V - The development ofHaliotis Tuberculata, with special reference to organogenesis during torsion

Publisher Website
Google Scholar
Abstract
Investigation of the development ofHaliotis tuberculata, Linnaeus, was undertaken as a natural sequel to an examination of the bionomics and anatomy ofHaliotis(Crofts 1929, p. 159). It is an attempt to elucidate the organogenesis during the changing larval habits, in the hope of adding to the scanty ontogenetical evidence available towards solving the problems of gastropod evolution. Excellent accounts of the embryonic phase, including patiently worked out details of the cleavage and of gastrulation, have been published forCrepidula(Conklin 1897),Patella(Patten 1886; Wilson 1904; and Smith 1935),Trochus(Robert 1902),Physa(Wierzejski 1905),Dentalium(Wilson 1904). The only comprehensive accounts of gastropod larval development already published are ofPaludina(Erlanger 1891; Tonniges 1896; Drummond 1902; Andersen 1924) and ofPatella(Patten 1886; Smith I935). The accounts ofPaludinaelucidate the details of development of the coelom and its derivatives. The viviparous habit and consequent loss of free larval life inPaludina, however, make it a very unsuitable example of gastropod development. Evolutionary stages are more likely to be traced from the development of less specialized gastropods, an adequate selection of whose free-living larval stages can be obtained. The larval development ofPatel, Acmaea, TrochusandHaliotishas been described, in varying completeness for the different genera. Patten’s work onPatella coerulea(1886) gives a description only of the beginning of organogenesis. After a lapse of fifty years a more detailed account of the development ofP. vulgatahas been given by Smith (1935). This work gives a new interpretation of the development of the mesoderm, of the muscles and of the nervous system. The dorsal retractor muscle of the larva, which Patten indicated forP. coerula, is shown inP. vulgatato be placed asymmetrically and torsion takes place “ under the action” of this muscle.

This publication has 6 references indexed in Scilit: