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Jimi N, Britayev TA, Sako M, Woo SP, Martin D. A new genus and species of nudibranch-mimicking Syllidae (Annelida, Polychaeta). Sci Rep 2024; 14:17123. [PMID: 39075131 PMCID: PMC11286968 DOI: 10.1038/s41598-024-66465-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Accepted: 07/01/2024] [Indexed: 07/31/2024] Open
Abstract
Nudibranch mollusks, which are well-known for their vivid warning coloration and effective defenses, are mimicked by diverse invertebrates to deter predation through both Müllerian and Batesian strategies. Despite extensive documentation across different taxa, mimickers have not been detected among annelids, including polychaetes, until now. This study described a new genus and species of polychaete living on Dendronephthya octocorals in Vietnam and Japan. Belonging to Syllidae, it exhibits unique morphological adaptations such as a low number of body segments, simple chaetae concealed within the parapodia and large and fusiform antennae and cirri. Moreover, these appendages are vividly colored, featuring an internal dark red area with numerous terminal white spots and bright yellow tips, effectively contributing to mimicking the appearance of a nudibranch. This discovery not only documents the first known instance of such mimicry among annelids, but also expands our understanding of evolutionary adaptation and ecological strategies in marine invertebrates.
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Affiliation(s)
- Naoto Jimi
- Sugashima Marine Biological Laboratory, Graduate School of Science, Nagoya University, 429-63 Sugashima, Toba, Mie, 517-0004, Japan.
- Centre for Marine & Coastal Studies, Universiti Sains Malaysia, USM, 11800, Penang, Malaysia.
| | - Temir A Britayev
- Laboratory of Marine Invertebrates Morphology and Ecology, A. N. Severtzov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russian Federation
| | - Misato Sako
- Sugashima Marine Biological Laboratory, Graduate School of Science, Nagoya University, 429-63 Sugashima, Toba, Mie, 517-0004, Japan
| | - Sau Pinn Woo
- Centre for Marine & Coastal Studies, Universiti Sains Malaysia, USM, 11800, Penang, Malaysia
| | - Daniel Martin
- Department of Marine Ecology, Centre d'Estudis Avançats de Blanes (CEAB-CSIC), Blanes, Catalunya, Spain
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Galià-Camps C, Araujo AK, Carmona L, Martín-Hervás MDR, Pola M, Palero F, Cervera JL. New mitogenomes of Runcinidae and Facelinidae: two understudied heterobranch families (Mollusca: Gastropoda). Mitochondrial DNA B Resour 2024; 9:771-776. [PMID: 38919811 PMCID: PMC11198154 DOI: 10.1080/23802359.2024.2363365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 05/29/2024] [Indexed: 06/27/2024] Open
Abstract
Here, we present the mitochondrial sequences of two sea slugs (Heterobranchia): Runcina aurata and Facelina auriculata, the latter being the type species of the family. The mitochondrial genomes are 14,282 and 14,171bp in length, respectively, with a complete set of 13 PCGs, 2 rRNAs, and 22 tRNAs. None of the mitogenomes show gene reorganization, keeping the standard mitogenomic structure of Heterobranchia. Nucleotide composition differs significantly between them, with R. aurata showing the most AT-rich mitogenome (25.7% GC content) reported to date in Heterobranchia, and F. auriculata showing a rich GC content (35%) compared with other heterobranch mitochondrial genomes.
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Affiliation(s)
- Carles Galià-Camps
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona (UB), Barcelona, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona (UB), Barcelona, Spain
| | - Ana Karla Araujo
- Departamento de Biología, Facultad de Ciencias del Mar y Ambientales, Campus de Excelencia Internacional del Mar (CEIMAR), Universidad de Cádiz, Puerto Real, Spain
- Instituto Universitario de Investigación Marina (INMAR), Universidad de Cádiz, Puerto Real, Spain
| | - Leila Carmona
- Departamento de Biología, Facultad de Ciencias del Mar y Ambientales, Campus de Excelencia Internacional del Mar (CEIMAR), Universidad de Cádiz, Puerto Real, Spain
- Instituto Universitario de Investigación Marina (INMAR), Universidad de Cádiz, Puerto Real, Spain
| | - María del Rosario Martín-Hervás
- Departamento de Biología, Facultad de Ciencias del Mar y Ambientales, Campus de Excelencia Internacional del Mar (CEIMAR), Universidad de Cádiz, Puerto Real, Spain
- Instituto Universitario de Investigación Marina (INMAR), Universidad de Cádiz, Puerto Real, Spain
| | - Marta Pola
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, CSIC, Madrid, Spain
- Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM), CSIC, Madrid, Spain
| | - Ferran Palero
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Paterna, Spain
- Department of Life Sciences, The Natural History Museum, London, UK
| | - Juan Lucas Cervera
- Departamento de Biología, Facultad de Ciencias del Mar y Ambientales, Campus de Excelencia Internacional del Mar (CEIMAR), Universidad de Cádiz, Puerto Real, Spain
- Instituto Universitario de Investigación Marina (INMAR), Universidad de Cádiz, Puerto Real, Spain
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Yiu SKF, Leung TK, Lee GY, Yan M. Morphology and Phylogenetic Position of the Sargassum Nudibranch Scyllaea fulva Quoy & Gaimard, 1824 (Nudibranchia: Scyllaeidae): First Record in Hong Kong. Zool Stud 2024; 62:e4. [PMID: 39355317 PMCID: PMC11443427 DOI: 10.6620/zs.2024.63-04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 12/27/2023] [Indexed: 10/03/2024]
Abstract
Scyllaeidae is a small group of nudibranchs comprising three genera (Scyllaea, Notobryon, and Crosslandia) with striking morphological similarities, making their identification challenging based on external features alone. Previous studies have highlighted the significance of central radular teeth in distinguishing Notobryon from Scyllaea and Crosslandia. The genus Scyllaea, commonly known as the sargassum nudibranch, currently consists of only two valid species, Scyllaea pelagica and Scyllaea fulva. These species inhabit seaweed Sargassum spp., feeding on hydroids. During a biodiversity survey conducted in April 2023, seven sargassum nudibranch individuals were collected from the seaweed Sargassum spp. at a depth of 2 meters in Tai She Wan through SCUBA diving. Initially, the specimens were misidentified based on their resemblance to Notobryon wardi and previous local records. However, thorough morphological and molecular examinations confirmed them to be Scyllaea fulva, representing the first record of this species in Hong Kong. Notably, our specimens lacked the blue spots observed in specimens from Thailand and the West Pacific Ocean, as reported in previous studies. Internally, a pineapple-like structure formed a honeycomb pattern on the surface of the masticatory edge of the jaw flap, with the presence of central radular teeth. A Maximum Likelihood tree analysis revealed Crosslandia to be the sister group of Scyllaea. Comparative analysis of intra-specific distances between individuals from the Philippines, French Polynesia, and Hong Kong indicated a close relationship between the Hong Kong specimens and those from the Philippines. Furthermore, we provide a detailed description of the external and internal morphology of Scyllaea fulva in this paper, integrating valuable morphological information for future species identification purposes.
