CETACEAN MITOCHONDRIAL-DNA CONTROL REGION - SEQUENCES OF ALL EXTANT BALEEN WHALES AND 2 SPERM WHALE SPECIES

The sequence of the mitochondrial control region was determined in all 10 extant species commonly assigned to the suborder Mysticeti (baleen or whalebone whales) and to two odontocete (toothed whale) species (t he sperm and the pygmy sperm whale). In the mysticetes, both the lengt h and the sequence of the control region were very similar, with diffe rences occurring primarily in the first almost-equal-to 160 bp of the 5' end of the L-strand of the region. There were marked differences be tween the mysticete and sperm whale sequences and also between the two sperm whales. The control region, less its variable portion, was used in a comparison including the 10 mysticete sequences plus the same re gion of an Antarctic minke whale specimen and the two sperm whales. Th e difference between the minke whales from the North Atlantic and the Antarctic was greater than that between any acknowledged species belon ging to the same genus (Balaenoptera). The difference was similar to t hat between the families Balaenopteridae (rorquals) and Eschrichtiidae (gray whales). The findings suggest that the Antarctic minke whale sh ould have a full species status, B. bonaerensis. Parsimony analysis se parated the bowhead and the right whale (family Balaenidae) from all r emaining mysticetes, including the pygmy right whale. The pygmy right whale is usually included in family Balaenidae. The analysis revealed a close relationship between the gray whale (family Eschrichtiidae) se quence and those of the rorquals (family Balaenopteridae). The gray wh ale was included in a clade together with the sei, Bryde's, fin, blue, and humpback whales. This clade was separated from the two minke whal e types, which branched together.