Karyotypes and idiograms of sperm and pygmy sperm whales

Abstract

The somatic chromosomes of the sperm whale, Physeter catodon L. and the pygmy sperm whale, Kogia breviceps Blainville, were studied. The chromosome number of both species is 2n=42. The sperm and pygmy sperm whales are the only cetaceans, so far recorded, with a chromosome number deviating from 2n=44. The karyotypes of the two species studied are entirely different from the general cetacean karyotype. © 1973 Mendelian Society of Lund