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Affiliation(s)
- Sam King Fung Yiu
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China. E-mail: (Yiu)
- State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China. E-mail: (Yan) ; (Leung); (Lee)
| | - Thomas Ka Leung
- State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China. E-mail: (Yan) ; (Leung); (Lee)
| | - Gabriel Yeung Lee
- State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China. E-mail: (Yan) ; (Leung); (Lee)
| | - Meng Yan
- State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China. E-mail: (Yan) ; (Leung); (Lee)
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4
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Goodheart JA, Rio RA, Taraporevala NF, Fiorenza RA, Barnes SR, Morrill K, Jacob MAC, Whitesel C, Masterson P, Batzel GO, Johnston HT, Ramirez MD, Katz PS, Lyons DC. A chromosome-level genome for the nudibranch gastropod Berghia stephanieae helps parse clade-specific gene expression in novel and conserved phenotypes. BMC Biol 2024; 22:9. [PMID: 38233809 PMCID: PMC10795318 DOI: 10.1186/s12915-024-01814-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 01/03/2024] [Indexed: 01/19/2024] Open
Abstract
BACKGROUND How novel phenotypes originate from conserved genes, processes, and tissues remains a major question in biology. Research that sets out to answer this question often focuses on the conserved genes and processes involved, an approach that explicitly excludes the impact of genetic elements that may be classified as clade-specific, even though many of these genes are known to be important for many novel, or clade-restricted, phenotypes. This is especially true for understudied phyla such as mollusks, where limited genomic and functional biology resources for members of this phylum have long hindered assessments of genetic homology and function. To address this gap, we constructed a chromosome-level genome for the gastropod Berghia stephanieae (Valdés, 2005) to investigate the expression of clade-specific genes across both novel and conserved tissue types in this species. RESULTS The final assembled and filtered Berghia genome is comparable to other high-quality mollusk genomes in terms of size (1.05 Gb) and number of predicted genes (24,960 genes) and is highly contiguous. The proportion of upregulated, clade-specific genes varied across tissues, but with no clear trend between the proportion of clade-specific genes and the novelty of the tissue. However, more complex tissue like the brain had the highest total number of upregulated, clade-specific genes, though the ratio of upregulated clade-specific genes to the total number of upregulated genes was low. CONCLUSIONS Our results, when combined with previous research on the impact of novel genes on phenotypic evolution, highlight the fact that the complexity of the novel tissue or behavior, the type of novelty, and the developmental timing of evolutionary modifications will all influence how novel and conserved genes interact to generate diversity.
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Affiliation(s)
- Jessica A Goodheart
- Division of Invertebrate Zoology, American Museum of Natural History, New York, NY, USA.
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA.
| | - Robin A Rio
- Bioengineering Department, Stanford University, Stanford, CA, USA
| | - Neville F Taraporevala
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
- Department of Wildland Resources, Utah State University, Logan, UT, USA
| | - Rose A Fiorenza
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Seth R Barnes
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Kevin Morrill
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Mark Allan C Jacob
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Carl Whitesel
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Park Masterson
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Grant O Batzel
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Hereroa T Johnston
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - M Desmond Ramirez
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, USA
- Institute of Neuroscience, University of Oregon, Eugene, OR, USA
| | - Paul S Katz
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Deirdre C Lyons
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA.
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5
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Goodheart JA, Rio RA, Taraporevala NF, Fiorenza RA, Barnes SR, Morrill K, Jacob MAC, Whitesel C, Masterson P, Batzel GO, Johnston HT, Ramirez MD, Katz PS, Lyons DC. A chromosome-level genome for the nudibranch gastropod Berghia stephanieae helps parse clade-specific gene expression in novel and conserved phenotypes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.04.552006. [PMID: 38014205 PMCID: PMC10680569 DOI: 10.1101/2023.08.04.552006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
How novel phenotypes originate from conserved genes, processes, and tissues remains a major question in biology. Research that sets out to answer this question often focuses on the conserved genes and processes involved, an approach that explicitly excludes the impact of genetic elements that may be classified as clade-specific, even though many of these genes are known to be important for many novel, or clade-restricted, phenotypes. This is especially true for understudied phyla such as mollusks, where limited genomic and functional biology resources for members of this phylum has long hindered assessments of genetic homology and function. To address this gap, we constructed a chromosome-level genome for the gastropod Berghia stephanieae (Valdés, 2005) to investigate the expression of clade-specific genes across both novel and conserved tissue types in this species. The final assembled and filtered Berghia genome is comparable to other high quality mollusk genomes in terms of size (1.05 Gb) and number of predicted genes (24,960 genes), and is highly contiguous. The proportion of upregulated, clade-specific genes varied across tissues, but with no clear trend between the proportion of clade-specific genes and the novelty of the tissue. However, more complex tissue like the brain had the highest total number of upregulated, clade-specific genes, though the ratio of upregulated clade-specific genes to the total number of upregulated genes was low. Our results, when combined with previous research on the impact of novel genes on phenotypic evolution, highlight the fact that the complexity of the novel tissue or behavior, the type of novelty, and the developmental timing of evolutionary modifications will all influence how novel and conserved genes interact to generate diversity.
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Affiliation(s)
- Jessica A. Goodheart
- Division of Invertebrate Zoology, American Museum of Natural History, New York, NY USA
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Robin A. Rio
- Bioengineering Department, Stanford University, Stanford, CA, USA
| | - Neville F. Taraporevala
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
- Department of Wildland Resources, Utah State University, Logan, UT, USA
| | - Rose A. Fiorenza
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Seth R. Barnes
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Kevin Morrill
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Mark Allan C. Jacob
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Carl Whitesel
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Park Masterson
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Grant O. Batzel
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Hereroa T. Johnston
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - M. Desmond Ramirez
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Paul S. Katz
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Deirdre C. Lyons
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
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First Record of Corallivorous Nudibranch Pinufius (Gastropoda: Nudibranchia) in the South China Sea: A Suspected New Species of Pinufius. DIVERSITY 2023. [DOI: 10.3390/d15020226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
A corallivorous nudibranch from the South China Sea reproduced explosively and caused extensive damage to Porites in our aquarium. In this study, morphological and molecular analyses of the nudibranch were conducted and described. Morphologically, this nudibranch was nearly consistent with Pinufius rebus in its characteristics intermediate between arminids and aeolids. The only detected difference was that the hook-like denticles on the masticatory border of P. rebus were absent in this nudibranch. In a molecular analysis, phylogenetic results based on the cytochrome oxidase subunit-I, 16S rRNA, and histone H3 gene sequences showed that this nudibranch and P. rebus form a well-supported sister clade under the superfamily Fionoidea, with significant interspecific divergence (0.18). Thus, we presumed that this nudibranch is a new species of Pinufius. Our results extend the distribution of Pinufius to the South China Sea, support the current taxonomic status of Pinufius under the superfamily Fionoidea, and imply that the species composition of Pinufius is more complex than previous records. Moreover, as a corallivorous nudibranch, the potential threat of Pinufius to coral health cannot be neglected.
