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Martino EDI. Scanning electron microscopy study of Lars Silns cheilostome bryozoan type specimens in the historical collections of natural history museums in Sweden. Zootaxa 2023; 5379:1-106. [PMID: 38220795 DOI: 10.11646/zootaxa.5379.1.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Indexed: 01/16/2024]
Abstract
The type specimens of 42 cheilostome bryozoan species introduced by Lars Siln between 1938 and 1954 and housed at three different Swedish institutions (the Swedish Museum of Natural History in Stockholm, the Biological Museum in Lund and the Museum of Evolution in Uppsala) are here revised using scanning electron microscopy, with two exceptions, for the first time. As a result of this revision, new morphological observations were made for some species, such as ooecia in Antropora erecta, a costal pseudopore in Jullienula hippocrepis, intracolonial variation in the number of intracostal windows in Costaticella gisleni, and oral spines in Triphyllozoon mauritzoni. Some other observations confirmed the presence of structures/polymorphs in type material that had previously only been noted in non-type specimens, such as spinose interzooidal kenozooids in Retevirgula triangulata and putative brooding zooids in Bugulina kiuschiuensis. Structures originally interpreted as hydroid tube openings on the dorsal side of Triphyllozoon microstigmatum were confirmed to be avicularia, while the supposed kenozooidal attachment rootlet of Fedora nodosa might be the polypide tube of a coronate scyphozoan. In addition, the original combination Heliodoma goesi is here reinstated after Lagaaij assigned the species to Setosellina in 1963. The following new combinations are also proposed: Labioporella aviculifera for Siphonoporella aviculifera; Mangana canui and Mangana incrustata for Callopora canui and Tegella incrustata, respectively; Sphaerulobryozoon ovum for Fedora ovum. Lectotypes were selected when appropriate. This work clarifies the exact identity of some species that have never been recorded after their first description, such as Stylopoma magnovicellata and three species of Triphyllozoon, and contributes to the current increasing effort to digitize historical key specimens in natural history museum collections.
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Decker SH, Hirose M, Lemer S, Kuklinski P, Spencer HG, Smith AM, Schwaha T. Boring bryozoans: an investigation into the endolithic bryozoan family Penetrantiidae. ORG DIVERS EVOL 2023; 23:743-785. [PMID: 38046835 PMCID: PMC10689564 DOI: 10.1007/s13127-023-00612-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 04/11/2023] [Indexed: 12/05/2023]
Abstract
An endolithic lifestyle in mineralized substrates has evolved multiple times in various phyla including Bryozoa. The family Penetrantiidae includes one genus with ten extant and two fossil species. They predominantly colonize the shells of molluscs and establish colonies by chemical dissolution of calcium carbonate. Based on several morphological characters, they were described to be either cheilostome or ctenostome bryozoans. For more than 40 years, neither the characters of species identity and systematics nor the problem of their phylogeny was approached. Consequently, the aim of this study is to reevaluate species identities and the systematic position of the genus Penetrantia by analyzing at least six different species from eight regions with the aid of modern methods such as confocal laser scanning microscopy and 3D-reconstruction techniques. This study demonstrates that the musculature associated with the operculum and brood chamber shows significant differences from the cheilostome counterparts and seems to have evolved independently. Together with the presence of other ctenostome-like features such as true polymorphic stolons and uncalcified body wall, this finding supports a ctenostome affinity. Operculum morphology reveals many new species-specific characters, which, together with information about gonozooid morphology, tentacle number, and zooid size ranges, will enhance species identification. It also revealed a probable new species in Japan as well as potential cryptic species in France and New Zealand. In addition, this study increases the known distribution range of the family and its substrate diversity. Altogether, the new information collated here provides the basis for future work on a neglected taxon. Supplementary Information The online version contains supplementary material available at 10.1007/s13127-023-00612-z.
