarian-type luciferase for bioluminescence. Open Biol 2017; 7:rsob.160300. [PMID: 28381628 PMCID: PMC5413902 DOI: 10.1098/rsob.160300] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Accepted: 03/06/2017] [Indexed: 01/31/2023] Open
Abstract
Bioluminescence relies on the oxidation of a luciferin substrate catalysed by a luciferase enzyme. Luciferins and luciferases are generic terms used to describe a large variety of substrates and enzymes. Whereas luciferins can be shared by phylogenetically distant organisms which feed on organisms producing them, luciferases have been thought to be lineage-specific enzymes. Numerous light emission systems would then have co-emerged independently along the tree of life resulting in a plethora of non-homologous luciferases. Here, we identify for the first time a candidate luciferase of a luminous echinoderm, the ophiuroid Amphiura filiformis Phylogenomic analyses identified the brittle star predicted luciferase as homologous to the luciferase of the sea pansy Renilla (Cnidaria), contradicting with the traditional viewpoint according to which luciferases would generally be of convergent origins. The similarity between the Renilla and Amphiura luciferases allowed us to detect the latter using anti-Renilla luciferase antibodies. Luciferase expression was specifically localized in the spines which were demonstrated to be the bioluminescent organs in vivo However, enzymes homologous to the Renilla luciferase but unable to trigger light emission were also identified in non-luminous echinoderms and metazoans. Our findings strongly indicate that those enzymes, belonging to the haloalkane dehalogenase family, might then have been convergently co-opted into luciferases in cnidarians and echinoderms. In these two benthic suspension-feeding species, similar ecological pressures would constitute strong selective forces for the functional shift of these enzymes and the emergence of bioluminescence.
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Affiliation(s)
- Jérôme Delroisse
- Research Institute for Biosciences, Biology of Marine Organisms and Biomimetics, University of Mons - UMONS, 23 Place du Parc, 7000 Mons, Belgium
| | - Esther Ullrich-Lüter
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstr. 43, 10115 Berlin, Germany
| | - Stefanie Blaue
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstr. 43, 10115 Berlin, Germany
| | - Olga Ortega-Martinez
- Department of Marine Science, The Sven Lovén Centre for Marine Sciences - Kristineberg, University of Gothenburg, 45178 Fiskebäckskil, Sweden
| | - Igor Eeckhaut
- Research Institute for Biosciences, Biology of Marine Organisms and Biomimetics, University of Mons - UMONS, 23 Place du Parc, 7000 Mons, Belgium
| | - Patrick Flammang
- Research Institute for Biosciences, Biology of Marine Organisms and Biomimetics, University of Mons - UMONS, 23 Place du Parc, 7000 Mons, Belgium
| | - Jérôme Mallefet
- Marine Biology Laboratory, Université Catholique de Louvain, ELI, 3 Place Croix du Sud L7.04.06, 1348 Louvain-La-Neuve, Belgium
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73
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Okanishi M, Fujita T, Maekawa Y, Sasaki T. Non-destructive morphological observations of the fleshy brittle star, Asteronyx loveni using micro-computed tomography (Echinodermata, Ophiuroidea, Euryalida). Zookeys 2017; 663:1-19. [PMID: 28769615 PMCID: PMC5523172 DOI: 10.3897/zookeys.663.11413] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 02/23/2017] [Indexed: 11/26/2022] Open
Abstract
The first morphological observation of a euryalid brittle star, Asteronyx loveni, using non-destructive X-ray micro-computed tomography (µCT) was performed. The body of euryalids is covered by thick skin, and it is very difficult to observe the ossicles without dissolving the skin. Computed tomography with micrometer resolution (approximately 4.5-15.4 µm) was used to construct 3D images of skeletal ossicles and soft tissues in the ophiuroid's body. Shape and positional arrangement of taxonomically important ossicles were clearly observed without any damage to the body. Detailed pathways inside the vertebral ossicles, lateral arm plates, and arm spines for passage of nerves and water vascular structures were observed. Inter-vertebral muscles were also observed. Forms and 3D arrangements of many important taxonomical characters of the euryalids were scrutinized by µCT in high enough resolution for taxonomic description of ophiuroids.