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Vorobyeva OA, Ekimova IA, Malakhov VV. Morphological Organization of Cerata in the Nudibranch Pteraeolidia semperi (Gastropoda, Nudibranchia). DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2023; 508:72-75. [PMID: 37186050 DOI: 10.1134/s0012496622700181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/05/2022] [Accepted: 10/06/2022] [Indexed: 05/17/2023]
Abstract
The morphology of cerata and cnidosacs were studied in the nudibranch mollusk Pteraeolidia semperi (Bergh, 1870). Fine tubules arise from the gastrodermal channel of the digestive gland and contain cells with symbiotic algae (zooxanthellae). The cnidosac stores large kleptocnides. Thus, P. semperi provides a unique example of symbiotrophic feeding specialization. Morphological organization of its cerata and the digestive gland demonstrates several adaptations for housing zooxanthellae and providing them with proper conditions for active photosynthesis.
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Ekimova IA, Vorobyeva OA, Mikhlina AL, Schepetov DM, Vortsepneva EV, Antokhina TI, Malakhov VV. Nematocyst sequestration within the family Fionidae (Gastropoda: Nudibranchia) considering ecological properties and evolution. Front Zool 2022; 19:29. [PMID: 36384570 PMCID: PMC9670572 DOI: 10.1186/s12983-022-00474-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 11/03/2022] [Indexed: 11/17/2022] Open
Abstract
Aeolid nudibranchs are well-known for their ability to incorporate cnidarian nematocysts and use them for defense; this process is tightly linked with the feeding preferences of molluscs. As many nudibranch groups show signs of ecology-based adaptive radiation, studies of prey-based defensive mechanisms can provide valuable insight into details of nudibranch evolutionary history. The main goal of this study is to test the correlation of ecological traits, feeding mechanisms, and prey preferences with cnidosac fine morphology and to pinpoint the phylogenetic value of these traits. We study the cnidosac morphology in thirteen species—representatives of the main lineages within the family Fionidae s.l. The morphological analysis includes histological sections, transmission electron microscopy, confocal laser scanning microscopy, and scanning electron microscopy. For phylogenetic study, available molecular data from public repositories were used, and phylogenetic trees were produced based on Bayesian Inference and Maximum likelihood analysis for a concatenated dataset of three molecular markers (COI, 16S, H3). In general, fionid cnidosacs fit the common aeolid pattern, but among different species we detected a high variation in type of obtained nematocysts, their arrangement within cnidophages, and in number of cell types within cnidosacs. We report on presence of cellules speciale in the haemocoel of all studied species, and for the first time, we report on cells with chitinous spindles in the haemocoel of all fionids except Eubranchus. The function of both these cell types remains unknown. The loss of functional cnidosacs occurred at least three times within Fionidae, and in case of the genera Phestilla, Calma, and Fiona, this loss is linked to their non-cnidarian diet. The diversity of cnidosac fine structure within Fionidae s.l. correlates with that of the radular morphology and feeding preferences of each species. Prey shifts between cnidarian and non-cnidarian prey (both through evolutionary shifts and individual variation) rarely occur within Fionidae s.l.; however, microevolutionary shifts between different hydrozoan species within a single genus are more common. Cnidosac morphology demonstrates considerable resulting changes even when switching between similar hydrozoan species, or changing the feeding site on same prey species. These data indicate that cnidosac morphology likely follows microevolutionary prey shifts—in other words, it is affected by switches in prey species and changes in feeding sites with a single prey species. Thus, the cnidosac morphology may be a useful indicator when studying ecological features of particular species.
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Taraporevala NF, Lesoway MP, Goodheart JA, Lyons DC. Precocious Sperm Exchange in the Simultaneously Hermaphroditic Nudibranch, Berghia stephanieae. Integr Org Biol 2022; 4:obac030. [PMID: 36089995 PMCID: PMC9449679 DOI: 10.1093/iob/obac034] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 06/10/2022] [Accepted: 07/28/2022] [Indexed: 11/15/2022] Open
Abstract
Sexual systems vary greatly across molluscs. This diversity includes simultaneous hermaphroditism, with both sexes functional at the same time. Most nudibranch molluscs are thought to be simultaneous hermaphrodites, but detailed studies of reproductive development and timing remain rare as most species cannot be cultured in the lab. The aeolid nudibranch, Berghia stephanieae, is one such species that can be cultured through multiple generations on the benchtop. We studied B. stephanieae reproductive timing to establish when animals first exchange sperm and how long sperm can be stored. We isolated age- and size-matched individuals at sequential timepoints to learn how early individuals can exchange sperm. Individuals isolated at 10 weeks post initial feeding (wpf; ∼13 weeks postlaying [wpl]) can produce fertilized eggs. This is 6 weeks before animals first lay egg masses, indicating that sperm exchange occurs well before individuals are capable of laying eggs. Our results indicate that male gonads become functional for animals between 6 mm (∼6 wpf, ∼9 wpl) and 9 mm (∼12 wpf, ∼15 wpl) in length. That is much smaller (and sooner) than the size (and age) of individuals at first laying (12–19 mm; ∼16 wpf, ∼19 wpl), indicating that male and female functions do not develop simultaneously. We also tracked the number of fertilized eggs in each egg mass, which remained steady for the first 10–15 egg masses, followed by a decline to near-to-no fertilization. This dataset provides insights into the precise timing of the onset of functionality of the male and female reproductive systems in B. stephanieae. These data contribute to a broader understanding of reproductive development and the potential for understanding the evolution of diverse sexual systems in molluscs.
