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Grenier C, Griesshaber E, Schmahl W, Berning B, Checa AG. Skeletal microstructures of cheilostome bryozoans (phylum Bryozoa, class Gymnolaemata): crystallography and secretion patterns. MARINE LIFE SCIENCE & TECHNOLOGY 2024; 6:405-424. [PMID: 39219676 PMCID: PMC11358562 DOI: 10.1007/s42995-024-00233-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 04/30/2024] [Indexed: 09/04/2024]
Abstract
Gymnolaemata bryozoans produce CaCO3 skeletons of either calcite, aragonite, or both. Despite extensive research, their crystallography and biomineralization patterns remain unclear. We present a detailed study of the microstructures, mineralogy, and crystallography of eight extant cheilostome species using scanning electron microscopy, electron backscatter diffraction, atomic force microscopy, and micro-computed tomography. We distinguished five basic microstructures, three calcitic (tabular, irregularly platy, and granular), and two aragonitic (granular-platy and fibrous). The calcitic microstructures consist of crystal aggregates that transition from tabular or irregularly platy to granular assemblies. Fibrous aragonite consists of fibers arranged into spherulites. In all cases, the crystallographic textures are axial, and stronger in aragonite than in calcite, with the c-axis as the fiber axis. We reconstruct the biomineralization sequence in the different species by considering the distribution and morphology of the growth fronts of crystals and the location of the secretory epithelium. In bimineralic species, calcite formation always predates aragonite formation. In interior compound walls, growth proceeds from the cuticle toward the zooecium interior. We conclude that, with the exception of tabular calcite, biomineralization is remote and occurs within a relatively wide extrapallial space, which is consistent with the inorganic-like appearance of the microstructures. This biomineralization mode is rare among invertebrates. Supplementary Information The online version contains supplementary material available at 10.1007/s42995-024-00233-1.
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Affiliation(s)
- Christian Grenier
- Departamento de Estratigrafía y Paleontología, Universidad de Granada, 18071 Granada, Spain
| | - Erika Griesshaber
- Department of Earth and Environmental Sciences, Ludwig-Maximilians Universität, 80333 Munich, Germany
| | - Wolfgang Schmahl
- Department of Earth and Environmental Sciences, Ludwig-Maximilians Universität, 80333 Munich, Germany
| | - Björn Berning
- Institute for Geology, University of Hamburg, 20146 Hamburg, Germany
| | - Antonio G. Checa
- Departamento de Estratigrafía y Paleontología, Universidad de Granada, 18071 Granada, Spain
- Instituto Andaluz de Ciencias de La Tierra, CSIC-Universidad de Granada, 18100 Armilla, Spain
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2
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Zhao J, Li Y, Selden PA. Two new metazoans from the Cambrian Guanshan biota of China. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2023.1160530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
Abstract
Sessile epibenthos were diverse and played important part in the process of energy flow in the Cambrian marine ecosystem. Based on new specimens from the Gaoloufang Section of the Wulongqing Formation, we describe two new representatives of the group that show character traits with cnidarians and bryozoans. If confirmed, the new material can help us understand the origin and early evolution of these two phyla. The discovery of more sessile epibenthos suggests that the benthic ecosystem of the Guanshan biota (Cambrian Series 2, Stage 4) is more diverse than previously thought.
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3
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Osés GL, Wood R, Romero GR, Evangelista Martins Prado GM, Bidola P, Herzen J, Pfeiffer F, Stampar SN, Alves Forancelli Pacheco ML. Ediacaran Corumbella has a cataphract calcareous skeleton with controlled biomineralization. iScience 2022; 25:105676. [PMID: 36561886 PMCID: PMC9763863 DOI: 10.1016/j.isci.2022.105676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 12/02/2021] [Accepted: 11/22/2022] [Indexed: 11/27/2022] Open
Abstract
Corumbella is a terminal Ediacaran tubular, benthic fossil of debated morphology, composition, and biological affinity. Here, we show that Corumbella had a biomineralized skeleton, with a bilayered construction of imbricated calcareous plates and rings (sclerites) yielding a cataphract organization, that enhanced flexibility. Each sclerite likely possessed a laminar microfabric with consistent crystallographic orientation, within an organic matrix. Original aragonitic mineralogy is supported by relict aragonite and elevated Sr (mean = ca. 11,800 ppm in central parts of sclerites). In sum, the presence of a polarisation axis, sclerites with a laminar microfabric, and a cataphract skeletal organization reminiscent of early Cambrian taxa, are all consistent with, but not necessarily indicative of, a bilaterian affinity. A cataphract skeleton with an inferred complex microstructure confirms the presence of controlled biomineralization in metazoans by the terminal Ediacaran, and offers insights into the evolution of development and ecology at the root of the 'Cambrian radiation'.