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Affiliation(s)
- Masanori Okanishi
- Faculty of Science, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki, 310-8512 Japan
| | - Toshihiko Fujita
- National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba, Ibaraki, 305-0005 Japan
| | - Yu Maekawa
- University Museum, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-0033 Japan
| | - Takenori Sasaki
- University Museum, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-0033 Japan
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74
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Oba Y, Stevani CV, Oliveira AG, Tsarkova AS, Chepurnykh TV, Yampolsky IV. Selected Least Studied but not Forgotten Bioluminescent Systems. Photochem Photobiol 2017; 93:405-415. [DOI: 10.1111/php.12704] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/15/2016] [Indexed: 02/06/2023]
Affiliation(s)
- Yuichi Oba
- Department of Environmental Biology; Chubu University; Kasugai Japan
| | - Cassius V. Stevani
- Departamento de Química Fundamental; Instituto de Química; Universidade de São Paulo; São Paulo Brazil
| | - Anderson G. Oliveira
- Departamento de Oceanografia Física; Química e Geológica; Instituto Oceanográfico; Universidade de São Paulo; São Paulo Brazil
| | - Aleksandra S. Tsarkova
- Institute of Bioorganic Chemistry; Russian Academy of Sciences; Moscow Russia
- Pirogov Russian National Research Medical University; Moscow Russia
| | - Tatiana V. Chepurnykh
- Institute of Bioorganic Chemistry; Russian Academy of Sciences; Moscow Russia
- Pirogov Russian National Research Medical University; Moscow Russia
| | - Ilia V. Yampolsky
- Institute of Bioorganic Chemistry; Russian Academy of Sciences; Moscow Russia
- Pirogov Russian National Research Medical University; Moscow Russia
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75
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Weber AAT, Abi-Rached L, Galtier N, Bernard A, Montoya-Burgos JI, Chenuil A. Positive selection on sperm ion channels in a brooding brittle star: consequence of life-history traits evolution. Mol Ecol 2017; 26:3744-3759. [PMID: 28099777 DOI: 10.1111/mec.14024] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 01/04/2017] [Accepted: 01/09/2017] [Indexed: 01/12/2023]
Abstract
Closely related species are key models to investigate mechanisms leading to reproductive isolation and early stages of diversification, also at the genomic level. The brittle star cryptic species complex Ophioderma longicauda encompasses the sympatric broadcast-spawning species C3 and the internal brooding species C5. Here, we used de novo transcriptome sequencing and assembly in two closely related species displaying contrasting reproductive modes to compare their genetic diversity and to investigate the role of natural selection in reproductive isolation. We reconstructed 20 146 and 22 123 genes for C3 and C5, respectively, and characterized a set of 12 229 orthologs. Genetic diversity was 1.5-2 times higher in C3 compared to C5, confirming that species with low parental investment display higher levels of genetic diversity. Forty-eight genes were the targets of positive diversifying selection during the evolution of the two species. Notably, two genes (NHE and TetraKCNG) are sperm-specific ion channels involved in sperm motility. Ancestral sequence reconstructions show that natural selection targeted the two genes in the brooding species. This may result from an adaptation to the novel environmental conditions surrounding sperm in the brooding species, either directly affecting sperm or via an increase in male/female conflict. This phenomenon could have promoted prezygotic reproductive isolation between C3 and C5. Finally, the sperm receptors to egg chemoattractants differed between C3 and C5 in the ligand-binding region. We propose that mechanisms of species-specific gamete recognition in brittle stars occur during sperm chemotaxis (sperm attraction towards the eggs), contrary to other marine invertebrates where prezygotic barriers to interspecific hybridization typically occur before sperm-egg fusion.
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Affiliation(s)
- A A-T Weber
- Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE) - CNRS - IRD - UAPV, Aix-Marseille Université, Station Marine d'Endoume, Chemin de la Batterie des Lions, 13007, Marseille, France.,Zoological Institute, University of Basel, Vesalgasse 1, 4051, Basel, Switzerland
| | - L Abi-Rached
- Equipe ATIP, URMITE UM 63 CNRS 7278 IRD 198 Inserm U1095, IHU Méditerranée Infection, Aix-Marseille Université, Marseille, France
| | - N Galtier
- UMR 5554 Institut des Sciences de l'Evolution, CNRS, IRD, EPHE, Université de Montpellier, Place E. Bataillon, 34095, Montpellier, France
| | - A Bernard
- UMR 5554 Institut des Sciences de l'Evolution, CNRS, IRD, EPHE, Université de Montpellier, Place E. Bataillon, 34095, Montpellier, France
| | - J I Montoya-Burgos