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Affiliation(s)
- Neville F Taraporevala
- Scripps Institution of Oceanography, University of California San Diego , 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Maryna P Lesoway
- Scripps Institution of Oceanography, University of California San Diego , 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Jessica A Goodheart
- Scripps Institution of Oceanography, University of California San Diego , 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Deirdre C Lyons
- Scripps Institution of Oceanography, University of California San Diego , 9500 Gilman Drive, La Jolla, CA 92093, USA
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Furfaro G, D'Elia M, Mariano S, Trainito E, Solca M, Piraino S, Belmonte G. SEM/EDX analysis of stomach contents of a sea slug snacking on a polluted seafloor reveal microplastics as a component of its diet. Sci Rep 2022; 12:10244. [PMID: 35715497 PMCID: PMC9206003 DOI: 10.1038/s41598-022-14299-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 06/03/2022] [Indexed: 11/18/2022] Open
Abstract
Understanding the impacts of microplastics on living organisms in aquatic habitats is one of the hottest research topics worldwide. Despite increased attention, investigating microplastics in underwater environments remains a problematic task, due to the ubiquitous occurrence of microplastic, its multiple modes of interactions with the biota, and to the diversity of the synthetic organic polymers composing microplastics in the field. Several studies on microplastics focused on marine invertebrates, but to date, the benthic sea slugs (Mollusca, Gastropoda, Heterobranchia) were not yet investigated. Sea slugs are known to live on the organisms on which they feed on or to snack while gliding over the sea floor, but also as users of exogenous molecules or materials not only for nutrition. Therefore, they may represent a potential biological model to explore new modes of transformation and/or management of plastic, so far considered to be a non-biodegradable polymer. In this study we analysed the stomachal content of Bursatella leachii, an aplysiid heterobranch living in the Mar Piccolo, a highly polluted coastal basin near Taranto, in the northern part of the Ionian Sea. Microplastics were found in the stomachs of all the six sampled specimens, and SEM/EDX analyses were carried out to characterize the plastic debris. The SEM images and EDX spectra gathered here should be regarded as a baseline reference database for future investigations on marine Heterobranchia and their interactions with microplastics.
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Affiliation(s)
- Giulia Furfaro
- Department of Biological and Environmental Sciences and Technologies - DiSTeBA, University of Salento, Via Prov.le Lecce-Monteroni, 73100, Lecce, Italy.
| | - Marcella D'Elia
- Department of Mathematics and Physics "Ennio de Giorgi", University of Salento, Via Prov.Le Lecce-Monteroni, 73100, Lecce, Italy
| | - Stefania Mariano
- Department of Biological and Environmental Sciences and Technologies - DiSTeBA, University of Salento, Via Prov.le Lecce-Monteroni, 73100, Lecce, Italy
| | - Egidio Trainito
- Marine Protected Area 'Tavolara-Punta Coda Cavallo', Olbia, Italy
| | - Michele Solca
- Museo di Biologia Marina "Pietro Parenzan", Via Vespucci 13/17, Porto Cesareo, 73010, Lecce, Italy
| | - Stefano Piraino
- Department of Biological and Environmental Sciences and Technologies - DiSTeBA, University of Salento, Via Prov.le Lecce-Monteroni, 73100, Lecce, Italy.,Museo di Biologia Marina "Pietro Parenzan", Via Vespucci 13/17, Porto Cesareo, 73010, Lecce, Italy.,Consorzio Nazionale Interuniversitario per le Scienze del Mare (CoNISMa), P.le Flaminio 9, 00198, Rome, Italy
| | - Genuario Belmonte
- Department of Biological and Environmental Sciences and Technologies - DiSTeBA, University of Salento, Via Prov.le Lecce-Monteroni, 73100, Lecce, Italy.,Museo di Biologia Marina "Pietro Parenzan", Via Vespucci 13/17, Porto Cesareo, 73010, Lecce, Italy.,Consorzio Nazionale Interuniversitario per le Scienze del Mare (CoNISMa), P.le Flaminio 9, 00198, Rome, Italy
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11
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Rosani U. Tracing RNA viruses associated with Nudibranchia gastropods. PeerJ 2022; 10:e13410. [PMID: 35586129 PMCID: PMC9109684 DOI: 10.7717/peerj.13410] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 04/19/2022] [Indexed: 01/14/2023] Open
Abstract
Background Nudibranchia is an under-studied taxonomic group of gastropods, including more than 3,000 species with colourful and extravagant body shapes and peculiar predatory and defensive strategies. Although symbiosis with bacteria has been reported, no data are available for the nudibranch microbiome nor regarding viruses possibly associated with these geographically widespread species. Methods Based on 47 available RNA sequencing datasets including more than two billion reads of 35 nudibranch species, a meta-transcriptome assembly was constructed. Taxonomic searches with DIAMOND, RNA-dependent-RNA-polymerase identification with palmscan and viral hallmark genes identification by VirSorter2 in combination with CheckV were applied to identify genuine viral genomes, which were then annotated using CAT. Results A total of 20 viral genomes were identified as bona fide viruses, among 552 putative viral contigs resembling both RNA viruses of the Negarnaviricota, Pisuviricota, Kitrinoviricota phyla and actively transcribing DNA viruses of the Cossaviricota and Nucleocytoviricota phyla. The 20 commonly identified viruses showed similarity with RNA viruses identified in other RNA-seq experiments and can be putatively associated with bacteria, plant and arthropod hosts by co-occurence analysis. The RNA samples having the highest viral abundances showed a heterogenous and mostly sample-specific distribution of the identified viruses, suggesting that nudibranchs possess diversified and mostly unknown viral communities.
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Goodheart JA, Barone V, Lyons DC. Movement and storage of nematocysts across development in the nudibranch Berghia stephanieae (Valdés, 2005). Front Zool 2022; 19:16. [PMID: 35436919 PMCID: PMC9016961 DOI: 10.1186/s12983-022-00460-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 03/31/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Intracellular sequestration requires specialized cellular and molecular mechanisms allowing a predator to retain and use specific organelles that once belonged to its prey. Little is known about how common cellular mechanisms, like phagocytosis, can be modified to selectively internalize and store foreign structures. One form of defensive sequestration involves animals that sequester stinging organelles (nematocysts) from their cnidarian prey. While it has been hypothesized that nematocysts are identified by specialized phagocytic cells for internalization and storage, little is known about the cellular and developmental mechanisms of this process in any metazoan lineage. This knowledge gap is mainly due to a lack of genetically tractable model systems among predators and their cnidarian prey. RESULTS Here, we introduce the nudibranch Berghia stephanieae as a model system to investigate the cell, developmental, and physiological features of nematocyst sequestration selectivity. We first show that B. stephanieae, which feeds on Exaiptasia diaphana, selectively sequesters nematocysts over other E. diaphana tissues found in their digestive gland. Using confocal microscopy, we document that nematocyst sequestration begins shortly after feeding and prior to the formation of the appendages (cerata) where the organ responsible for sequestration (the cnidosac) resides in adults. This finding is inconsistent with previous studies that place the formation of the cnidosac after cerata emerge. Our results also show, via live imaging assays, that both nematocysts and dinoflagellates can enter the nascent cnidosac structure. This result indicates that selectivity for nematocysts occurs inside the cnidosac in B. stephanieae, likely in the cnidophage cells themselves. CONCLUSIONS Our work highlights the utility of B. stephanieae for future research, because: (1) this species can be cultured in the laboratory, which provides access to all developmental stages, and (2) the transparency of early juveniles makes imaging techniques (and therefore cell and molecular assays) feasible. Our results pave the way for future studies using live imaging and targeted gene editing to identify the molecular mechanisms involved in nematocyst sequestration. Further studies of nematocyst sequestration in B. stephanieae will also allow us to investigate how common cellular mechanisms like phagocytosis can be modified to selectively internalize and store foreign structures.