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Affiliation(s)
- Gabriel Ladeira Osés
- Programa de Pós-Graduação em Ecologia e Recursos Naturais, Universidade Federal de São Carlos, Rodovia Washington Luís, Km 235, São Carlos-SP 13565-905, Brazil,School of GeoSciences, University of Edinburgh, James Hutton Road, Edinburgh EH9 3FE, UK,Laboratório de Paleobiologia e Astrobiologia, Universidade Federal de São Carlos, Rodovia João Leme dos Santos, Km 110, Sorocaba-SP 18052-780, Brazil,Programa de Pós-Doutorado, Instituto de Física, Universidade de São Paulo, Rua do Matão, 1371, São Paulo-SP 05508-090, Brazil
| | - Rachel Wood
- School of GeoSciences, University of Edinburgh, James Hutton Road, Edinburgh EH9 3FE, UK
| | - Guilherme Raffaeli Romero
- Instituto de Geociências, Universidade de São Paulo, Rua do Lago, 562, São Paulo-SP 05508-080, Brazil
| | | | - Pidassa Bidola
- Institute of Materials Physics, Helmholtz-Zentrum Hereon, Max Plank Straße 1, 21502 Geesthacht, Germany
| | - Julia Herzen
- Research Group of Physics of Biomedical Imaging, School of Natural Sciences, Technical University of Munich, James-Franck Straße 1, 85748 Garching b. München, Germany,Munich Institute of Biomedical Engineering, Technical University of Munich, Boltzmannstr. 11, 85748 Garching b. München, Germany
| | - Franz Pfeiffer
- Munich Institute of Biomedical Engineering, Technical University of Munich, Boltzmannstr. 11, 85748 Garching b. München, Germany,Chair of Biomedical Physics, Department of Physics, School of Natural Sciences, Technical University of Munich, James-Franck Straße 1, 85748 Garching b. München, Germany,Department of Diagnostic and Interventional Radiology, School of Medicine and Klinikum rechts der Isar, Technical University of Munich, Ismaninger Straße 22D, 81675 Munich, Germany
| | - Sérgio Nascimento Stampar
- Laboratório de Evolução e Diversidade Aquática, Departamento de Ciências Biológicas, Faculdade de Ciências - Câmpus de Bauru, Universidade Estadual Paulista, Av. Eng. Luiz Edmundo Carrijo Coube, 14-01, Bauru-SP 17033-360, Brazil
| | - Mírian Liza Alves Forancelli Pacheco
- Laboratório de Paleobiologia e Astrobiologia, Universidade Federal de São Carlos, Rodovia João Leme dos Santos, Km 110, Sorocaba-SP 18052-780, Brazil,Programa de Pós-Doutorado, Instituto de Física, Universidade de São Paulo, Rua do Matão, 1371, São Paulo-SP 05508-090, Brazil,Corresponding author
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4
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Understanding the crystallographic and nanomechanical properties of bryozoans. J Struct Biol 2022; 214:107882. [PMID: 35850322 DOI: 10.1016/j.jsb.2022.107882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 07/08/2022] [Accepted: 07/12/2022] [Indexed: 11/23/2022]
Abstract
This study examines how microscale differences in skeletal ultrastructure affect the crystallographic and nanomechanical properties of two related bryozoan species: (i) Hornera currieae, which is found at relatively quiescent depths of c. 1000 m, and (ii) Hornera robusta, which lives at depths of 50-400 m where it is exposed to currents and storm waves. Microstructural and Electron Backscatter Diffraction (EBSD) observations show that in both species the secondary walls are composed of low-Mg calcite crystallites that grow with their c-axes perpendicular to the wall. Branches in H. currieae develop a strong preferred orientation of the calcite c-axes, while in H. robusta the c-axes are more scattered. Microstructural observations suggest that the degree of scattering is controlled by the underlying morphology of the skeletons: in H. currieae the laminated branch walls are smooth and relatively uninterrupted, whereas the wall architecture of H. robusta is modified by numerous deflections, forming pustules and ridges associated with microscopic tubules. Modelling of the Young's modulus and measurements of nanoindentation hardness indicate that the observed scattering of the crystallite c-axes affects the elastic modulus and nanohardness of the branches, and therefore controls the mechanical properties of the skeletal walls. At relatively high pressure in deep waters, the anisotropic skeletal architecture of H. currieae is aimed at concentrating elasticity normal to the skeleton wall. In comparison, in the relatively shallow and active hydrographic regime of the continental shelf, the elastically isotropic skeleton of H. robusta is designed to increase protection from external predators and stronger omni-directional currents.
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5
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Batson PB, Tamberg Y, Taylor PD. Composite branch construction by dual autozooidal budding modes in hornerids (Bryozoa: Cyclostomatida). J Morphol 2022; 283:783-804. [DOI: 10.1002/jmor.21469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 03/07/2022] [Accepted: 03/16/2022] [Indexed: 11/08/2022]
Affiliation(s)
- P. B. Batson
- Department of Marine ScienceUniversity of OtagoDunedin9054New Zealand
| | - Y. Tamberg
- Department of Marine ScienceUniversity of OtagoDunedin9054New Zealand
| | - P. D. Taylor
- Department of Earth SciencesNatural History MuseumLondonSW7 5BD
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Krzemińska M, Piwoni-Piórewicz A, Shunatova N, Duczmal-Czernikiewicz A, Muszyński A, Kubiak M, Kukliński P. Bryozoan carbonate skeletal geochemical composition in the White Sea compared with neighbouring seas. MARINE ENVIRONMENTAL RESEARCH 2022; 173:105542. [PMID: 34896921 DOI: 10.1016/j.marenvres.2021.105542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 12/01/2021] [Accepted: 12/04/2021] [Indexed: 06/14/2023]
Abstract
A fundamental question underlying skeletal mineral secretion in marine invertebrates is the extent to which the physico-chemical parameters of seawater (e.g., salinity, temperature) and animal physiology influence their skeletal mineralogy and chemistry. Groups with more complex mineralogies, such as bryozoans, have the ability to actively control their own skeletal composition in response to environmental conditions and could be considered indicators of global environmental change. Thus, this study aims to reveal how the unique environmental conditions of low salinity (circa 24-26), prominent seasonality and semi-isolation of the White Sea (WS) subarctic region caused by the last glaciation (12,000 ya) affect the carbonate skeletal geochemical composition of bryozoans. X-ray diffraction analysis of 27 bryozoan taxa (92 specimens) revealed a completely monomineral calcite composition of skeletons with a mean value of 6.9 ± 1.8 mol% MgCO3 and moderate variability at the species and family levels. Most specimens (43.5%) precipitated skeletal magnesium within the range of 7-8 mol% MgCO3. Regional analysis of the mineralogical profile of the White Sea bryozoans shows that they differ statistically from bryozoan species living in the neighbouring Arctic and temperate Scotland regions in terms of magnesium content in calcite (approximately 7 mol% MgCO3 in the White Sea versus 5 mol% MgCO3 in other regions). We suggest that the effect of low salinity on magnesium content was compensated by relatively high summer temperature causing rapid growth and calcification and possibly resulted in the increased Mg contents in the White Sea (WS) bryozoans. However, on a local scale (between sampling locations), the influence of temperature and salinity could be excluded as a source of observed intraspecific variability. The concentration of MgCO3 in skeletons of the studied bryozoans is controlled by other environmental variables or is species-specific and depends on the physiological processes of the organisms.