- Department of Genetics and Evolution, University of Geneva, 4, Bvd d'Yvoy, 1205, Geneva, Switzerland
| | - A Chenuil
- Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE) - CNRS - IRD - UAPV, Aix-Marseille Université, Station Marine d'Endoume, Chemin de la Batterie des Lions, 13007, Marseille, France
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76
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O'Hara TD, Hugall AF, Thuy B, Stöhr S, Martynov AV. Restructuring higher taxonomy using broad-scale phylogenomics: The living Ophiuroidea. Mol Phylogenet Evol 2017; 107:415-430. [DOI: 10.1016/j.ympev.2016.12.006] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 12/05/2016] [Accepted: 12/07/2016] [Indexed: 10/20/2022]
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77
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Wilkie IC. Functional Morphology of the Arm Spine Joint and Adjacent Structures of the Brittlestar Ophiocomina nigra (Echinodermata: Ophiuroidea). PLoS One 2016; 11:e0167533. [PMID: 27974856 PMCID: PMC5156572 DOI: 10.1371/journal.pone.0167533] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Accepted: 11/15/2016] [Indexed: 11/18/2022] Open
Abstract
The skeletal morphology of the arm spine joint of the brittlestar Ophiocomina nigra was examined by scanning electron microscopy and the associated epidermis, connective tissue structures, juxtaligamental system and muscle by optical and transmission electron microscopy. The behaviour of spines in living animals was observed and two experiments were conducted to establish if the spine ligament is mutable collagenous tissue: these determined (1) if animals could detach spines to which plastic tags had been attached and (2) if the extension under constant load of isolated joint preparations was affected by high potassium stimulation. The articulation normally operates as a flexible joint in which the articular surfaces are separated by compliant connective tissue. The articular surfaces comprise a reniform apposition and peg-in-socket mechanical stop, and function primarily to stabilise spines in the erect position. Erect spines can be completely immobilised, which depends on the ligament having mutable tensile properties, as was inferred from the ability of animals to detach tagged spines and the responsiveness of isolated joint preparations to high potassium. The epidermis surrounding the joint has circumferential constrictions that facilitate compression folding and unfolding when the spine is inclined. The interarticular connective tissue is an acellular meshwork of collagen fibril bundles and may serve to reduce frictional forces between the articular surfaces. The ligament consists of parallel bundles of collagen fibrils and 7-14 nm microfibrils. Its passive elastic recoil contributes to the re-erection of inclined spines. The ligament is permeated by cell processes containing large dense-core vesicles, which belong to two types of juxtaligamental cells, one of which is probably peptidergic. The spine muscle consists of obliquely striated myocytes that are linked to the skeleton by extensions of their basement membranes. Muscle contraction may serve mainly to complete the process of spine erection by ensuring close contact between the articular surfaces.
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Affiliation(s)
- Iain C. Wilkie
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland, United Kingdom
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78
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Stöhr S, Martynov A. Paedomorphosis as an Evolutionary Driving Force: Insights from Deep-Sea Brittle Stars. PLoS One 2016; 11:e0164562. [PMID: 27806039 PMCID: PMC5091845 DOI: 10.1371/journal.pone.0164562] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 09/05/2016] [Indexed: 11/29/2022] Open
Abstract
Heterochronic development has been proposed to have played an important role in the evolution of echinoderms. In the class Ophiuroidea, paedomorphosis (retention of juvenile characters into adulthood) has been documented in the families Ophiuridae and Ophiolepididae but not been investigated on a broader taxonomic scale. Historical errors, confusing juvenile stages with paedomorphic species, show the difficulties in correctly identifying the effects of heterochrony on development and evolution. This study presents a detailed analysis of 40 species with morphologies showing various degrees of juvenile appearance in late ontogeny. They are compared to a range of early ontogenetic stages from paedomorphic and non-paedomorphic species. Both quantitative and qualitative measurements are taken and analysed. The results suggest that strongly paedomorphic species are usually larger than other species at comparable developmental stage. The findings support recent notions of polyphyletic origin of the families Ophiuridae and Ophiolepididae. The importance of paedomorphosis and its correct recognition for the practice of taxonomy and phylogeny are emphasized.
