Cytological studies of archachatina marginata and achatina sp. From southwestern Nigeria

Abstract

African giant snails, Archachatina marginata and Achatina sp. were examined cytologically with the aim of determining their chromosome numbers. The chromosome numbers were 2n=56 and 2n=44 for A. marginata and Achatina sp. respectively. Using the metaphase spreads of meiosis 1 in the ovotestes tissues of the snails, 28 and 22 bivalents were observed for A. marginata and Achatina sp. respectively. The chromosomes were large and rod like. Prometaphase and mitotic metaphase stages were also recorded for A. marginata while only mitotic metaphase stages were recorded for Achatina sp. The chromosomes at these stages were reduced in size. This could probably be an intrinsic feature of these species. No polyploidy was observed in all the cells examined. (Tropical Veterinarian: 2002 20(2): 74-79)