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Affiliation(s)
- Małgorzata Krzemińska
- Institute of Oceanology Polish Academy of Sciences, Powstańców Warszawy 55, 81-712, Sopot, Poland.
| | - Anna Piwoni-Piórewicz
- Institute of Oceanology Polish Academy of Sciences, Powstańców Warszawy 55, 81-712, Sopot, Poland; Institute of Oceanography, University of Gdańsk, Al. Piłsudskiego 46, 81-378, Gdynia
| | - Natalia Shunatova
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Universitetskaja Nab. 7/9, 199034, Saint Petersburg, Russia
| | - Agata Duczmal-Czernikiewicz
- Institute of Geology, Adam Mickiewicz University of Poznan, Ul. Bogumiła Krygowskiego 12, 61-680, Poznań, Poland
| | - Andrzej Muszyński
- Institute of Geology, Adam Mickiewicz University of Poznan, Ul. Bogumiła Krygowskiego 12, 61-680, Poznań, Poland
| | - Michał Kubiak
- Institute of Geology, Adam Mickiewicz University of Poznan, Ul. Bogumiła Krygowskiego 12, 61-680, Poznań, Poland
| | - Piotr Kukliński
- Institute of Oceanology Polish Academy of Sciences, Powstańców Warszawy 55, 81-712, Sopot, Poland
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7
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Checa AG, Linares F, Grenier C, Griesshaber E, Rodríguez-Navarro AB, Schmahl WW. The argonaut constructs its shell via physical self-organization and coordinated cell sensorial activity. iScience 2021; 24:103288. [PMID: 34765916 PMCID: PMC8571729 DOI: 10.1016/j.isci.2021.103288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 09/29/2021] [Accepted: 10/13/2021] [Indexed: 11/14/2022] Open
Abstract
The shell of the cephalopod Argonauta consists of two layers of fibers that elongate perpendicular to the shell surfaces. Fibers have a high-Mg calcitic core sheathed by thin organic membranes (>100 nm) and configurate a polygonal network in cross section. Their evolution has been studied by serial sectioning with electron microscopy-associated techniques. During growth, fibers with small cross-sectional areas shrink, whereas those with large sections widen. It is proposed that fibers evolve as an emulsion between the fluid precursors of both the mineral and organic phases. When polygons reach big cross-sectional areas, they become subdivided by new membranes. To explain both the continuation of the pattern and the subdivision process, the living cells from the mineralizing tissue must perform contact recognition of the previously formed pattern and subsequent secretion at sub-micron scale. Accordingly, the fabrication of the argonaut shell proceeds by physical self-organization together with direct cellular activity. The shell consists of a polygonal organic pattern that evolves as a physical system An emulsion model accounts for the configuration of the pattern Mean polygon size and number is kept by the additional splitting of large polygons Cell sensitivity explains the propagation of the pattern and polygon splitting
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Affiliation(s)
- Antonio G Checa
- Departamento de Estratigrafía y Paleontología, Universidad de Granada, 18071 Granada, Spain.,Instituto Andaluz de Ciencias de la Tierra, CSIC-Universidad de Granada, 18100 Armilla, Spain
| | - Fátima Linares
- Centro de Instrumentación Científica, Universidad de Granada, 18071 Granada, Spain
| | - Christian Grenier
- Departamento de Estratigrafía y Paleontología, Universidad de Granada, 18071 Granada, Spain
| | - Erika Griesshaber
- Department für Geo- und Umweltwissenschaften, Ludwig-Maximilians-Universität München, 80333 München, Germany
| | | | - Wolfgang W Schmahl
- Department für Geo- und Umweltwissenschaften, Ludwig-Maximilians-Universität München, 80333 München, Germany
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8
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Abstract
Bryozoans (also known as ectoprocts or moss animals) are aquatic, dominantly sessile, filter-feeding lophophorates that construct an organic or calcareous modular colonial (clonal) exoskeleton1–3. The presence of six major orders of bryozoans with advanced polymorphisms in lower Ordovician rocks strongly suggests a Cambrian origin for the largest and most diverse lophophorate phylum2,4–8. However, a lack of convincing bryozoan fossils from the Cambrian period has hampered resolution of the true origins and character assembly of the earliest members of the group. Here we interpret the millimetric, erect, bilaminate, secondarily phosphatized fossil Protomelission gatehousei9 from the early Cambrian of Australia and South China as a potential stem-group bryozoan. The monomorphic zooid capsules, modular construction, organic composition and simple linear budding growth geometry represent a mixture of organic Gymnolaemata and biomineralized Stenolaemata character traits, with phylogenetic analyses identifying P. gatehousei as a stem-group bryozoan. This aligns the origin of phylum Bryozoa with all other skeletonized phyla in Cambrian Age 3, pushing back its first occurrence by approximately 35 million years. It also reconciles the fossil record with molecular clock estimations of an early Cambrian origination and subsequent Ordovician radiation of Bryozoa following the acquisition of a carbonate skeleton10–13. Interpretation of the early Cambrian fossil Protomelission gatehousei9 as a potential stem-group bryozoan realigns the fossil record with molecular clock estimations of the origins of Bryozoa.
