External gestation of Exogone naidina Öersted, 1845 (Polychaeta, Syllidae): ventral attachment of eggs and embryos

Mastrodonato, María; Sciscioli, Margherita; Lepore, Elena; Gherardi, Miriam; Giangrande, Adriana; Mercati, David; Dallai, Romano; Lupetti, Pietro

doi:10.1016/s0040-8166(03)00051-x

Cited by 12 publications

(14 citation statements)

References 6 publications

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“…A similar reproductive strategy has been confirmed in myrianida (= Autolytus) edwarsi (schiedges, 1979), and the sole examined sperm morphology from an autolytine showed an ent-aquasperm type (Franzén, 1982). Brood protection is also common in other eusyllinae species, such as some small Pionosyllis (pierantoni, 1903), but it is typical of small-sized epigamic exogoninae having ent-aquasperm (Mastrodonato et al, 2003). thus, it can be hypothesised that brood protection is an adaptive convergence in several small-sized species.…”

Section: Discussionmentioning

confidence: 63%

Ultra-estructura de los espermatozoides de <i>Odontosylis ctenostoma</i> (Polychaeta: Syllidae) y su aplicación a la filogenia y biología reproductiva de los Sílidos

Giangrande¹,

Gherardi²,

Lepore³

et al. 2008

Sci. Mar.

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suMMArY: the analysis of the complex reproductive patterns of syllidae may drastically change the taxonomic hierarchy of the family. to further contribute to the knowledge of syllidae we have described the sperm ultra-structure and some steps of spermiogenesis of Odontosyllis ctenostoma claparède, 1868, the first non interstitial eusylline investigated. the mature sperm has a bell-shaped acrosome and contains electron-dense granular material and thin filaments. the barrel-shaped nucleus bears two depressions: one anterior facing the acrosome and the other posterior partially containing the distal centriole and up to six mitochondria. Odontosyllis ctenostoma spermatozoa can be ascribed to the ect-aquasperm type typical of species practising external fertilisation. this morphology is not in complete accordance either with the particular brood protection reported for the species or the egg size. the sperm is similar to those of the syllinae species thus far investigated, but the acrosome resembles that of the exogonine spermatid. some authors consider Odontosyllis to be phylogenetically closer to syllinae, though it shares epigamy with exogoninae. others have hypothesised that the exogonine sperm could have been derived from sylline sperm by simplification. in our hypothesis this could have happened through a gradual passage from an Odontosyllis-like eusylline ancestor.Keywords: sperm morphology, ultrastructure, polychaeta, eusyllinae, reproduction, phylogeny.resuMen: Ultra-estructura de los espermatozoides de OdOntOsyllis ctenOstOma (Polychaeta: Syllidae) y su aplicación a la filogenia y biología reproductiva de los Sílidos. -La jerarquía taxonómica actualmente aceptada de la familia syllidae podría cambiar drásticamente después de un profundo análisis de las modalidades reproductivas; especialmente para la subfamilia eusyllinae que es considerada parafilética. con el objetivo de dar una mayor contribución al conocimiento de la biología de la familia syllidae, en este trabajo se ha estudiado la ultraestructura del espermatozoide y algunas fases de la espermatogénesis de Odontosyllis ctenostoma claparède, 1868. el espermatozoide maduro presenta un acrosoma en forma de campana, cuya parte basal contiene material electrón denso donde se originan filamentos. el núcleo es en forma de barril con dos depresiones: una en la base del acrosoma y otra posterior que contiene seis mitocondrias que circundan los centriolos. el espermatozoide de O. ctenostoma puede ser adscrito al tipo "ect-aquasperma" que es típico en aquellas especies que tienen una fecundación externa. esta morfología no concuerda con su biología reproductiva y con el tamaño de los huevos. el espermatozoide es muy similar a los de especies de la subfamilia syllinae estudiadas hasta el momento, si bien el acrosoma es más similar al acrosoma del espermatidio de exogoninae. según algunos autores Odontosyllis es filogenéticamente similar a la subfamilia syllinae si bien comparte la epigamia con la subfamilia exogoninae. en otros trabajos se ha formulado la hipóte...