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Affiliation(s)
- Jessica A Goodheart
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, 92037, USA.
| | - Vanessa Barone
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, 92037, USA
| | - Deirdre C Lyons
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, 92037, USA
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Maroni PJ, Baker BJ, Moran AL, Woods HA, Avila C, Johnstone GJ, Stark JS, Kocot KM, Lockhart S, Saucède T, Rouse GW, Wilson NG. One Antarctic slug to confuse them all: the underestimated diversity of Doris kerguelenensis. INVERTEBR SYST 2022. [DOI: 10.1071/is21073] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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14
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Karmeinski D, Meusemann K, Goodheart JA, Schroedl M, Martynov A, Korshunova T, Wägele H, Donath A. Transcriptomics provides a robust framework for the relationships of the major clades of cladobranch sea slugs (Mollusca, Gastropoda, Heterobranchia), but fails to resolve the position of the enigmatic genus Embletonia. BMC Ecol Evol 2021; 21:226. [PMID: 34963462 PMCID: PMC8895541 DOI: 10.1186/s12862-021-01944-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/23/2021] [Indexed: 11/24/2022] Open
Abstract
Background The soft-bodied cladobranch sea slugs represent roughly half of the biodiversity of marine nudibranch molluscs on the planet. Despite their global distribution from shallow waters to the deep sea, from tropical into polar seas, and their important role in marine ecosystems and for humans (as targets for drug discovery), the evolutionary history of cladobranch sea slugs is not yet fully understood. Results To enlarge the current knowledge on the phylogenetic relationships, we generated new transcriptome data for 19 species of cladobranch sea slugs and two additional outgroup taxa (Berthella plumula and Polycera quadrilineata). We complemented our taxon sampling with previously published transcriptome data, resulting in a final data set covering 56 species from all but one accepted cladobranch superfamilies. We assembled all transcriptomes using six different assemblers, selecting those assemblies that provided the largest amount of potentially phylogenetically informative sites. Quality-driven compilation of data sets resulted in four different supermatrices: two with full coverage of genes per species (446 and 335 single-copy protein-coding genes, respectively) and two with a less stringent coverage (667 genes with 98.9% partition coverage and 1767 genes with 86% partition coverage, respectively). We used these supermatrices to infer statistically robust maximum-likelihood trees. All analyses, irrespective of the data set, indicate maximal statistical support for all major splits and phylogenetic relationships at the family level. Besides the questionable position of Noumeaella rubrofasciata, rendering the Facelinidae as polyphyletic, the only notable discordance between the inferred trees is the position of Embletonia pulchra. Extensive testing using Four-cluster Likelihood Mapping, Approximately Unbiased tests, and Quartet Scores revealed that its position is not due to any informative phylogenetic signal, but caused by confounding signal. Conclusions Our data matrices and the inferred trees can serve as a solid foundation for future work on the taxonomy and evolutionary history of Cladobranchia. The placement of E. pulchra, however, proves challenging, even with large data sets and various optimization strategies. Moreover, quartet mapping results show that confounding signal present in the data is sufficient to explain the inferred position of E. pulchra, again leaving its phylogenetic position as an enigma. Supplementary Information The online version contains supplementary material available at 10.1186/s12862-021-01944-0.
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Affiliation(s)
- Dario Karmeinski
- Centre for Molecular Biodiversity Research, Leibniz Institute for the Analysis of Biodiversity Change/ZFMK, Museum Koenig, Adenauerallee 160, 53113, Bonn, Germany
| | - Karen Meusemann
- Leibniz Institute for the Analysis of Biodiversity Change/ZFMK, Museum Koenig, Adenauerallee 160, 53113, Bonn, Germany.,Australian National Insect Collection, National Research Collections Australia, Commonwealth Scientific and Industrial Research Organisation (CSIRO), National Facilities and Collections, Clunies Ross Street, Acton, Canberra, ACT, 2601, Australia
| | - Jessica A Goodheart
- Scripps Institution of Oceanography, University of California, La Jolla, San Diego, CA, 92037, USA
| | - Michael Schroedl
- SNSB-Bavarian State Collection of Zoology, Münchhausenstr. 21, 81247, Munich, Germany.,GeoBioCenter LMU und Biozentrum, Ludwig-Maximilians-Universität München, Großhaderner Str. 2, 82152, Planegg-Martinsried, Germany
| | - Alexander Martynov
- Zoological Museum of the Moscow State University, Bolshaya Nikitskaya Str. 6, 125009, Moscow, Russia
| | - Tatiana Korshunova
- Koltzov Institute of Developmental Biology, Vavilova Str. 26, 119334, Moscow, Russia
| | - Heike Wägele
- Centre for Molecular Biodiversity Research, Leibniz Institute for the Analysis of Biodiversity Change/ZFMK, Museum Koenig, Adenauerallee 160, 53113, Bonn, Germany
| | - Alexander Donath
- Centre for Molecular Biodiversity Research, Leibniz Institute for the Analysis of Biodiversity Change/ZFMK, Museum Koenig, Adenauerallee 160, 53113, Bonn, Germany.
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Furfaro G, Mariottini P. Looking at the Nudibranch Family Myrrhinidae (Gastropoda, Heterobranchia) from a Mitochondrial '2D Folding Structure' Point of View. Life (Basel) 2021; 11:583. [PMID: 34207329 PMCID: PMC8235141 DOI: 10.3390/life11060583] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 06/14/2021] [Accepted: 06/17/2021] [Indexed: 01/16/2023] Open
Abstract
Integrative taxonomy is an evolving field of multidisciplinary studies often utilised to elucidate phylogenetic reconstructions that were poorly understood in the past. The systematics of many taxa have been resolved by combining data from different research approaches, i.e., molecular, ecological, behavioural, morphological and chemical. Regarding molecular analysis, there is currently a search for new genetic markers that could be diagnostic at different taxonomic levels and that can be added to the canonical ones. In marine Heterobranchia, the most widely used mitochondrial markers, COI and 16S, are usually analysed by comparing the primary sequence. The 16S rRNA molecule can be folded into a 2D secondary structure that has been poorly exploited in the past study of heterobranchs, despite 2D molecular analyses being sources of possible diagnostic characters. Comparison of the results from the phylogenetic analyses of a concatenated (the nuclear H3 and the mitochondrial COI and 16S markers) dataset (including 30 species belonging to eight accepted genera) and from the 2D folding structure analyses of the 16S rRNA from the type species of the genera investigated demonstrated the diagnostic power of this RNA molecule to reveal the systematics of four genera belonging to the family Myrrhinidae (Gastropoda, Heterobranchia). The "molecular morphological" approach to the 16S rRNA revealed to be a powerful tool to delimit at both species and genus taxonomic levels and to be a useful way of recovering information that is usually lost in phylogenetic analyses. While the validity of the genera Godiva, Hermissenda and Phyllodesmium are confirmed, a new genus is necessary and introduced for Dondice banyulensis, Nemesis gen. nov. and the monospecific genus Nanuca is here synonymised with Dondice, with Nanuca sebastiani transferred into Dondice as Dondice sebastiani comb. nov.