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9
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Shore AJ, Wood RA, Butler IB, Zhuravlev AY, McMahon S, Curtis A, Bowyer FT. Ediacaran metazoan reveals lophotrochozoan affinity and deepens root of Cambrian Explosion. SCIENCE ADVANCES 2021; 7:7/1/eabf2933. [PMID: 33523867 PMCID: PMC7775780 DOI: 10.1126/sciadv.abf2933] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 11/09/2020] [Indexed: 05/12/2023]
Abstract
Through exceptional preservation, we establish a phylogenetic connection between Ediacaran and Cambrian metazoans. We describe the first three-dimensional, pyritized soft tissue in Namacalathus from the Ediacaran Nama Group, Namibia, which follows the underlying form of a stalked, cup-shaped, calcitic skeleton, with six radially arranged lobes projecting into an apical opening and lateral lumens. A thick body wall and probable J-shaped gut are present within the cup, and the middle layer of the often-spinose skeleton and skeletal pores are selectively pyritized, supporting an organic-rich composition and tripartite construction with possible sensory punctae. These features suggest a total group lophotrochozoan affinity. These morphological data support molecular phylogenies and demonstrates that the origin of modern lophotrochozoan phyla, and their ability to biomineralize, had deep roots in the Ediacaran.
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Affiliation(s)
- A J Shore
- School of GeoSciences, University of Edinburgh, James Hutton Road, Edinburgh EH9 3FE, UK.
| | - R A Wood
- School of GeoSciences, University of Edinburgh, James Hutton Road, Edinburgh EH9 3FE, UK
| | - I B Butler
- School of GeoSciences, University of Edinburgh, James Hutton Road, Edinburgh EH9 3FE, UK
| | - A Yu Zhuravlev
- Department of Biological Evolution, Faculty of Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow 119991, Russia
| | - S McMahon
- School of GeoSciences, University of Edinburgh, James Hutton Road, Edinburgh EH9 3FE, UK
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, James Clerk Maxwell Building, Peter Guthrie Tait Road, Edinburgh EH9 3FD, UK
| | - A Curtis
- School of GeoSciences, University of Edinburgh, James Hutton Road, Edinburgh EH9 3FE, UK
| | - F T Bowyer
- School of GeoSciences, University of Edinburgh, James Hutton Road, Edinburgh EH9 3FE, UK
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10
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Batson PB, Tamberg Y, Taylor PD, Gordon DP, Smith AM. Skeletal resorption in bryozoans: occurrence, function and recognition. Biol Rev Camb Philos Soc 2020; 95:1341-1371. [PMID: 32558290 DOI: 10.1111/brv.12613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 04/29/2020] [Accepted: 04/30/2020] [Indexed: 11/30/2022]
Abstract
Skeletal resorption - the physiological removal of mineralised parts by an organism - is an important morphogenetic process in bryozoans. Reports of its occurrence and function across the phylum are patchy, however, and have not previously been synthesised. Here we show that resorption occurs routinely across a wide range of bryozoan clades, colony sizes, growth forms, ontogenetic stages, body wall types, skeletal ultrastructures and mineralogies. Beginning in the early Paleozoic, different modes and functions of resorption have evolved convergently among disparate groups, highlighting its utility as a morphogenetic mode in this phylum. Its functions include branch renovation, formation of branch articulations, excavation of reproductive chambers, part-shedding, and creation of access portals for budding beyond previously formed skeletal walls. Bryozoan skeletons can be altered by resorption at microscopic, zooidal and colony-wide scales, typically with a fine degree of control and coordination. We classified resorption patterns in bryozoans according to the morphology and function of the resorption zone (window formation, abscission or excavation), timing within the life of the skeletal element resorbed (primary or secondary), and scale of operation (zooidal or multizooidal). Skeletal resorption is probably greatly underestimated in terms of its utility and role in bryozoan life history, and its prevalence across taxa, especially in fossil forms. It is reported proportionally more frequently in stenolaemates than in gymnolaemates. Some modes of resorption potentially alter or remove the spatial-temporal record of calcification preserved within a skeleton. Consequently, knowledge that resorption has occurred can be relevant for some common applications of skeletal analysis, such as palaeoenvironmental interpretation, or growth and ageing studies. To aid recognition we provide scanning electron microscopy, backscattered electron scanning electron microscopy and transmission electron microscopy examples of skeletal ultrastuctures modified by resorption.
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Affiliation(s)
- Peter B Batson
- Department of Marine Science, University of Otago, 310 Castle Street, Dunedin, 9054, New Zealand
| | - Yuta Tamberg
- Department of Marine Science, University of Otago, 310 Castle Street, Dunedin, 9054, New Zealand
| | - Paul D Taylor
- Departments of Earth & Life Sciences , Natural History Museum, Cromwell Road, London, SW7 5BD, U.K
| | - Dennis P Gordon
- NIWA, Private Bag 14901, Kilbirnie, Wellington, 6241, New Zealand
| | - Abigail M Smith
- Department of Marine Science, University of Otago, 310 Castle Street, Dunedin, 9054, New Zealand
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11
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Schwaha TF, Ostrovsky AN, Wanninger A. Key novelties in the evolution of the aquatic colonial phylum Bryozoa: evidence from soft body morphology. Biol Rev Camb Philos Soc 2020; 95:696-729. [PMID: 32032476 PMCID: PMC7317743 DOI: 10.1111/brv.12583] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 01/10/2020] [Accepted: 01/14/2020] [Indexed: 11/29/2022]
Abstract
Molecular techniques are currently the leading tools for reconstructing phylogenetic relationships, but our understanding of ancestral, plesiomorphic and apomorphic characters requires the study of the morphology of extant forms for testing these phylogenies and for reconstructing character evolution. This review highlights the potential of soft body morphology for inferring the evolution and phylogeny of the lophotrochozoan phylum Bryozoa. This colonial taxon comprises aquatic coelomate filter-feeders that dominate many benthic communities, both marine and freshwater. Despite having a similar bauplan, bryozoans are morphologically highly diverse and are represented by three major taxa: Phylactolaemata, Stenolaemata and Gymnolaemata. Recent molecular studies resulted in a comprehensive phylogenetic tree with the Phylactolaemata sister to the remaining two taxa, and Stenolaemata (Cyclostomata) sister to Gymnolaemata. We plotted data of soft tissue morphology onto this phylogeny in order to gain further insights into the origin of morphological novelties and character evolution in the phylum. All three larger clades have morphological apomorphies assignable to the latest molecular phylogeny. Stenolaemata (Cyclostomata) and Gymnolaemata were united as monophyletic Myolaemata because of the apomorphic myoepithelial and triradiate pharynx. One of the main evolutionary changes in bryozoans is a change from a body wall with two well-developed muscular layers and numerous retractor muscles in Phylactolaemata to a body wall with few specialized muscles and few retractors in the remaining bryozoans. Such a shift probably pre-dated a body wall calcification that evolved independently at least twice in Bryozoa and resulted in the evolution of various hydrostatic mechanisms for polypide protrusion. In Cyclostomata, body wall calcification was accompanied by a unique detachment of the peritoneum from the epidermis to form the hydrostatic membraneous sac. The digestive tract of the Myolaemata differs from the phylactolaemate condition by a distinct ciliated pylorus not present in phylactolaemates. All bryozoans have a mesodermal funiculus, which is duplicated in Gymnolaemata. A colonial system of integration (CSI) of additional, sometimes branching, funicular cords connecting neighbouring zooids via pores with pore-cell complexes evolved at least twice in Gymnolaemata. The nervous system in all bryozoans is subepithelial and concentrated at the lophophoral base and the tentacles. Tentacular nerves emerge intertentacularly in Phylactolaemata whereas they partially emanate directly from the cerebral ganglion or the circum-oral nerve ring in myolaemates. Overall, morphological evidence shows that ancestral forms were small, colonial coelomates with a muscular body wall and a U-shaped gut with ciliary tentacle crown, and were capable of asexual budding. Coloniality resulted in many novelties including the origin of zooidal polymorphism, an apomorphic landmark trait of the Myolaemata.
