Mitochondrial Sequence Variation in Carios capensis (Neumann), a Parasite of Seabirds, Collected on Torishima Island in Japan

Partial mitochondrial 16S ribosomal ribonucleic acid gene sequences in the ticks Carios capensis collected from black-footed albatross, Diomedea nigripes, colonies on Torishima Island, Japan (30°28′N, 140°18′E), were examined. The sequence was compared with those of C. capensis from Hawaii, South Carolina, and Texas. The sequences were all identical in ticks from Torishima and 2 from Hawaii. There were 2–3 transitions between the other Hawaiian and Texas ticks and Torishima specimens. Two transitions were also observed when compared with the ticks from South Carolina. The results suggest the possibility of gene flow between tick populations at each of the 2 geographic sites, which probably was accomplished by tick-infested migratory seabirds at their breeding sites. Sequence comparison analysis indicated that the C. capensis ticks are on the branch with C. marginatus and C. mexicanus ticks and not with Ornithodoros. This supports the revision suggested by Klompen and Oliver (1993).