The Distribution of Tigroid Fundus in Japanese Macaques (Macaca fuscata and Macaca fuscata yakui)

Abstract

The tigroid fundus is one of the unique characters of Japanese macaques distributed from the north of the Japanese main island, Honshu, to Yaku-shima Island in the East China Sea, south of Kyushu Island.

The ocular fundi of over 360 monkeys living at ten points around the country were photographed and compared.

In the Mann-Whitney U-test, the Yaku macaque, a subspecies of the Japanese monkey, showed a typical, heavy tigroid fundus. The incidence of this character in the Yaku monkey showed significant difference from that of other groups in main islands (p<0.01). The other monkey groups did not have such a strong incidence of tigroid fundi. However, the incidences of the Hakusan group on the Japan Sea side and that of the Hagachi monkeys on the Pacific Ocean side were different significantly (p<0.05) from each other.