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Affiliation(s)
- Thomas F. Schwaha
- Department of Evolutionary Biology, Integrative Zoology, Faculty of Life SciencesUniversity of ViennaVienna1090Austria
| | - Andrew N. Ostrovsky
- Department of Palaeontology, Faculty of Earth Sciences, Geography and AstronomyUniversity of ViennaVienna1090Austria
- Department of Invertebrate Zoology, Faculty of BiologySaint Petersburg State UniversitySaint Petersburg199034Russia
| | - Andreas Wanninger
- Department of Evolutionary Biology, Integrative Zoology, Faculty of Life SciencesUniversity of ViennaVienna1090Austria
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12
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Abstract
Much recent marine research has been directed towards understanding the effects of anthropogenic-induced environmental change on marine biodiversity, particularly for those animals with heavily calcified exoskeletons, such as corals, molluscs and urchins. This is because life in our oceans is becoming more challenging for these animals with changes in temperature, pH and salinity. In the future, it will be more energetically expensive to make marine skeletons and the increasingly corrosive conditions in seawater are expected to result in the dissolution of these external skeletons. However, initial predictions of wide-scale sensitivity are changing as we understand more about the mechanisms underpinning skeletal production (biomineralization). These studies demonstrate the complexity of calcification pathways and the cellular responses of animals to these altered conditions. Factors including parental conditioning, phenotypic plasticity and epigenetics can significantly impact the production of skeletons and thus future population success. This understanding is paralleled by an increase in our knowledge of the genes and proteins involved in biomineralization, particularly in some phyla, such as urchins, molluscs and corals. This Review will provide a broad overview of our current understanding of the factors affecting skeletal production in marine invertebrates. It will focus on the molecular mechanisms underpinning biomineralization and how knowledge of these processes affects experimental design and our ability to predict responses to climate change. Understanding marine biomineralization has many tangible benefits in our changing world, including improvements in conservation and aquaculture and exploitation of natural calcified structure design using biomimicry approaches that are aimed at producing novel biocomposites.
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Affiliation(s)
- Melody S Clark
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
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13
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Domenici P, Seebacher F. The impacts of climate change on the biomechanics of animals: Themed Issue Article: Biomechanics and Climate Change. CONSERVATION PHYSIOLOGY 2020; 8:coz102. [PMID: 31976075 PMCID: PMC6956782 DOI: 10.1093/conphys/coz102] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 10/24/2019] [Accepted: 11/03/2019] [Indexed: 05/09/2023]
Abstract
Anthropogenic climate change induces unprecedented variability in a broad range of environmental parameters. These changes will impact material properties and animal biomechanics, thereby affecting animal performance and persistence of populations. Climate change implies warming at the global level, and it may be accompanied by altered wind speeds, wave action, ocean circulation, acidification as well as increased frequency of hypoxic events. Together, these environmental drivers affect muscle function and neural control and thereby movement of animals such as bird migration and schooling behaviour of fish. Altered environmental conditions will also modify material properties of animals. For example, ocean acidification, particularly when coupled with increased temperatures, compromises calcified shells and skeletons of marine invertebrates and byssal threads of mussels. These biomechanical consequences can lead to population declines and disintegration of habitats. Integrating biomechanical research with ecology is instrumental in predicting the future responses of natural systems to climate change and the consequences for ecosystem services such as fisheries and ecotourism.