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Affiliation(s)
- Sebastian H. Decker
- Department of Evolutionary Biology, University of Vienna, Schlachthausgasse 43, 1030 Vienna, Austria
| | - Masato Hirose
- School of Marine Biosciences, Kitasato University, Kitasato 1-15-1, Sagamihara-Minami, Kanagawa, 252-0373 Japan
| | - Sarah Lemer
- Marine Laboratory, UOG Station, Mangilao, Guam 96923 USA
| | - Piotr Kuklinski
- Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland
| | | | - Abigail M. Smith
- Department of Marine Science, University of Otago, Dunedin, New Zealand
| | - Thomas Schwaha
- Department of Evolutionary Biology, University of Vienna, Schlachthausgasse 43, 1030 Vienna, Austria
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Morphology and life cycle of an epiphytic pherusellid ctenostome bryozoan from the Mediterranean Sea. ORG DIVERS EVOL 2020. [DOI: 10.1007/s13127-020-00443-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
AbstractThe epiphytic community on the endemic seagrass Posidonia oceanica from the Mediterranean Sea is well studied, but still harbors some little investigated epiphytic bryozoans. Numerous, yet always small colonies of Pherusella sp. were recently encountered in the Northern Adriatic Sea. The aim of this study was to generate data on the life history, colonial development, and reproduction of the Mediterranean population of this Pherusella species in order to gain a better understanding of the biology of this understudied species. The morphology of adult zooids was also studied due to the lack of recent data on the family with state-of-the-art techniques. Long-term observation shows that this species is highly adapted to an epiphytic life cycle with short generation time throughout the year. First laboratory cultures appear promising in establishing a reliable model system for developmental and ecological studies. Larvae are easily obtainable, and metamorphosis and colonial growth patterns are documented here for the first time. The morphology of adults shows distinct similarities with other pheruselllids and, along with the neuromuscular system, is similar to other alcyonidioideans supporting the close relationship of these taxa. This study constitutes one of the first long-time observations of the life cycle and colonial growth of a pherusellid bryozoan, including morphological data about the neuromuscular system of an otherwise incompletely known group of bryozoans. Pherusella sp. appears to be a promising candidate for future studies since it is easy to collect and maintain under laboratory conditions as well as to obtain different developmental stages.
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Shevchenko ET, Varfolomeeva MA, Nekliudova UA, Kotenko ON, Usov NV, Granovitch AI, Ostrovsky AN. Electra vs Callopora: life histories of two bryozoans with contrasting reproductive strategies in the White Sea. INVERTEBR REPROD DEV 2020. [DOI: 10.1080/07924259.2020.1729260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Ekaterina T. Shevchenko
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Marina A. Varfolomeeva
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Uliana A. Nekliudova
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
- Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, Vienna, Austria
| | - Olga N. Kotenko
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Nikolay V. Usov
- White Sea Biological Station, Zoological Institute, Russian Academy of Sciences, Saint Petersburg, Russia
| | - Andrei I. Granovitch
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Andrew N. Ostrovsky
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
- Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, Vienna, Austria
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Burgess SC, Sander L, Bueno M. How relatedness between mates influences reproductive success: An experimental analysis of self-fertilization and biparental inbreeding in a marine bryozoan. Ecol Evol 2019; 9:11353-11366. [PMID: 31641478 PMCID: PMC6802076 DOI: 10.1002/ece3.5636] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 07/18/2019] [Accepted: 08/06/2019] [Indexed: 11/21/2022] Open
Abstract
Kin associations increase the potential for inbreeding. The potential for inbreeding does not, however, make inbreeding inevitable. Numerous factors influence whether inbreeding preference, avoidance, or tolerance evolves, and, in hermaphrodites where both self-fertilization and biparental inbreeding are possible, it remains particularly difficult to predict how selection acts on the overall inbreeding strategy, and to distinguish the type of inbreeding when making inferences from genetic markers. Therefore, we undertook an empirical analysis on an understudied type of mating system (spermcast mating in the marine bryozoan, Bugula neritina) that provides numerous opportunities for inbreeding preference, avoidance, and tolerance. We created experimental crosses, containing three generations from two populations to estimate how parental reproductive success varies across parental relatedness, ranging from self, siblings, and nonsiblings from within the same population. We found that the production of viable selfed offspring was extremely rare (only one colony produced three selfed offspring) and biparental inbreeding more common. Paternity analysis using 16 microsatellite markers confirmed outcrossing. The production of juveniles was lower for sib mating compared with nonsib mating. We found little evidence for consistent inbreeding, in terms of nonrandom mating, in adult samples collected from three populations, using multiple population genetic inferences. Our results suggest several testable hypotheses that potentially explain the overall mating and dispersal strategy in this species, including early inbreeding depression, inbreeding avoidance through cryptic mate choice, and differential dispersal distances of sperm and larvae.
