Abstract
Mitotic and meiotic chromosomes from the gonads of the freshwater gastropod, Lymnaea luteola Lamarck, family Lymnaeidae have been studied. The 2n=34 and n=17 were confirmed from the spermatogonial and meiotic metaphases respectively. All the chromosomes were found biarmed with median or submedian position of their centromeres. Allocycly has been observed among the chromosomes at different meiotic stages. The differences in the morphology of the chromosomes of the same species reported earlier have been pointed out. Chromosome number conservatism at the confamilial and congeneric level of the order Basommatophora with the tendency towards an increase in the chromosome number have been discussed.