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Affiliation(s)
- Paolo Domenici
- IAS-CNR, Località Sa Mardini, Torregrande, Oristano, 09170 Italy
| | - Frank Seebacher
- School of Life and Environmental Sciences A08, University of Sydney, Sydney, NSW 2006, Australia
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14
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Jacob DE, Ruthensteiner B, Trimby P, Henry H, Martha SO, Leitner J, Otter LM, Scholz J. Architecture of Anoteropora latirostris (Bryozoa, Cheilostomata) and implications for their biomineralization. Sci Rep 2019; 9:11439. [PMID: 31391508 PMCID: PMC6685955 DOI: 10.1038/s41598-019-47848-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 07/24/2019] [Indexed: 11/09/2022] Open
Abstract
Cheilostome Bryozoa Anoteropora latirostris, a colonial marine invertebrate, constructs its skeleton from calcite and aragonite. This study presents firstly correlated multi-scale electron microscopy, micro-computed tomography, electron backscatter diffraction and NanoSIMS mapping. We show that all primary, coarse-grained platy calcitic lateral walls are covered by fine-grained fibrous aragonite. Vertical lateral walls separating autozooid chambers have aragonite only on their distal side. This type of asymmetric mineralization of lateral walls results from the vertical arrangement of the zooids at the growth margins of the colony and represents a type of biomineralization previously unknown in cheilostome bryozoans. NanoSIMS mapping across the aragonite-calcite interface indicates an organic layer between both mineral phases, likely representing an organic template for biomineralization of aragonite on the calcite layer. Analysis of crystallographic orientations show a moderately strong crystallographic preferred orientation (CPO) for calcite (7.4 times random orientation) and an overall weaker CPO for aragonite (2.4 times random orientation) with a high degree of twinning (45%) of the aragonite grains. The calculated Young's modulus for the CPO map shows a weak mechanical direction perpendicular to the colony's upper surface facilitating this organism's strategy of clonal reproduction by fragmentation along the vertical zooid walls.
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Affiliation(s)
- D E Jacob
- Department of Earth and Planetary Sciences, Macquarie University, North Ryde, NSW, 2109, Australia.
| | - B Ruthensteiner
- Zoologische Staatssammlung München, Staatliche Naturwissenschaftliche Sammlung Bayerns, Münchhausenstraße 21, 81247, München, Germany
| | - P Trimby
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, New South Wales, 2006, Australia
- Oxford Instruments Nanoanalysis, High Wycombe, UK
| | - H Henry
- Department of Earth and Planetary Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
- Australian Research Council Centre of Excellence for Core to Crust Fluid System (CCFS)/GEMOC, Macquarie University, North Ryde, Australia
| | - S O Martha
- Senckenberg Forschungsinstitute und Naturmuseen, Marine Evertebraten III, Senckenberganlage 25, Frankfurt, Germany
| | - J Leitner
- Max Planck Institute for Chemistry, Particle Chemistry, Hahn-Meitner-Weg 1, Mainz, Germany
| | - L M Otter
- Department of Earth and Planetary Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - J Scholz
- Senckenberg Forschungsinstitute und Naturmuseen, Marine Evertebraten III, Senckenberganlage 25, Frankfurt, Germany
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15
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Figuerola B, Gore DB, Johnstone G, Stark JS. Spatio-temporal variation of skeletal Mg-calcite in Antarctic marine calcifiers. PLoS One 2019; 14:e0210231. [PMID: 31063495 PMCID: PMC6504097 DOI: 10.1371/journal.pone.0210231] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 04/21/2019] [Indexed: 11/29/2022] Open
Abstract
Human driven changes such as increases in oceanic CO2, global warming, petroleum hydrocarbons and heavy metals may negatively affect the ability of marine calcifiers to build their skeletons/shells, especially in polar regions. We examine spatio-temporal variability of skeletal Mg-calcite in shallow water Antarctic marine invertebrates using bryozoan and spirorbids as models in a recruitment experiment of settlement tiles in East Antarctica. Mineralogies were determined for 754 specimens belonging to six bryozoan species (four cheilostome and two cyclostome species) and two spirorbid species from around Casey Station. Intra- and interspecific variability in wt% MgCO3 in calcite among most species was the largest source of variation overall. Therefore, the skeletal Mg-calcite in these taxa seem to be mainly biologically controlled. However, significant spatial variability was also found in wt% MgCO3 in calcite, possibly reflecting local environment variation from sources such as freshwater input and contaminated sediments. Species with high-Mg calcite skeletons (e.g. Beania erecta) could be particularly sensitive to multiple stressors under predictions for near-future global ocean chemistry changes such as increasing temperature, ocean acidification and pollution.
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Affiliation(s)
- Blanca Figuerola
- Smithsonian Tropical Research Institute (STRI), Panama City, Panama.,Biodiversity Research Institute (IrBIO), University of Barcelona, Barcelona, Catalonia, Spain
| | - Damian B Gore
- Department of Environmental Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, Australia
| | - Glenn Johnstone
- Antarctic Conservation and Management Program, Australian Antarctic Division, Hobart, Tasmania, Australia
| | - Jonathan S Stark
- Antarctic Conservation and Management Program, Australian Antarctic Division, Hobart, Tasmania, Australia
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16
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Pagès-Escolà M, Hereu B, Garrabou J, Montero-Serra I, Gori A, Gómez-Gras D, Figuerola B, Linares C. Divergent responses to warming of two common co-occurring Mediterranean bryozoans. Sci Rep 2018; 8:17455. [PMID: 30498253 PMCID: PMC6265274 DOI: 10.1038/s41598-018-36094-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 11/15/2018] [Indexed: 11/24/2022] Open
Abstract
Climate change threatens the structure and function of marine ecosystems, highlighting the importance of understanding the response of species to changing environmental conditions. However, thermal tolerance determining the vulnerability to warming of many abundant marine species is still poorly understood. In this study, we quantified in the field the effects of a temperature anomaly recorded in the Mediterranean Sea during the summer of 2015 on populations of two common sympatric bryozoans, Myriapora truncata and Pentapora fascialis. Then, we experimentally assessed their thermal tolerances in aquaria as well as different sublethal responses to warming. Differences between species were found in survival patterns in natural populations, P. fascialis showing significantly lower survival rates than M. truncata. The thermotolerance experiments supported field observations: P. fascialis started to show signs of necrosis when the temperature was raised to 25–26 °C and completely died between 28–29 °C, coinciding with the temperature when we observed first signs of necrosis in M. truncata. The results from this study reflect different responses to warming between these two co-occurring species, highlighting the importance of combining multiple approaches to assess the vulnerability of benthic species in a changing climate world.