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Affiliation(s)
- Scott C. Burgess
- Department of Biological ScienceFlorida State UniversityTallahasseeFLUSA
| | - Lisa Sander
- Department of Biological ScienceFlorida State UniversityTallahasseeFLUSA
| | - Marília Bueno
- Department of Biological ScienceFlorida State UniversityTallahasseeFLUSA
- Present address:
Departamento de Biologia AnimalInstituto de BiologiaUniversidade Estadual de Campinas – UNICAMPCampinasBrazil
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Pröts P, Wanninger A, Schwaha T. Life in a tube: morphology of the ctenostome bryozoan Hypophorella expansa. ZOOLOGICAL LETTERS 2019; 5:28. [PMID: 31410295 PMCID: PMC6686267 DOI: 10.1186/s40851-019-0142-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 07/08/2019] [Indexed: 06/10/2023]
Abstract
Bryozoa is a large phylum of colonial aquatic suspension feeders. The boring ctenostome Hypophorella expansa is unique and inhabits parchment-like polychaete tubes. Morphological studies date back to the nineteenth century, but distinct adaptations to this specific habitat have not been properly analysed, which prompted us to reexamine the morphology of this recently encountered species. The colony of H. expansa is composed of elongated stolonal kenozooids with a distal capsule-like expansion. A median transversal muscle is present in the latter, and one autozooid is laterally attached to the capsule. Unique stolonal wrinkles are embedded in the thin parts of the stolons. Single autozooids are attached in an alternating right-left succession on subsequent stolons. Polypide morphology including digestive tract, muscular system and most parts of the nervous system are similar to other ctenostomes. The most obvious apomorphic features of Hypophorella are space balloons and the gnawing apparatus. The former are two fronto-lateral spherical structures on autozooids, which provide space inside the tube. The latter perforates layers of the polychaete tube wall and consists of two rows of cuticular teeth that, together with the entire vestibular wall, are introvertable during the protrusion-retraction process. The apertural muscles are in association with this gnawing apparatus heavily modified and show bilateral symmetry. Adaptations to the unique lifestyle of this species are thus evident in stolonal wrinkles, autozooidal space balloons and the gnawing apparatus. The growth pattern of the colony of H. expansa may aid in rapid colonization of the polychaete tube layers.