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Affiliation(s)
- Sabine Stöhr
- Swedish Museum of Natural History, Department of Zoology, Stockholm, Sweden
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79
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Thuy B, Stöhr S. A New Morphological Phylogeny of the Ophiuroidea (Echinodermata) Accords with Molecular Evidence and Renders Microfossils Accessible for Cladistics. PLoS One 2016; 11:e0156140. [PMID: 27227685 PMCID: PMC4882042 DOI: 10.1371/journal.pone.0156140] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 05/09/2016] [Indexed: 11/21/2022] Open
Abstract
Ophiuroid systematics is currently in a state of upheaval, with recent molecular estimates fundamentally clashing with traditional, morphology-based classifications. Here, we attempt a long overdue recast of a morphological phylogeny estimate of the Ophiuroidea taking into account latest insights on microstructural features of the arm skeleton. Our final estimate is based on a total of 45 ingroup taxa, including 41 recent species covering the full range of extant ophiuroid higher taxon diversity and 4 fossil species known from exceptionally preserved material, and the Lower Carboniferous Aganaster gregarius as the outgroup. A total of 130 characters were scored directly on specimens. The tree resulting from the Bayesian inference analysis of the full data matrix is reasonably well resolved and well supported, and refutes all previous classifications, with most traditional families discredited as poly- or paraphyletic. In contrast, our tree agrees remarkably well with the latest molecular estimate, thus paving the way towards an integrated new classification of the Ophiuroidea. Among the characters which were qualitatively found to accord best with our tree topology, we selected a list of potential synapomorphies for future formal clade definitions. Furthermore, an analysis with 13 of the ingroup taxa reduced to the lateral arm plate characters produced a tree which was essentially similar to the full dataset tree. This suggests that dissociated lateral arm plates can be analysed in combination with fully known taxa and thus effectively unlocks the extensive record of fossil lateral arm plates for phylogenetic estimates. Finally, the age and position within our tree implies that the ophiuroid crown-group had started to diversify by the Early Triassic.
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Affiliation(s)
- Ben Thuy
- Department of Palaeontology, Natural History Museum Luxembourg, Luxembourg-city, Luxembourg
- * E-mail: (BT); (SS)
| | - Sabine Stöhr
- Department of Zoology, Swedish Museum of Natural History, Stockholm, Sweden
- * E-mail: (BT); (SS)
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80
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Woolley SNC, Tittensor DP, Dunstan PK, Guillera-Arroita G, Lahoz-Monfort JJ, Wintle BA, Worm B, O’Hara TD. Deep-sea diversity patterns are shaped by energy availability. Nature 2016; 533:393-6. [DOI: 10.1038/nature17937] [Citation(s) in RCA: 150] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Accepted: 03/21/2016] [Indexed: 11/09/2022]
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81
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Delroisse J, Mallefet J, Flammang P. De Novo Adult Transcriptomes of Two European Brittle Stars: Spotlight on Opsin-Based Photoreception. PLoS One 2016; 11:e0152988. [PMID: 27119739 PMCID: PMC4847921 DOI: 10.1371/journal.pone.0152988] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 03/22/2016] [Indexed: 11/19/2022] Open
Abstract
Next generation sequencing (NGS) technology allows to obtain a deeper and more complete view of transcriptomes. For non-model or emerging model marine organisms, NGS technologies offer a great opportunity for rapid access to genetic information. In this study, paired-end Illumina HiSeqTM technology has been employed to analyse transcriptomes from the arm tissues of two European brittle star species, Amphiura filiformis and Ophiopsila aranea. About 48 million Illumina reads were generated and 136,387 total unigenes were predicted from A. filiformis arm tissues. For O. aranea arm tissues, about 47 million reads were generated and 123,324 total unigenes were obtained. Twenty-four percent of the total unigenes from A. filiformis show significant matches with sequences present in reference online databases, whereas, for O. aranea, this percentage amounts to 23%. In both species, around 50% of the predicted annotated unigenes were significantly similar to transcripts from the purple sea urchin, the closest species to date that has undergone complete genome sequencing and annotation. GO, COG and KEGG analyses were performed on predicted brittle star unigenes. We focused our analyses on the phototransduction actors involved in light perception. Firstly, two new echinoderm opsins were identified in O. aranea: one rhabdomeric opsin (homologous to vertebrate melanopsin) and one RGR opsin. The RGR-opsin is supposed to be involved in retinal regeneration while the r-opsin is suspected to play a role in visual-like behaviour. Secondly, potential phototransduction actors were identified in both transcriptomes using the fly (rhabdomeric) and mammal (ciliary) classical phototransduction pathways as references. Finally, the sensitivity of O.aranea to monochromatic light was investigated to complement data available for A. filiformis. The presence of microlens-like structures at the surface of dorsal arm plate of O. aranea could potentially explain phototactic behaviour differences between the two species. The results confirm (i) the ability of these brittle stars to perceive light using opsin-based photoreception, (ii) suggest the co-occurrence of both rhabdomeric and ciliary photoreceptors, and (iii) emphasise the complexity of light perception in this echinoderm class.