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Affiliation(s)
- Marta Pagès-Escolà
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Institut de Recerca de la Biodiversitat (IRBIO), University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain.
| | - Bernat Hereu
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Institut de Recerca de la Biodiversitat (IRBIO), University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
| | - Joaquim Garrabou
- Institute of Marine Sciences, ICM-CSIC, Pg. Marítim de la Barceloneta 37-49, 08003, Barcelona, Spain
| | - Ignasi Montero-Serra
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Institut de Recerca de la Biodiversitat (IRBIO), University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain.,Institute of Marine Sciences, ICM-CSIC, Pg. Marítim de la Barceloneta 37-49, 08003, Barcelona, Spain
| | - Andrea Gori
- Institute of Marine Sciences, ICM-CSIC, Pg. Marítim de la Barceloneta 37-49, 08003, Barcelona, Spain
| | - Daniel Gómez-Gras
- Institute of Marine Sciences, ICM-CSIC, Pg. Marítim de la Barceloneta 37-49, 08003, Barcelona, Spain
| | - Blanca Figuerola
- Smithsonian Tropical Research Institute, P.O. Box 0843-03092, Balboa, Republic of Panama
| | - Cristina Linares
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Institut de Recerca de la Biodiversitat (IRBIO), University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
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17
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Santagata S, Ade V, Mahon AR, Wisocki PA, Halanych KM. Compositional Differences in the Habitat-Forming Bryozoan Communities of the Antarctic Shelf. Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00116] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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18
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Brown NEM, Milazzo M, Rastrick SPS, Hall-Spencer JM, Therriault TW, Harley CDG. Natural acidification changes the timing and rate of succession, alters community structure, and increases homogeneity in marine biofouling communities. GLOBAL CHANGE BIOLOGY 2018; 24:e112-e127. [PMID: 28762601 DOI: 10.1111/gcb.13856] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 07/14/2017] [Indexed: 06/07/2023]
Abstract
Ocean acidification may have far-reaching consequences for marine community and ecosystem dynamics, but its full impacts remain poorly understood due to the difficulty of manipulating pCO2 at the ecosystem level to mimic realistic fluctuations that occur on a number of different timescales. It is especially unclear how quickly communities at various stages of development respond to intermediate-scale pCO2 change and, if high pCO2 is relieved mid-succession, whether past acidification effects persist, are reversed by alleviation of pCO2 stress, or are worsened by departures from prior high pCO2 conditions to which organisms had acclimatized. Here, we used reciprocal transplant experiments along a shallow water volcanic pCO2 gradient to assess the importance of the timing and duration of high pCO2 exposure (i.e., discrete events at different stages of successional development vs. continuous exposure) on patterns of colonization and succession in a benthic fouling community. We show that succession at the acidified site was initially delayed (less community change by 8 weeks) but then caught up over the next 4 weeks. These changes in succession led to homogenization of communities maintained in or transplanted to acidified conditions, and altered community structure in ways that reflected both short- and longer-term acidification history. These community shifts are likely a result of interspecific variability in response to increased pCO2 and changes in species interactions. High pCO2 altered biofilm development, allowing serpulids to do best at the acidified site by the end of the experiment, although early (pretransplant) negative effects of pCO2 on recruitment of these worms were still detectable. The ascidians Diplosoma sp. and Botryllus sp. settled later and were more tolerant to acidification. Overall, transient and persistent acidification-driven changes in the biofouling community, via both past and more recent exposure, could have important implications for ecosystem function and food web dynamics.
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Affiliation(s)
- Norah E M Brown
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Marco Milazzo
- DiSTeM, CoNISMa, University of Palermo, Palermo, Italy
| | - Samuel P S Rastrick
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, UK
- Institute of Marine Research, Bergen, Norway
| | - Jason M Hall-Spencer
- Marine Biology and Ecology Research Centre, University of Plymouth, Plymouth, UK
- Shimoda Marine Research Centre, Tsukuba University, Tsukuba, Japan
| | | | - Christopher D G Harley
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
- Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC, Canada
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19
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Jenkins HL, Taylor PD. Ancestrular morphology in cyclostome bryozoans and the quest for phylogenetically informative skeletal characters. J NAT HIST 2017. [DOI: 10.1080/00222933.2017.1388860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Helen L. Jenkins
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, UK
- Department of Life Sciences, Natural History Museum, London, UK
| | - Paul D. Taylor
- Department of Earth Sciences, Natural History Museum, London, UK
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20
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Swezey DS, Bean JR, Hill TM, Gaylord B, Ninokawa AT, Sanford E. Plastic responses of bryozoans to ocean acidification. ACTA ACUST UNITED AC 2017; 220:4399-4409. [PMID: 28939560 DOI: 10.1242/jeb.163436] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 09/18/2017] [Indexed: 11/20/2022]
Abstract
Phenotypic plasticity has the potential to allow organisms to respond rapidly to global environmental change, but the range and effectiveness of these responses are poorly understood across taxa and growth strategies. Colonial organisms might be particularly resilient to environmental stressors, as organizational modularity and successive asexual generations can allow for distinctively flexible responses in the aggregate form. We performed laboratory experiments to examine the effects of increasing dissolved carbon dioxide (CO2) (i.e. ocean acidification) on the colonial bryozoan Celleporella cornuta sampled from two source populations within a coastal upwelling region of the northern California coast. Bryozoan colonies were remarkably plastic under these CO2 treatments. Colonies raised under high CO2 grew more quickly, investing less in reproduction and producing lighter skeletons when compared with genetically identical clones raised under current surface atmosphere CO2 values. Bryozoans held under high CO2 conditions also changed the Mg/Ca ratio of skeletal calcite and increased the expression of organic coverings in new growth, which may serve as protection against acidified water. We also observed strong differences between source populations in reproductive investment and organic covering reaction norms, consistent with adaptive responses to persistent spatial variation in local oceanographic conditions. Our results demonstrate that phenotypic plasticity and energetic trade-offs can mediate biological responses to global environmental change, and highlight the broad range of strategies available to colonial organisms.