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Affiliation(s)
- Philipp Pröts
- Department of Integrative Zoology, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
| | - Andreas Wanninger
- Department of Integrative Zoology, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
| | - Thomas Schwaha
- Department of Integrative Zoology, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
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Shunatova N, Tamberg Y. Body cavities in bryozoans: Functional and phylogenetic implications. J Morphol 2019; 280:1332-1358. [DOI: 10.1002/jmor.21034] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 06/11/2019] [Accepted: 06/13/2019] [Indexed: 12/31/2022]
Affiliation(s)
- Natalia Shunatova
- Department of Invertebrate Zoology; St. Petersburg State University; St. Petersburg Russia
| | - Yuta Tamberg
- Department of Invertebrate Zoology; St. Petersburg State University; St. Petersburg Russia
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Schwaha TF, Wanninger A. Unity in diversity: a survey of muscular systems of ctenostome Gymnolaemata (Lophotrochozoa, Bryozoa). Front Zool 2018; 15:24. [PMID: 29930689 PMCID: PMC5992719 DOI: 10.1186/s12983-018-0269-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 05/17/2018] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Myoanatomical studies of adult bryozoans employing fluorescent staining and confocal laser scanning microscopy (CLSM) have been chiefly conducted on freshwater bryozoans. The diversity of muscular systems in the marine bryozoans is currently not well known with only two species being studied in more detail. The aim of this study is to unravel the diversity of muscle systems of 15 ctenostome bryozoans by phalloidin-coupled fluorescence stainings combined with CLSM. RESULTS In general, the myoanatomy of the selected ctenostomes shows significant similarities and consists of 1) muscles associated with the body wall, 2) apertural muscles, 3) lophophoral muscles, 4) tentacle sheath muscles, 5) digestive tract muscles and 6) the prominent retractor muscles. Differences are present in the arrangement of the apertural muscles from generally three muscles sets of four bundles, which in some species can be partially reduced or modified into a bilateral arrangement. The cardiac region of the digestive tract shows a distinct sphincter in four of the six studied clades. In some cases the cardiac region forms a prominent proventriculus or gizzard. Tentacle sheath muscles in victorelloideans and walkerioideans are arranged diagonally and differ from the simple longitudinal muscle arrangements common to all other taxa. Lophophoral base muscles consist of four sets that vary in the size of the sets and in the shape of the inner lophophoral ring, which either forms a complete ring or separate, intertentacular muscle bundles. The stolon-forming walkeridiodean ctenostomes show prominent transverse muscles in their stolons. These are always present in the shorter side stolons, but their occurrence in the main stolon seems to depend on the colony form, being present in creeping but absent in erect colony forms. CONCLUSIONS This study represents the first broad survey of muscular systems in adult ctenostome bryozoans and shows a certain degree of conservation in a series of diverse colony forms belonging to five major clades. However, several myoanatomical features such as the cardiac sphincter, basal (possibly transitory) cystid muscles, tentacle sheath muscles or apertural muscle arrangement vary across taxa and thus show a high potential for the assessment of character evolution within ctenostomes. As such, this study represents an essential contribution towards determining and reconstructing the character states of the bryozoan ground pattern once a reliable phylogenetic tree of the whole phylum becomes available.
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Affiliation(s)
- Thomas F. Schwaha
- University of Vienna, Department of Integrative Zoology, Althanstraße 14, 1090 Vienna, Austria
| | - Andreas Wanninger
- University of Vienna, Department of Integrative Zoology, Althanstraße 14, 1090 Vienna, Austria
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9
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McCartney MA. SEX ALLOCATION AND MALE FITNESS GAIN IN A COLONIAL, HERMAPHRODITIC MARINE INVERTEBRATE. Evolution 2017; 51:127-140. [DOI: 10.1111/j.1558-5646.1997.tb02394.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/1995] [Accepted: 09/17/1996] [Indexed: 11/29/2022]
Affiliation(s)
- Michael A. McCartney
- Section of Evolution and Ecology Center for Population Biology University of California Davis California 95616
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10
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Shunatova NN, Ostrovsky AN. Individual autozooidal behaviour and feeding in marine bryozoans. ACTA ACUST UNITED AC 2012. [DOI: 10.1080/00364827.2001.10420468] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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11