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Affiliation(s)
- Jérôme Delroisse
- School of Biological & Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Jérôme Mallefet
- Catholic University of Louvain-La-Neuve, Marine Biology Laboratory, Place croix du Sud, Louvain-La-Neuve–Belgium
| | - Patrick Flammang
- University of Mons—UMONS, Research Institute for Biosciences, Biology of Marine Organisms and Biomimetics, Mons, Belgium
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82
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Czarkwiani A, Ferrario C, Dylus DV, Sugni M, Oliveri P. Skeletal regeneration in the brittle star Amphiura filiformis. Front Zool 2016; 13:18. [PMID: 27110269 PMCID: PMC4841056 DOI: 10.1186/s12983-016-0149-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 04/12/2016] [Indexed: 12/17/2022] Open
Abstract
Background Brittle stars regenerate their whole arms post-amputation. Amphiura filiformis can now be used for molecular characterization of arm regeneration due to the availability of transcriptomic data. Previous work showed that specific developmental transcription factors known to take part in echinoderm skeletogenesis are expressed during adult arm regeneration in A. filiformis; however, the process of skeleton formation remained poorly understood. Here, we present the results of an in-depth microscopic analysis of skeletal morphogenesis during regeneration, using calcein staining, EdU labeling and in situ hybridization. Results To better compare different samples, we propose a staging system for the early A. filiformis arm regeneration stages based on morphological landmarks identifiable in living animals and supported by histological analysis. We show that the calcified spicules forming the endoskeleton first appear very early during regeneration in the dermal layer of regenerates. These spicules then mature into complex skeletal elements of the differentiated arm during late regeneration. The mesenchymal cells in the dermal area express the skeletal marker genes Afi-c-lectin, Afi-p58b and Afi-p19; however, EdU labeling shows that these dermal cells do not proliferate. Conclusions A. filiformis arms regenerate through a consistent set of developmental stages using a distalization-intercalation mode, despite variability in regeneration rate. Skeletal elements form in a mesenchymal cell layer that does not proliferate and thus must be supplied from a different source. Our work provides the basis for future cellular and molecular studies of skeleton regeneration in brittle stars. Electronic supplementary material The online version of this article (doi:10.1186/s12983-016-0149-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anna Czarkwiani
- Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Cinzia Ferrario
- Department of Biosciences, University of Milan, Milan, Italy
| | - David Viktor Dylus
- Department of Genetics, Evolution and Environment, University College London, London, UK ; Centre for Mathematics, Physics and Engineering in the Life Sciences and Experimental Biology, University College London, London, UK ; Present address: Department of Ecology and Evolution & Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Michela Sugni
- Department of Biosciences, University of Milan, Milan, Italy
| | - Paola Oliveri
- Department of Genetics, Evolution and Environment, University College London, London, UK ; Research Department of Genetics, Evolution and Environment, University College London, Room 426, Darwin Building, Gower Street, London, WC1E 6BT UK
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83
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Hunter RL, Brown LM, Alexander Hill C, Kroeger ZA, Rose SE. Additional insights into phylogenetic relationships of the Class Ophiuroidea (Echinodermata) from
rRNA
gene sequences. J ZOOL SYST EVOL RES 2016. [DOI: 10.1111/jzs.12135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Lydia M. Brown
- Department of Biology Abilene Christian University Abilene TX USA
- Western University of Health Sciences Pomona CA USA
| | | | - Zachary A. Kroeger
- Department of Biology Abilene Christian University Abilene TX USA
- University of Miami Miller School of Medicine Miami FL USA
| | - Shannon E. Rose
- Department of Biology Abilene Christian University Abilene TX USA
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84
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Barboza CADM, Martins CC, Lana PDC. Dissecting the distribution of brittle stars along a sewage pollution gradient indicated by organic markers. MARINE POLLUTION BULLETIN 2015; 100:438-444. [PMID: 26323862 DOI: 10.1016/j.marpolbul.2015.08.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 08/06/2015] [Accepted: 08/07/2015] [Indexed: 06/04/2023]
Abstract
We have assessed variation in brittle star distribution patterns along a contamination gradient identified by fecal steroids and aliphatic hydrocarbons in Paranaguá Bay, southern Brazil. A hierarchical design using multiple spatial scales (centimeters-kilometers) was applied. Generalized linear mixed models (GLMMs) were used to investigate the spatial and temporal variability of brittle stars. Main principal components from the contamination and environmental matrices were used to investigate the best explanatory dataset. The abundance of brittle stars was significantly lower in sites with high concentrations of fecal steroids and aliphatic hydrocarbons. The best model fitting always included components from the contamination gradients, which precludes a purely environmental driving of brittle star abundance. Variability in spatial scales lower than kilometers was probably driven by sediment characteristics. We highlighted the importance of a robust multi-scale sampling design for a better biological indication of coastal contamination.