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Affiliation(s)
- Daniel S Swezey
- Bodega Marine Laboratory, University of California, Davis, 2099 Westshore Road, Bodega Bay, CA 94923, USA
| | - Jessica R Bean
- Department of Earth and Planetary Sciences, University of California, Davis, One Shields Ave, Davis, CA 95616, USA.,University of California Museum of Paleontology, University of California, Berkeley, CA 94720-4780, USA
| | - Tessa M Hill
- Bodega Marine Laboratory, University of California, Davis, 2099 Westshore Road, Bodega Bay, CA 94923, USA.,Department of Earth and Planetary Sciences, University of California, Davis, One Shields Ave, Davis, CA 95616, USA
| | - Brian Gaylord
- Bodega Marine Laboratory, University of California, Davis, 2099 Westshore Road, Bodega Bay, CA 94923, USA.,Department of Evolution and Ecology, University of California, Davis, One Shields Ave, Davis, CA 95616, USA
| | - Aaron T Ninokawa
- Bodega Marine Laboratory, University of California, Davis, 2099 Westshore Road, Bodega Bay, CA 94923, USA
| | - Eric Sanford
- Bodega Marine Laboratory, University of California, Davis, 2099 Westshore Road, Bodega Bay, CA 94923, USA.,Department of Evolution and Ecology, University of California, Davis, One Shields Ave, Davis, CA 95616, USA
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21
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Swezey DS, Bean JR, Ninokawa AT, Hill TM, Gaylord B, Sanford E. Interactive effects of temperature, food and skeletal mineralogy mediate biological responses to ocean acidification in a widely distributed bryozoan. Proc Biol Sci 2017; 284:rspb.2016.2349. [PMID: 28424343 DOI: 10.1098/rspb.2016.2349] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 03/20/2017] [Indexed: 11/12/2022] Open
Abstract
Marine invertebrates with skeletons made of high-magnesium calcite may be especially susceptible to ocean acidification (OA) due to the elevated solubility of this form of calcium carbonate. However, skeletal composition can vary plastically within some species, and it is largely unknown how concurrent changes in multiple oceanographic parameters will interact to affect skeletal mineralogy, growth and vulnerability to future OA. We explored these interactive effects by culturing genetic clones of the bryozoan Jellyella tuberculata (formerly Membranipora tuberculata) under factorial combinations of dissolved carbon dioxide (CO2), temperature and food concentrations. High CO2 and cold temperature induced degeneration of zooids in colonies. However, colonies still maintained high growth efficiencies under these adverse conditions, indicating a compensatory trade-off whereby colonies degenerate more zooids under stress, redirecting energy to the growth and maintenance of new zooids. Low-food concentration and elevated temperatures also had interactive effects on skeletal mineralogy, resulting in skeletal calcite with higher concentrations of magnesium, which readily dissolved under high CO2 For taxa that weakly regulate skeletal magnesium concentration, skeletal dissolution may be a more widespread phenomenon than is currently documented and is a growing concern as oceans continue to warm and acidify.
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Affiliation(s)
- Daniel S Swezey
- Bodega Marine Laboratory, University of California, Davis, 2099 Westshore Road, Bodega Bay, CA 94923, USA
| | - Jessica R Bean
- Department of Earth and Planetary Sciences, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA.,Museum of Paleontology, University of California, Berkeley, CA 94720-4780, USA
| | - Aaron T Ninokawa
- Bodega Marine Laboratory, University of California, Davis, 2099 Westshore Road, Bodega Bay, CA 94923, USA
| | - Tessa M Hill
- Bodega Marine Laboratory, University of California, Davis, 2099 Westshore Road, Bodega Bay, CA 94923, USA.,Department of Earth and Planetary Sciences, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Brian Gaylord
- Bodega Marine Laboratory, University of California, Davis, 2099 Westshore Road, Bodega Bay, CA 94923, USA.,Department of Evolution and Ecology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Eric Sanford
- Bodega Marine Laboratory, University of California, Davis, 2099 Westshore Road, Bodega Bay, CA 94923, USA.,Department of Evolution and Ecology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
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22
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23
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Zhuravlev AY, Wood RA, Penny AM. Ediacaran skeletal metazoan interpreted as a lophophorate. Proc Biol Sci 2015; 282:20151860. [PMID: 26538593 PMCID: PMC4650157 DOI: 10.1098/rspb.2015.1860] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Accepted: 10/12/2015] [Indexed: 01/29/2023] Open
Abstract
While many skeletal biomineralized genera are described from Ediacaran (635-541 million years ago, Ma) strata, none have been suggested to have an affinity above the Porifera-Cnidaria metazoan grade. Here, we reinterpret the widespread terminal Ediacaran (approx. 550-541 Ma) sessile goblet-shaped Namacalathus as a triploblastic eumetazoan. Namacalathus has a stalked cup with radially symmetrical cross section, multiple lateral lumens and a central opening. We show that the skeleton of Namacalathus is composed of a calcareous foliated ultrastructure displaying regular concordant columnar inflections, with a possible inner organic-rich layer. These features point to an accretionary growth style of the skeleton and an affinity with the Lophotrochozoa, more specifically within the Lophophorata (Brachiopoda and Bryozoa). Additionally, we present evidence for asexual reproduction as expressed by regular budding in a bilateral pattern. The interpretation of Namacalathus as an Ediacaran total group lophophorate is consistent with an early radiation of the Lophophorata, as known early Cambrian representatives were sessile, mostly stalked forms, and in addition, the oldest known calcareous Brachiopoda (early Cambrian Obolellida) and Bryozoa (Ordovician Stenolaemata) possessed foliated ultrastructures.
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Affiliation(s)
- A Yu Zhuravlev
- Department of Biological Evolution, Faculty of Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow 119991, Russia
| | - R A Wood
- School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3FE, UK
| | - A M Penny
- School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3FE, UK
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24
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Taylor PD, Waeschenbach A, Smith AM, Gordon DP. In search of phylogenetic congruence between molecular and morphological data in bryozoans with extreme adult skeletal heteromorphy. SYST BIODIVERS 2015. [DOI: 10.1080/14772000.2015.1049673] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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