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Pattern of occurrence of supraneural coelomopores and intertentacular organs in Gymnolaemata (Bryozoa) and its evolutionary implications. ZOOMORPHOLOGY 2011. [DOI: 10.1007/s00435-011-0122-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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12
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Johnson CH. Effects of selfing on offspring survival and reproduction in a colonial simultaneous hermaphrodite (Bugula stolonifera, Bryozoa). THE BIOLOGICAL BULLETIN 2010; 219:27-37. [PMID: 20813987 DOI: 10.1086/bblv219n1p27] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Understanding the consequences of selfing in simultaneous hermaphrodites requires investigating potential deleterious effects on fitness at all stages of life. In this study, I examined the effects of selfing throughout the life cycle of the marine bryozoan Bugula stolonifera, a colonial simultaneous hermaphrodite. In 2008, larvae from field-collected colonies were cultured through metamorphosis to reproductively mature colonies either in the presence of one other colony, the paired treatment, or alone, the solitary treatment. Results demonstrated that selfing in this species is possible, in that colonies in the solitary treatment produced viable larvae that successfully completed metamorphosis. On average, however, these colonies released significantly fewer larvae, which experienced reduced rates of metamorphic initiation and completion compared to the paired treatment. These experiments were extended in 2009, when metamorphs from colonies reared in the solitary (n = 58) and paired (n = 61) treatments were transferred to the field for growth to reproductive maturity and then brought back to the laboratory for larval collection. Results revealed additional deleterious effects associated with selfing, as no viable larvae were recovered from colonies deriving from the solitary treatment. In contrast, offspring from the paired treatment released 1030 larvae and 99% initiated metamorphosis, 97% of which completed metamorphosis. Overall, selfed larvae not only had significantly decreased chances of survival, but those that did survive did not successfully reproduce.
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Affiliation(s)
- Collin H Johnson
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
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Ultrastructure of mesoderm formation and development in Membranipora membranacea (Bryozoa: Gymnolaemata). ZOOMORPHOLOGY 2009. [DOI: 10.1007/s00435-009-0099-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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14
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Dyrynda PEJ, King PE. Sexual reproduction in Epistomia bursaria (Bryozoa: Cheilostomata), an endozooidal brooder without polypide recycling. J Zool (1987) 2009. [DOI: 10.1111/j.1469-7998.1982.tb02080.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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15
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Ultrastructure of spermiogenesis in Cristatella mucedo Cuvier (Bryozoa: Phylactolaemata: Cristatellidae). ZOOMORPHOLOGY 2009. [DOI: 10.1007/s00435-009-0088-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Temkin MH, Bortolami SB. Waveform dynamics of spermatozeugmata during the transfer from paternal to maternal individuals of Membranipora membranacea. THE BIOLOGICAL BULLETIN 2004; 206:35-45. [PMID: 14977728 DOI: 10.2307/1543196] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Analysis of standard (60 frames/s) and high-speed (200 frames/s) video records revealed that unencapsulated sperm aggregates (spermatozeugmata) of the gymnolaemate bryozoan Membranipora membranacea spontaneously generate at least three types of waveforms: small amplitude, large amplitude, and reverse. All three waveforms significantly differed from one another in amplitude. Additionally, small- and large-amplitude waveforms propagated from the base to the tip of axonemes, whereas the reverse waveform propagated from the tip to the base of axonemes. Small-amplitude waveforms, which were generated most frequently by spermatozeugmata in the paternal perivisceral coelom and in the water column after spawning, produced almost no curvature of the axoneme. Large-amplitude waveforms were produced by spermatozeugmata in the water column and within lophophores. Reverse waveforms were produced while spermatozeugmata moved tail-end forward through the paternal tentacles during spawning and after spermatozeugmata had contacted the intertentacular organ (ITO), a tubular structure that spermatozeugmata pass through to enter the maternal coelom and that eggs pass through to enter the seawater. The production of reverse waveforms by spermatozeugmata after reaching the ITO may be evidence for a behavioral response of bryozoan sperm to conspecific maternal individuals.
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Affiliation(s)
- M H Temkin
- Biology Department, St. Lawrence University, Canton, New York 13617, USA.
