MITOCHONDRIAL-DNA VARIATION IN ATLANTIC AND PACIFIC WALRUSES

We used restriction enzyme analysis of polymerase chain reaction ampli fied mitochondrial DNA to assess genetic differentiation of two subspe cies of walruses: Atlantic walruses (Odobenus rosmarus rosmarus) from Greenland and Pacific walruses (O. r. divergens) from the Chukchi Sea. Each subspecies has distinct monophyletic mitochondrial DNA haplotype s. Mitochondrial DNA sequence divergence between Atlantic and Pacific subspecies was 1.0-1.6%. Several haplotypes were observed for each sub species. Haplotype frequencies varied among sampling locations of Atla ntic walruses, suggesting that mitochondrial DNA may be useful for wal rus stock identification.