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Affiliation(s)
- Giulia Furfaro
- Department of Biological and Environmental Sciences and Technologies—DiSTeBA, University of Salento, I-73100 Lecce, Italy
| | - Paolo Mariottini
- Department of Science, University of Roma Tre, I-00146 Rome, Italy;
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Vorobyeva OA, Malakhov VV, Ekimova IA. General and fine structure of Aeolidia papillosa cnidosacs (Gastropoda: Nudibranchia). J Morphol 2021; 282:754-768. [PMID: 33713032 DOI: 10.1002/jmor.21346] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 03/06/2021] [Accepted: 03/08/2021] [Indexed: 11/09/2022]
Abstract
Nudibranch mollusks (Gastropoda: Heterobranchia) are widely known for their ability to incorporate some active biochemical compounds of their prey, or even organelles and symbionts of the prey, which assured biological success of this group. At the same time, the process of nematocysts obtaining and incorporation into specific structures called cnidosacs by cladobranch mollusks remain poorly studied. This highlights a necessity of additional ultrastructural studies of cnidosac and adjacent organs in various aeolid mollusks using modern microscopic methods as they may provide new insight into the cnidosac diversity and fine-scale dynamics of nematocysts sequestration process. The present study is focused on the general and fine structure of the cnidosac area in cladobranch Aeolidia papillosa (Aeolidiidae). Specific goals of our study were to provide a detailed description of histological and ultrafine structure of epidermis, upper parts of the digestive glands and the cnidosac, its innervation and proliferation using standard histological techniques, confocal laser scanning microscopy (CLSM) and transmission electron microscopy. Our results clearly demonstrated that A. papillosa cnidosac is a much more complex structure, than it was thought, especially compared with simple cnidosacs found in flabellinids and facelinids. Using CLSM for functional morphological analysis provides a better resolution in visualization of structural elements within a cnidosac compared with traditional histological techniques. We revealed the presence of two cell types in the cnidophage zone: cnidophages and interstitial cells, which differ in ultrastructure and function. Our results also document the presence of a specific cnidopore zone, lined with differentiated cuboid epithelium bearing long microvilli, which likely provides a unidirectional flow of nematocysts during kleptocnides extrusion. For the first time, occurrence of vacuoles containing protective chitinous spindles in the cnidosac epithelium was shown.
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Affiliation(s)
- Olga A Vorobyeva
- Invertebrate Zoology Department, Lomonosov Moscow State University, Moscow, Russia
| | - Vladimir V Malakhov
- Invertebrate Zoology Department, Lomonosov Moscow State University, Moscow, Russia
| | - Irina A Ekimova
- Invertebrate Zoology Department, Lomonosov Moscow State University, Moscow, Russia
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17
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Paz-Sedano S, Candás M, Gosliner TM, Pola M. Undressing Lophodoris danielsseni (Friele & Hansen, 1878) (Nudibranchia: Goniodorididae). ORG DIVERS EVOL 2021. [DOI: 10.1007/s13127-020-00470-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Anthony S. Cnida sequestration in aeolid nudibranchs: variability and retention time of sequestered cnidae in the opalescent sea slug, Hermissenda crassicornis (Gastropoda, Nudibranchia). CAN J ZOOL 2020. [DOI: 10.1139/cjz-2020-0010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Aeolid sea slugs can isolate and store stinging cnidae obtained from their cnidarian prey, presumably for their own defence. There are 30 different varieties of cnidae, identified by their unique structure. The aeolids engulf the cnidae and store them in a functional state at the tips of their cerata. Although the process of cnida sequestration is reasonably well understood in aeolids, two critical questions remain: (1) are cnida types uniformly distributed among the cerata and (2) how long do sequestered cnidae persist? I collected opalescent sea slugs (Hermissenda crassicornis (Eschscholtz, 1831)) from Barkley Sound, British Columbia, Canada, and determined the cnida complements in four cerata per individual by microscope. The cnida complements differed between cerata from different body regions within the individual (values of Whittaker’s dissimilarity index from 2.5% to 36.3%). Furthermore, the cnidae varieties in low abundances are not consistently present within an individual. I also found that H. crassicornis fed a non-cnidarian diet lost cnidae over time, but the cnidarian-fed individuals did not: 3 of 10 H. crassicornis on the non-cnidarian diet lacked cnidae completely at 42 days. Future studies of cnida sequestration should be mindful that one ceras does not give an adequate representation of the distribution of sequestered cnidae.
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Affiliation(s)
- S.E. Anthony
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada; Bamfield Marine Sciences Centre, 100 Pachena Road, Bamfield, BC V0R 1B0, Canada
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Korshunova T, Martynov A. Consolidated data on the phylogeny and evolution of the family Tritoniidae (Gastropoda: Nudibranchia) contribute to genera reassessment and clarify the taxonomic status of the neuroscience models Tritonia and Tochuina. PLoS One 2020; 15:e0242103. [PMID: 33216784 PMCID: PMC7679014 DOI: 10.1371/journal.pone.0242103] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 10/27/2020] [Indexed: 12/14/2022] Open
Abstract
Nudibranch molluscs of the family Tritoniidae are widely used neuroscience model systems for understand the behavioural and genetic bases of learning and memory. However species identity and genus-level taxonomic assignment of the tritoniids remain contested. Herein we present a taxonomic review of the family Tritoniidae using integration of molecular phylogenetic analysis, morphological and biogeographical data. For the first time the identity of the model species Tritonia tetraquetra (Pallas, 1788) and Tritonia exsulans Bergh, 1894 is confirmed. T. tetraquetra distributes across the large geographic and bathymetric distances in the North-Eastern (NE) and North-Western (NW) Pacific. In turn, at NE Pacific coasts the separate species T. exsulans is commonly occured. Thus, it reveals a misidentification of T. tetraquetra and T. exsulans species in neuroscience applications. Presence of more hidden lineages within NW Pacific T. tetraquetra is suggested. The long lasting confusion over identity of the species from the genera Tritonia and Tochuina is resolved using molecular and morphological data. We also disprove a common indication about “edible T. tetraquetra” at the Kuril Islands. It is shown that Tochuina possesses specialized tritoniid features and also some characters of “arminacean nudibranchs”, such as Doridoxa and Heterodoris. Diagnoses for the families Doridoxidae and Heterodorididae are provided. Taxonomy of the genus Doridoxa is clarified and molecular data for the genus Heterodoris presented for the first time. A taxonomic synopsis for the family Tritoniidae is provided. A new genus among tritoniid taxa is proposed. Importance of the ontogeny-based taxonomy is highlighted. The cases when apomorphic characters considerably modified in a crown group due to the paedomorphosis are revealed. Tracing of the character evolution is presented for secondary gills–a key external feature of the family Tritoniidae and traditional dendronotacean nudibranchs.