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Affiliation(s)
- Carlos Alberto de Moura Barboza
- Universidade Federal do Paraná, Centro de Estudos do Mar, Av. Beira-mar, s/n, CEP, 83255-976 Paraná, Brazil; Universidade Federal do Estado do Rio de Janeiro, Instituto de Biociências, Av. Pasteur, 296, CEP: 22290-240 Rio de Janeiro, Brazil.
| | - César C Martins
- Universidade Federal do Paraná, Centro de Estudos do Mar, Av. Beira-mar, s/n, CEP, 83255-976 Paraná, Brazil
| | - Paulo da Cunha Lana
- Universidade Federal do Paraná, Centro de Estudos do Mar, Av. Beira-mar, s/n, CEP, 83255-976 Paraná, Brazil
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85
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Martynov A, Ishida Y, Irimura S, Tajiri R, O’Hara T, Fujita T. When Ontogeny Matters: A New Japanese Species of Brittle Star Illustrates the Importance of Considering both Adult and Juvenile Characters in Taxonomic Practice. PLoS One 2015; 10:e0139463. [PMID: 26509273 PMCID: PMC4625035 DOI: 10.1371/journal.pone.0139463] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 09/11/2015] [Indexed: 11/19/2022] Open
Abstract
Current taxonomy offers numerous approaches and methods for species delimitation and description. However, most of them are based on the adult characters and rarely suggest a dynamic representation of developmental transformations of taxonomically important features. Here we show how the underestimation of ontogenetic changes may result in long term lack of recognition of a new species of one of the most common ophiacanthid brittle stars (Echinodermata: Ophiuroidea) from the North Pacific. Based on vast material collected predominantly by various Japanese expeditions in the course of more than 50 years, and thorough study of appropriate type material, we revise the complex of three common species of the ophiuroid genus Ophiacantha which have been persistently confused with each other. The present study thus reveals the previously unrecognized new species Ophiacantha kokusai sp.nov. which is commonly distributed off the Pacific coast of Japan. The new species shows developmental differentiation from the closely related species Ophiacantha rhachophora H. L. Clark, 1911 and retains clearly expressed early juvenile features in the adult morphology. Another species, Ophiacantha clypeata Kyte, 1977, which had been separated from O. rhachophora, is in turn shown to be just a juvenile stage of another North Pacific species, Ophiacantha trachybactra H.L. Clark, 1911. For every species, detailed morphological data from both adult and juvenile specimens based on scanning electron microscopy are presented. A special grinding method showing complex internal features has been utilized for the first time. For all three species in this complex, a clear bathymetric differentiation is revealed: O. rhachophora predominantly inhabits shallow waters, 0-250 m, the new species O. kokusai lives deeper, at 250-600 m, and the third species, O. trachybactra, is found at 500-2,000 m. The present case clearly highlights the importance of considering developmental transformations, not only for a limited number of model organisms, but as part of the taxonomic process.
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Affiliation(s)
| | | | | | - Rie Tajiri
- Department of Earth Science, Waseda University, Tokyo, Japan
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86
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Hugall AF, O'Hara TD, Hunjan S, Nilsen R, Moussalli A. An Exon-Capture System for the Entire Class Ophiuroidea. Mol Biol Evol 2015; 33:281-94. [PMID: 26474846 PMCID: PMC4693979 DOI: 10.1093/molbev/msv216] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Exon-capture studies have typically been restricted to relatively shallow phylogenetic scales due primarily to hybridization constraints. Here, we present an exon-capture system for an entire class of marine invertebrates, the Ophiuroidea, built upon a phylogenetically diverse transcriptome foundation. The system captures approximately 90% of the 1,552 exon target, across all major lineages of the quarter-billion-year-old extant crown group. Key features of our system are 1) basing the target on an alignment of orthologous genes determined from 52 transcriptomes spanning the phylogenetic diversity and trimmed to remove anything difficult to capture, map, or align; 2) use of multiple artificial representatives based on ancestral state reconstructions rather than exemplars to improve capture and mapping of the target; 3) mapping reads to a multi-reference alignment; and 4) using patterns of site polymorphism to distinguish among paralogy, polyploidy, allelic differences, and sample contamination. The resulting data give a well-resolved tree (currently standing at 417 samples, 275,352 sites, 91% data-complete) that will transform our understanding of ophiuroid evolution and biogeography.
