A Preliminary Study of Chromosomes of Two Species of Oysters (Ostrea lurida and Crassostrea gigas)

Abstract

A diploid chromosome number of 20 (n = 10) was found for each of the native oyster Ostrea lurida, and the Pacific oyster Crassostrea gigas. The diploid comple -ments of the native oyster were normal but in the Pacific oyster atypical numbers, polyploid nuclei, and abnormal cleavage was observed in some somatic metaphase plates. The diplotene meiotic bivalents of the native oyster resembled lampbrush chromosomes.