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Affiliation(s)
| | - Alexander Martynov
- Zoological Museum of the Moscow State University, Moscow, Russia
- * E-mail:
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21
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Bogdanov A, Papu A, Kehraus S, Cruesemann M, Wägele H, König GM. Metabolome of the Phyllidiella pustulosa Species Complex (Nudibranchia, Heterobranchia, Gastropoda) Reveals Rare Dichloroimidic Sesquiterpene Derivatives from a Phylogenetically Distinct and Undescribed Clade. JOURNAL OF NATURAL PRODUCTS 2020; 83:2785-2796. [PMID: 32910650 DOI: 10.1021/acs.jnatprod.0c00783] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Phyllidiid nudibranchs are brightly colored gastropod mollusks, frequently encountered in coral reefs of the tropical Indo-Pacific. The lack of a protective shell is suggested to be compensated by toxic secondary metabolites that are sequestered from specific prey sponges. Our ongoing reconstruction of phyllidiid phylogeny using molecular data of more than 700 specimens, based on published data and newly collected specimens in various seasons and localities around North Sulawesi (Indonesia), demonstrates that Phyllidiella pustulosa is a species complex with at least seven well-supported clades. A metabolomic analysis of 52 specimens from all seven clades of P. pustulosa was performed. Secondary metabolite profiles were found to correlate with the phylogenetic study and not the prevailing food sponges as expected. GNPS molecular networking revealed a unique chemotype in clade 6. Detailed chemical analysis of a specimen from this chemically and genetically distinct P. pustulosa clade led to the identification of seven new sesquiterpenoids with a rare dichloroimidic moiety (1 and 4) and derivatives thereof (2, 3, 5-7). Our findings suggest that P. pustulosa clades should be raised to the species level.
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Affiliation(s)
- Alexander Bogdanov
- Institute of Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92093, United States
| | - Adelfia Papu
- Center of Molecular Biodiversity, Zoological Research Museum Alexander Koenig, 53113 Bonn, Germany
- Faculty of Mathematics and Natural Sciences, Sam Ratulangi University, Manado 95115, Indonesia
| | - Stefan Kehraus
- Institute of Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Max Cruesemann
- Institute of Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Heike Wägele
- Center of Molecular Biodiversity, Zoological Research Museum Alexander Koenig, 53113 Bonn, Germany
| | - Gabriele M König
- Institute of Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
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Martynov A, Lundin K, Picton B, Fletcher K, Malmberg K, Korshunova T. Multiple paedomorphic lineages of soft-substrate burrowing invertebrates: parallels in the origin of Xenocratena and Xenoturbella. PLoS One 2020; 15:e0227173. [PMID: 31940379 PMCID: PMC6961895 DOI: 10.1371/journal.pone.0227173] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 12/12/2019] [Indexed: 01/21/2023] Open
Abstract
Paedomorphosis is an important evolutionary force. It has previously been suggested that a soft-substrate sediment-dwelling (infaunal) environment facilitates paedomorphic evolution in marine invertebrates. However, until recently this proposal was never rigorously tested with robust phylogeny and broad taxon selection. Here, for the first time, we present a molecular phylogeny for a majority of the 21 families of one of the largest nudibranch subgroups (Aeolidacea) and show that the externally highly simplified vermiform nudibranch family, Pseudovermidae, with clearly defined paedomorphic traits and inhabiting a soft-substrata environment, is a sister group to the complex nudibranch family, Cumanotidae. We also report the rediscovery of one of the most enigmatic nudibranchs-Xenocratena suecica-on the Swedish and Norwegian coasts 70 years after it was first found. Xenocratena was described from the same location and environment in the Swedish Gullmar fjord as one of the most enigmatic vermiform organisms, Xenoturbella bocki, which represents either an original simple bilaterian body plan or secondary simplification of a more complex organisation. Our results show that Xenocratena suecica reveals an onset of parallel paedomorphic evolution so we have proposed the new family, Xenocratenidae fam. n., to accommodate the molecular and morphological disparities we discovered. The paedomorphic origin of another aeolidacean family, Embletoniidae, is also demonstrated for the first time. Thus, by presenting three independent lineages from non-closely related aeolidacean families, Xenocratenidae fam. n., Cumanotidae and Embletoniidae, we confirm with phylogenetic data that a soft-substrata burrowing-related environment strongly favours paedomorphic evolution. We suggest criteria to distinguish ancestral and derived characters in the context of modifications of ontogenetic cycles. Applying an evolutionary model of the soft substrate-driven multiple paedomorphic origin of several families of nudibranch molluscs we propose that it is plausible to extend this model to other marine invertebrates and suggest that the ancestral organisation of the enigmatic metazoan, Xenoturbella, might correspond to the larval part of a complex ancestral bilaterian ontogenetic cycle with sedentary/semi-sedentary adult stages and planula-like larval stages.
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Affiliation(s)
| | - Kennet Lundin
- Gothenburg Natural History Museum, Gothenburg, Sweden
- Gothenburg Global Biodiversity Centre, Gothenburg, Sweden
| | - Bernard Picton
- National Museums Northern Ireland, Holywood, Northern Ireland, United Kingdom
- Queen’s University, Belfast, Northern Ireland, United Kingdom
| | - Karin Fletcher
- Milltech Marine, Port Orchard, Washington, United States of America
| | - Klas Malmberg
- Gothenburg Global Biodiversity Centre, Gothenburg, Sweden
- Gothenburg Global Biodiversity Centre, Aquatilis, Gothenburg, Sweden
| | - Tatiana Korshunova
- Zoological Museum, Moscow State University, Moscow, Russia
- Koltzov Institute of Developmental Biology RAS, Moscow, Russia
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Krohne G. Hydra nematocysts in the flatworm Microstomum lineare: in search for alterations preceding their disappearance from the new host. Cell Tissue Res 2019; 379:63-71. [PMID: 31848750 DOI: 10.1007/s00441-019-03149-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 11/21/2019] [Indexed: 11/26/2022]
Abstract
Nematocysts are characteristic organelles of the phylum Cnidaria. The free-living Platyhelminth Microstomum lineare preys on Hydra oligactis and sequesters nematocysts. All nematocyst types become phagocytosed without adherent cytoplasm by intestinal cnidophagocytes. Desmoneme and isorhiza nematocysts disappear within 2 days after ingestion whereas cnidophagocytes containing the venom-loaded stenotele nematocysts migrate out of the intestinal epithelia through the parenchyma to the epidermis. Epidermally localized stenoteles are still able to discharge suggesting that this hydra organelle does preserve its physiological properties. Three to four weeks after ingestion, the majority of stenoteles disappear from M. lineare. To search for alterations of nematocysts that might precede their disappearance, flatworms were stained with acridine orange, a dye that binds to poly-γ-glutamic acid present in hydra nematocysts. The staining properties of all three nematocyst types were indistinguishable during the first 60 min after ingestion of hydra tissue whereas 15 h later, the majority of desmoneme and isorhiza had lost their stainability in striking contrast to stenoteles. In M. lineare inspected 2, 4 and 10 days after feeding, 20-40% of stenoteles had lost their stainability with acridine orange. Non-stained stenoteles had sizes similar to their stained counterparts but some of them were slightly deformed. The presented data indicate that acridine orange staining allows the detection of early alterations of all three ingested nematocyst types preceding their disappearance from M. lineare. Furthermore, they support the notion that the transport of venom-loaded stenoteles to the epidermis provides a strategy of excretion.
