Reproduction of Marine Invertebrates. Molluscs: Gastropods by Arthur Giese (Eds.) PDF

By Arthur Giese (Eds.)

ISBN-10: 0122825047

ISBN-13: 9780122825040

ISBN-10: 0323153054

ISBN-13: 9780323153058

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Additional info for Reproduction of Marine Invertebrates. Molluscs: Gastropods and Cephalopods

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Houston ( 1 9 7 1 ) found for Nucella canaliculata that the aggregation consisted only of egg-laying females. Males remained dispersed throughout this period. Communal egg laying is also described for Conus (D'Asaro, 1 9 7 0 ) . In this case, however, some males were detected in the aggregated mass. 2 SEX RECOGNITION There is evidence of active sex recognition in prosobranchs. Cate described a bubble of mucus released by Mitra idae that apparently attracted males. Edwards ( 1 9 6 8 ) found that male Olivella were attracted to, and followed, trails of mucus of sexually mature females.

As the head elongates and becomes compact, protoplasmic residues may be extruded from the spermatid head. 2. Middle piece: During spermiogenesis the mitochondria fuse and generally form four spheres at the posterior end of the spermatid. These mitochondrial spheres fuse into a ring around the flagellum at the posterior end of the nucleus. 3. Tail: The flagellar filament grows out from the posterior centriole through the mitochondrial mass. The flagellum may be covered along part of its length with a thin layer of protoplasm.

However, 99% of the snails with a shell length of 8 mm or more were infected. As well, males were more heavily infected than females. 8 Reproductive Behavior In general, reproductive behavior in prosobranchs is unexceptional and consequently is not well reported. There do exist, however, observations pertaining to spawning aggregations, sex recognition, copulatory behavior, and brooding. 1 SPAWNING AGGREGATION In some species that are otherwise solitary, pairing occurs during times of copulation.

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Reproduction of Marine Invertebrates. Molluscs: Gastropods and Cephalopods by Arthur Giese (Eds.)


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