Burch and Huber 1966

Burch JB, Huber JM. 1966. Polyploidy in mollusks. Malacologia 5: 41-43.

These authors present a very brief summary of examples of polyploidy discovered to date among molluscs. The conditions promoting or presumed necessary for polyploidy in animals are first presented; of chief importance is the ability to physiologically and developmentally tolerate increased chromosome numbers and the ability to either self-fertilize or reproduce parthenogenically.

Among known selfing-capable hermaphroditic molluscs, the family Lymnaeidae has no examples of polyploids among the 40 species studied. There are unconfirmed reports of polyploidy in other families, including the land snails Succineidae and the freshwater clams Sphaeriidae (see also the much more recent Lee and O Foighil, 2002). The authors suggest that most of the observed variation in molluscan chromosome numbers can be attributed to aneuploidy, an hypothesis I find unlikely in light of more recent understanding of genome organization, especially the role of chromosome fissions, fusions, and translocations in structuring genomes.