A 'G' chromosome banding study of three cupped oyster species: Crassostrea gigas, Crassostrea angulata and Crassostrea virginica (Mollusca: Bivalvia)

The G-banding technique was performed on chromosomes from gill tissue of three cupped oyster species : Crassostrea gigas, Crassostrea angulata and Crassostrea virginica. Identification of the ten individual chromosome pairs was obtained. Comparative analysis of G-banded karyotypes of the three species showed that their banding patterns generally resembled each other, with chromosome pair 3 being similar in all three species. However, differences from one species to another were also observed. The G-banding pattern highlighted greater similarities between C. gigas and C. angulata than between these two species and C. virginica, thus providing an additional argument for genetic divergence between, these two evolutionary lineages. C. gigas and C. angulata showed a different G-banding patterns on the two arms of chromosome pair 7, which agrees with teir taxonomic separation. The application of this banding technique offers a new approach to specific problems in oyster taxonomy and genetics

Sympatric Australian Lasaea species (Mollusca: Bivalvia) differ in their ploidy levels, reproductive modes and developmental modes

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74949/1/j.1096-3642.1999.tb01382.x.pd

Description de Spirorbis (Laeospira) pseudomilitaris n. sp., Polych\ue8te Spirorbinae, et de sa larve

Volume: 37Start Page: 495End Page: 50

Cytogénétique de Bivalves d'intérêt commercial (les Huîtres)

PARIS-BIUSJ-Thèses (751052125) / SudocCentre Technique Livre Ens. Sup. (774682301) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Karyotypes of

The chromosomes of three commercially important species of veneroid bivalves were studied: Cerastoderma edule (Cardiidae), Venerupis pullastra and Venerupis rhomboides (Veneridae, Tapetinae) using conventional Giemsa staining and morphometric measurements. C. edule showed a diploid chromosome number of 2n=38 and a variable occurrence of supernumerary chromosomes. Its karyotype consists of 12 submetacentric, 4 subtelocentric and 3 telocentric chromosome pairs. The supernumerary chromosomes were easily distinguished by their reduced differentiated size and by their intra and inter-individual variability. C. edule is the first bivalve species where supernumerary chromosomes have been observed. V. ullustra had 2n = 38 with a karyotype including 3 metacentric, 8 submetacentric and 8 subtelocentric chromosome pairs. V. rhomboides had 2n = 38 with a karyotype including 4 metacentric, 8 submetacentric, 4 subtelocentric and 3 telocentric chromosome pairs. Cytotaxonomic relationships are proposed within Tapetinae from comparative analysis of karyotypes of two species studied here and three other species of the same subfamily previously studied

NERVOUS CONTROL OF CILIARY ACTIVITY IN GASTROPOD LARVAE

Volume: 151Start Page: 182End Page: 19