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18
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Ryland JS. Convergent colonial organization and reproductive function in two bryozoan species epizoic on gastropod shells. J NAT HIST 2001. [DOI: 10.1080/002229301300323929] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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19
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FRANZÉN ÅKE. Spermiogenesis, sperm ultrastructure and sperm transport inLoxosoma pectinaricola(Entoprocta). INVERTEBR REPROD DEV 2000. [DOI: 10.1080/07924259.2000.9652411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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20
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Ostrovsky AN. Comparative Studies of Ovicell Anatomy and Reproductive Patterns inCribrilina annulataandCelleporella hyalina(Bryozoa: Cheilostomatida). ACTA ZOOL-STOCKHOLM 1998. [DOI: 10.1111/j.1463-6395.1998.tb01280.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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FRANZÉN ÅKE. Spermiogenesis, sperm structure and spermatozeugmata in the gymnolaematous bryozoanElectra pilosai(Bryozoa, Gymnolaemata). INVERTEBR REPROD DEV 1998. [DOI: 10.1080/07924259.1998.9652353] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Abstract
The occurrence of outcrossing in benthic hermaphroditic colonial invertebrates has received much historical debate and little demonstration. Direct genetic study of this question using routine techniques has been limited by both the amount of material required and the detection of adequate DNA polymorphisms. However, the recent development of molecular techniques that require no a-priori sequence data provides new approaches to the characterization of both tiny and genetically similar individuals. Random amplification of polymorphic DNA (the RAPD assay) was used to amplify fragments of DNA (via the polymerase chain reaction) to obtain fingerprints of parental colonies and larval offspring of the hermaphroditic freshwater bryozoan Cristatella mucedo. Here we report the first positive and direct genetic evidence for outcrossing in bryozoans. However, we find that outcrossing generates only low levels of genetic variation in populations that are highly clonal.
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Affiliation(s)
- C S Jones
- Department of Biochemistry, University of Oxford, UK
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23
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Harvell CD, Caswell H, Simpson P. Density effects in a colonial monoculture: experimental studies with a marine bryozoan (Membranipora membranacea L.). Oecologia 1990; 82:227-237. [DOI: 10.1007/bf00323539] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/1989] [Revised: 08/30/1989] [Accepted: 10/16/1989] [Indexed: 11/28/2022]
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24
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Reed CG. The reproductive biology of the gymnolaemate bryozoanBowerbankia gracilis(Ctenostomata: Vesiculariidae). ACTA ACUST UNITED AC 1988. [DOI: 10.1080/00785326.1988.10430816] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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25
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Cancino JM, Hughes RN. The zooidal polymorphism and astogeny ofCelleporella hyalina(Bryozoa: Cheilostomata). J Zool (1987) 1988. [DOI: 10.1111/j.1469-7998.1988.tb04891.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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26
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27
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Ultrastructure of spermatids and spermatozoa in the cyclostomatous bryozoan Tubulipora (Bryozoa, Cyclostomata). ZOOMORPHOLOGY 1984. [DOI: 10.1007/bf00312132] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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28
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Hall D. Larval release in Celleporaria Apiculata(Busk) (Bryozoa: Ascophora). J NAT HIST 1982. [DOI: 10.1080/00222938200770151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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29
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30
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Emig CC. Le lophophore—structure significative des Lophophorates (Brachiopodes, Bryozoaires, Phoronidiens). ZOOL SCR 1976. [DOI: 10.1111/j.1463-6409.1976.tb00690.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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32
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Abstract
Monticules, regularly arranged modified areas on Paleozoic Bryozoa, may represent regions from which water currents produced by lophophores of adjacent feeding zoids escaped. Such circulation Patterns have been observed Recent forms.
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Afzelius BA. Fine structure of the spermatozoon of Tubularia larynx (Hydrozoa, Coelenterata). JOURNAL OF ULTRASTRUCTURE RESEARCH 1971; 37:679-89. [PMID: 4400170 DOI: 10.1016/s0022-5320(71)80031-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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