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Affiliation(s)
| | | | | | - Roger Nilsen
- Georgia Genomics Facility, University of Georgia
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87
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Black JG, Reichelt-Brushett AJ, Clark MW. The effect of copper and temperature on juveniles of the eurybathic brittle star Amphipholis squamata--exploring responses related to motility and the water vascular system. CHEMOSPHERE 2015; 124:32-39. [PMID: 25465949 DOI: 10.1016/j.chemosphere.2014.10.063] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 10/14/2014] [Accepted: 10/18/2014] [Indexed: 06/04/2023]
Abstract
The limited availability of test organisms that represent tropical and deeper water environments is a significant concern when assessing the risk of contaminants in these environments. Amphipholis squamata (Delle Chiaje 1828) is a widely distributed brittle star with many phylogenetic clades reported from different latitudes, and it also occurs from the intertidal zone to a depth of ∼1300 m. In the present study, the effect of copper on four behavioural responses and mortality of A. squamata were quantified at four different temperatures including 25, 20, 15 and 10°C. At 25°C the four behavioural responses and mortality were relatively sensitive to copper, with 96 h EC50 values of 25 (confidence interval 18-44), 24 (7-26), 32 (24-41), 29 (9-41) μg L(-1) for the measured ability to turn from the oral surface up to oral surface down, curling behaviour, tube foot movement, and tube foot retraction respectively. The average 96-h LC50 value for copper at 25°C was 46 μg L(-1). Some endpoints investigated showed significant effects of reduced temperature compared to the optimal temperature. These effects were enhanced with increasing copper concentrations and significant differences in copper toxicity between temperature treatments were most notable when measuring the ability to turn from the oral surface up to oral surface down where the EC50 changed from 25 (18 to 44) to 6 (-18 to 14) μg L(-1) with a reduction of temperature from 25 to 15°C. The results showed that A. squamata is relatively sensitive to copper and that further investigation into the effects of other stressors on these endpoints is warranted.
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Affiliation(s)
- James Geoffrey Black
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, PO Box 157, Lismore, NSW 2480, Australia
| | - Amanda Jean Reichelt-Brushett
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, PO Box 157, Lismore, NSW 2480, Australia.
| | - Malcolm W Clark
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, PO Box 157, Lismore, NSW 2480, Australia
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88
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Moles J, Figuerola B, Campanyà-Llovet N, Monleón-Getino T, Taboada S, Avila C. Distribution patterns in Antarctic and Subantarctic echinoderms. Polar Biol 2015. [DOI: 10.1007/s00300-014-1640-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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89
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Naughton K, O’Hara T, Appleton B, Cisternas P. Antitropical distributions and species delimitation in a group of ophiocomid brittle stars (Echinodermata: Ophiuroidea: Ophiocomidae). Mol Phylogenet Evol 2014; 78:232-44. [DOI: 10.1016/j.ympev.2014.05.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 05/06/2014] [Accepted: 05/14/2014] [Indexed: 10/25/2022]
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90
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O'Hara TD, Hugall AF, Thuy B, Moussalli A. Phylogenomic resolution of the class Ophiuroidea unlocks a global microfossil record. Curr Biol 2014; 24:1874-9. [PMID: 25065752 DOI: 10.1016/j.cub.2014.06.060] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 05/23/2014] [Accepted: 06/23/2014] [Indexed: 11/17/2022]
Abstract
Our understanding of the origin, evolution, and biogeography of seafloor fauna is limited because we have insufficient spatial and temporal data to resolve underlying processes. The abundance and wide distribution of modern and disarticulated fossil Ophiuroidea, including brittle stars and basket stars, make them an ideal model system for global marine biogeography if we have the phylogenetic framework necessary to link extant and fossil morphology in an evolutionary context. Here we construct a phylogeny from a highly complete 425-gene, 61-taxa transcriptome-based data set covering 15 of the 18 ophiuroid families and representatives of all extant echinoderm classes. We calibrate our phylogeny with a series of novel fossil discoveries from the early Mesozoic. We confirm the traditional paleontological view that ophiuroids are sister to the asteroids and date the crown group Ophiuroidea to the mid-Permian (270 ± 30 mega-annum). We refute all historical classification schemes of the Ophiuroidea based on gross structural characters but find strong congruence with schemes based on lateral arm plate microstructure and the temporal appearance of various plate morphologies in the fossil record. The verification that these microfossils contain phylogenetically informative characters unlocks their potential to advance our understanding of marine biogeographical processes.
