By Arthur Giese (Eds.)
Read Online or Download Reproduction of Marine Invertebrates. Molluscs: Gastropods and Cephalopods PDF
Similar zoology books
An bold, complete evaluate of the present prestige of neotropical migratory birds within the united states, and the tools and techniques for holding migrant populations. This booklet covers the whole scope of the topic, with chapters reviewing and assessing the subjects written as consensus files by way of a number of of the best employees.
The Arashiyama crew of jap macaques holds a unique position in primatology as one of many longest always studied non-human primate populations on the planet. The ensuing long term information offer a different source for researchers, letting them stream past cross-sectional reports to take on greater concerns regarding person, matrilineal and crew histories.
- Catalogue of the neotropical Squamata: Part 2, lizards and amphisbaenians
- The Complete Field Guide to Butterflies of Australiа
- 101 Things You Don't Know About Science and No One Else Does Either
- Primates in Fragments: Complexity and Resilience
- The Accidental Scientist. The Role of Chance and Luck in Scientific Discovery
- Turkey Hunting
Additional info for Reproduction of Marine Invertebrates. Molluscs: Gastropods and Cephalopods
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.
Reproduction of Marine Invertebrates. Molluscs: Gastropods and Cephalopods by Arthur Giese (Eds.)