Banded karyotypes of three whales: Mesoplodon europaeus, M. carlhubbsi and Balaenoptera acutorostrata

The somatic chromosomes of two beaked whales, Mesoplodon europaeus and M. carlhubbsi, and one balenopterid whale, Balaenoptera acutorostrata, were studied. The chromosome number of the beaked whales is 2n = 42. The karyotypes are morphologically similar. Both species have a large X chromosome due to accumulation of C-heterochromatin. The karyotype of B. acutorostrata is in good agreement with the general 2n = 44 cetacean karyotype. The 2n=42 beaked whale karyotypes are presumed to have evolved from the general 2n= 44 karyotype through a fusion of two pairs.