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Affiliation(s)
| | - Andrew F Hugall
- Museum Victoria, GPO Box 666, Melbourne, VIC 3001, Australia
| | - Ben Thuy
- Section Paléontologie, Musée National d'Histoire Naturelle du Luxembourg, 24 Rue Münster, 2160 Luxembourg
| | - Adnan Moussalli
- Museum Victoria, GPO Box 666, Melbourne, VIC 3001, Australia
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91
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Molecular phylogeny based on increased number of species and genes revealed more robust family-level systematics of the order Euryalida (Echinodermata: Ophiuroidea). Mol Phylogenet Evol 2013; 69:566-80. [DOI: 10.1016/j.ympev.2013.07.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 07/04/2013] [Accepted: 07/19/2013] [Indexed: 11/23/2022]
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92
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Martín-Ledo R, López-González PJ. Brittle stars from Southern Ocean (Echinodermata: Ophiuroidea). Polar Biol 2013. [DOI: 10.1007/s00300-013-1411-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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93
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Gondim AI, Alonso C, Dias TLP, Manso CLC, Christoffersen ML. A taxonomic guide to the brittle-stars (Echinodermata, Ophiuroidea) from the State of Paraíba continental shelf, Northeastern Brazil. Zookeys 2013:45-96. [PMID: 23794923 PMCID: PMC3689063 DOI: 10.3897/zookeys.307.4673] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Accepted: 05/16/2013] [Indexed: 11/19/2022] Open
Abstract
We provide the first annotated checklist of ophiuroids from the continental shelf of the State of Paraíba, northeastern Brazil. Identification keys and taxonomic diagnoses for 23 species, belonging to 14 genera and 8 families, are provided. The material is deposited in the Invertebrate Collection Paulo Young, at the Federal University of Paraíba. Ophiopsila hartmeyeri represents the first record for the northeastern region of Brazil, while Ophiolepis impressa, Ophiolepis paucispina, Amphiura stimpsoni, Amphiodia riisei, Ophiactis quinqueradia, Ophiocoma wendtii and Ophionereis olivaceae are new records for the State of Paraíba. The number of species known for the state was increased from 16 to 23, representing approximately 17% of the species known for Brazil and 54% of the species known for northeastern Brazil. The recorded fauna has a large geographical and bathymetrical distribution.
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Affiliation(s)
- Anne I Gondim
- Universidade Federal da Paraíba, Programa de Pós-Graduação em Ciências Biológicas (Zoologia), Laboratório de Invertebrados Paulo Young (LIPY), João Pessoa, PB.CEP. 58059-900, Brasil
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94
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Granja-Fernández R, Hernández-Moreno P, Bastida-Zavala R. First record of the association between Malmgreniella cf. variegata (Polychaeta, Polynoidae) and Ophionereis annulata (Echinodermata, Ophionereididae) in the Mexican Pacific. Symbiosis 2013. [DOI: 10.1007/s13199-013-0239-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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95
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Costello MJ, Bouchet P, Boxshall G, Fauchald K, Gordon D, Hoeksema BW, Poore GCB, van Soest RWM, Stöhr S, Walter TC, Vanhoorne B, Decock W, Appeltans W. Global coordination and standardisation in marine biodiversity through the World Register of Marine Species (WoRMS) and related databases. PLoS One 2013; 8:e51629. [PMID: 23505408 PMCID: PMC3541386 DOI: 10.1371/journal.pone.0051629] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Accepted: 11/08/2012] [Indexed: 12/02/2022] Open
Abstract
The World Register of Marine Species is an over 90% complete open-access inventory of all marine species names. Here we illustrate the scale of the problems with species names, synonyms, and their classification, and describe how WoRMS publishes online quality assured information on marine species. Within WoRMS, over 100 global, 12 regional and 4 thematic species databases are integrated with a common taxonomy. Over 240 editors from 133 institutions and 31 countries manage the content. To avoid duplication of effort, content is exchanged with 10 external databases. At present WoRMS contains 460,000 taxonomic names (from Kingdom to subspecies), 368,000 species level combinations of which 215,000 are currently accepted marine species names, and 26,000 related but non-marine species. Associated information includes 150,000 literature sources, 20,000 images, and locations of 44,000 specimens. Usage has grown linearly since its launch in 2007, with about 600,000 unique visitors to the website in 2011, and at least 90 organisations from 12 countries using WoRMS for their data management. By providing easy access to expert-validated content, WoRMS improves quality control in the use of species names, with consequent benefits to taxonomy, ecology, conservation and marine biodiversity research and management. The service manages information on species names that would otherwise be overly costly for individuals, and thus minimises errors in the application of nomenclature standards. WoRMS' content is expanding to include host-parasite relationships, additional literature sources, locations of specimens, images, distribution range, ecological, and biological data. Species are being categorised as introduced (alien, invasive), of conservation importance, and on other attributes. These developments have a multiplier effect on its potential as a resource for biodiversity research and management. As a consequence of WoRMS, we are witnessing improved communication within the scientific community, and anticipate increased taxonomic efficiency and quality control in marine biodiversity research and management.
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Affiliation(s)
- Mark J Costello
- Leigh Marine Laboratory, University of Auckland, Auckland, New Zealand.
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Martín-Ledo R, Sands CJ, López-González PJ. A new brooding species of brittle star (Echinodermata: Ophiuroidea) from Antarctic waters. Polar Biol 2012. [DOI: 10.1007/s00300-012-1242-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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