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Affiliation(s)
- Georg Krohne
- Imaging Core Facility Biocenter, University of Würzburg, Am Hubland, 97074, Würzburg, Germany.
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Togawa Y, Shinji J, Fukatsu T, Miura T. Development of Cerata in the Cladobranchian Sea Slug Pteraeolidia semperi (Mollusca: Gastropoda: Nudibranchia). Zoolog Sci 2019; 36:387-394. [PMID: 33319962 DOI: 10.2108/zs190057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 05/07/2019] [Indexed: 12/26/2022]
Abstract
Cladobranchian sea slugs are characterized by a number of dorsal projections, called "cerata," which are presumably involved in such biological functions as kleptocnidal defense, gas exchange, and symbiotic photosynthesis. Here, we investigated the developmental pattern of ceras formation in a cladobranchian, Pteraeolidia semperi, using field-collected individuals at various postembryonic developmental stages. As the body length increased, the total number of cerata increased in a logistic manner, up to 280 per individual. On the dorsal side of the body, the cerata exhibited a conspicuous formation of repeated, laterally-paired clusters, or rows, along the antero-posterior axis of the animals. As the body length increased, the number of ceras rows increased in a logistic manner, reaching a plateau at around 15 rows per individual. Two types of ceras clusters were observed: well-developed ceras clusters forming a glove-like structure with a basal bulge, which tended to be found in larger animals and at the anterior body region, and less-developed ceras clusters without the bulge, which tended to be found in smaller animals and at the posterior body region. Statistical and simulation analyses suggested that bulge formation underlies increased ceras number, even after the plateaued formation of new ceras rows. These results indicate that, in the postembryonic development of P. semperi, the increase of dorsal cerata entails the following processes: (i) increase of the number of ceras rows, (ii) formation of the basal bulge in each ceras cluster, and (iii) increase of the number of cerata per ceras cluster.
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Affiliation(s)
- Yumiko Togawa
- Misaki Marine Biological Station, Misaki, Miura, Kanagawa 238-0225, Japan.,National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566, Japan
| | - Junpei Shinji
- Misaki Marine Biological Station, Misaki, Miura, Kanagawa 238-0225, Japan
| | - Takema Fukatsu
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566, Japan
| | - Toru Miura
- Misaki Marine Biological Station, Misaki, Miura, Kanagawa 238-0225, Japan,
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Martynov A, Mehrotra R, Chavanich S, Nakano R, Kashio S, Lundin K, Picton B, Korshunova T. The extraordinary genus Myja is not a tergipedid, but related to the Facelinidae s. str. with the addition of two new species from Japan (Mollusca, Nudibranchia). Zookeys 2019:89-116. [PMID: 30723380 PMCID: PMC6354008 DOI: 10.3897/zookeys.818.30477] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 01/03/2019] [Indexed: 11/12/2022] Open
Abstract
Morphological and molecular data are presented for the first time in an integrative way for the genus Myja Bergh, 1896. In accordance with the new molecular phylogenies, the traditional Facelinidae is paraphyletic. Herein is presented the phylogenetic placement of true Facelinidae s. str., including the first molecular data for F.auriculata (Müller, 1776), type species of the genus Facelina Alder & Hancock, 1855. The taxonomic history of F.auriculata is reviewed. The genus Myja is related to the clade Facelinidae s. str., but shows disparate morphological traits. Two new species of the genus Myja, M.karinsp. n., and M.hyotansp. n., are described from the Pacific waters of Japan (middle Honshu), and M.cf.longicornis Bergh, 1896 is investigated from Thailand. According to molecular analysis and review of available morphological information, the genus Myja contains more hidden diversity. The family-level relationship within aeolidacean nudibranchs with emphasis on the family Facelinidae is outlined. The problem of the relationship between Facelinidae Bergh, 1889 and Glaucidae Gray, 1827 is discussed. The family Glaucidae has precedence over Facelinidae and is phylogenetically related to the core group of Facelinidae s. str., but has a profoundly modified aberrant external morphology, thus making a purely molecular-based approach to the taxonomy an unsatisfactory solution. To accommodate recently discovered hidden diversity within glaucids, the genus Glaucilla Bergh, 1861 is restored. The family Facelinidae s. str. is separate from, and not closely related to, a clade containing the genera Dondice Marcus, 1958, Godiva MacNae 1954, Hermissenda Bergh, 1879, and Phyllodesmium Ehrenberg, 1831 (= Myrrhine Bergh, 1905). The oldest valid available name for the separate ex-facelinid paraphyletic clade that contains several facelinid genera is Myrrhinidae Bergh, 1905, and resurrection of this family name under provision of the ICZN article 40.1 can preliminarily solve the problem of paraphyly of the traditional Facelinidae. “Facelinidae” s. l. needs to be further divided into several separate families, pending further study.
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Affiliation(s)
- Alexander Martynov
- Zoological Museum, Moscow State University, Bolshaya Nikitskaya Str. 6, 125009 Moscow, Russia
| | - Rahul Mehrotra
- Reef Biology Research Group, Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.,New Heaven Reef Conservation Program, 48 Moo 3, Koh Tao, Suratthani 84360, Thailand
| | - Suchana Chavanich
- Reef Biology Research Group, Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.,Center for Marine Biotechnology, Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Rie Nakano
- Kuroshio Biological Research Foundation, 560-I, Nishidomari, Otsuki, Hata-Gun, Kochi, 788-0333, Japan
| | - Sho Kashio
- Natural History Museum, Kishiwada City, 6-5 Sakaimachi, Kishiwada, Osaka Prefecture 596-0072, Japan
| | - Kennet Lundin
- Gothenburg Natural History Museum, Box 7283, S-40235, Gothenburg, Sweden.,Gothenburg Global Biodiversity Centre, Box 461, S-40530, Gothenburg, Sweden
| | - Bernard Picton
- National Museums Northern Ireland, Holywood, Northern Ireland, UK.,Queen's University, Belfast, Northern Ireland, UK
| | - Tatiana Korshunova
- Zoological Museum, Moscow State University, Bolshaya Nikitskaya Str. 6, 125009 Moscow, Russia.,Koltzov Institute of Developmental Biology RAS, 26 Vavilova Str., 119334 Moscow, Russia
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