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Section: Discussionmentioning

confidence: 63%

Ultra-estructura de los espermatozoides de <i>Odontosylis ctenostoma</i> (Polychaeta: Syllidae) y su aplicación a la filogenia y biología reproductiva de los Sílidos

Giangrande¹,

Gherardi²,

Lepore³

et al. 2008

Sci. Mar.

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“…Especially interesting were the SEM photos taken to the new Australian genus and species Nooralia bulgannabooyanga San Martín, 2002, because it is up to date, the unique syllid which develops compound notochaetae for dorsal brooding of eggs (San Martín, 2002). Ventral brooding of eggs and development of juveniles attached to females in some species were recorded and photographied by San Martín (2003), Mastrodonato et al (2003), Nogueira et al (2004), andBöggemann &Purschke (2005) (figs. 10C, D).…”

Section: Biology and Reproductionmentioning

confidence: 99%

Contribution of Scanning Electron Microscope to the Study of Morphology, Biology, Reproduction, and Phylogeny of the Family Syllidae (Polychaeta)

Martín¹,

Aguado²

2012

Scanning Electron Microscopy

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“…Syllids are mostly dioic usually lacking an evident sexual dimorphism in both atokous and epitokous individuals (San Martín 2003). The suppression of epitoky is often associated with hermaphroditism (Bührmann et al 1996;Garwood 1991;Giangrande 1997;Kuper and Westheide 1997) and external gestation (Mastrodonato et al 2003).…”

Section: Introductionmentioning

confidence: 99%

Sperm ultrastructure of three Syllinae (Annelida, Phyllodocida) species with considerations on syllid phylogeny and Syllis vittata reproductive biology

et al. 2010

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Phylogeny of Syllidae is under debate due to new studies based on molecular and morphological data. The noticeable taxonomic diversity of syllids (about 700 listed species) is also mirrored in the array of reproductive strategies as well as in sperm morphology, counting a display of forms already supposed to reflect phylogenetic relationships between the species. The sperm ultrastructure of Syllis gerlachi, S. prolifera and S. vittata is herein presented and compared to the Syllinae species studied previously. Moreover, the egg structure and the gamete allocation within stolons of S. vittata are particularly investigated. Both male germinal cells at different level of maturation and oocytes were found in the same individual of S. vittata, suggesting simultaneous hermaphroditism. The ultrastructural analysis revealed that the observed spermatozoa belong to the ect-aquasperm type resembling those of the similar studied species (Syllis sp., S. pigmentata and S. krohni). Differences in the acrosome structure and nucleus shape are in accordance with a recent phylogenetic reconstruction and suggest a trend in the evolution of spermatozoa in Syllinae toward the development of the apical part. However, further molecular and ultrastructural analyses are needed to support this hypothesis. This is the first record of simultaneous hermaphroditism within Syllinae.

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External gestation of Exogone naidina Öersted, 1845 (Polychaeta, Syllidae): ventral attachment of eggs and embryos

Cited by 12 publications

References 6 publications

Ultra-estructura de los espermatozoides de <i>Odontosylis ctenostoma</i> (Polychaeta: Syllidae) y su aplicación a la filogenia y biología reproductiva de los Sílidos

Ultra-estructura de los espermatozoides de <i>Odontosylis ctenostoma</i> (Polychaeta: Syllidae) y su aplicación a la filogenia y biología reproductiva de los Sílidos

Contribution of Scanning Electron Microscope to the Study of Morphology, Biology, Reproduction, and Phylogeny of the Family Syllidae (Polychaeta)

Sperm ultrastructure of three Syllinae (Annelida, Phyllodocida) species with considerations on syllid phylogeny and Syllis vittata reproductive biology

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