Three male anomalously white Risso's dolphins Grampus griseus were observed in the waters off Taiji, Wakayama, Japan. One (GG-1) was captured alive in 2007, and the other two (GG-2 and GG-3) were captured in 2014. The color pattern of GG-1 is approximately divided into two parts; the middle of the trunk and the lower part of the dorsal fin are white, whereas the anterior and caudal portions have dark pigmentations. GG-2 has an almost white body with some dark pigmentation in the head region, and GG-3 has a completely white body with some sparse dark flecks around the throat. All three dolphins have dark eyes similar to a normally pigmented Risso's dolphin; however, the oral mucosa of GG-2 and GG-3 and the mucosa in the blowhole of GG-3 are white to pinkish in color without any dark pigmentation. Furthermore, the mucosa in the blowhole of GG-2 is a mixture of white patches and dark pigmentation. These three dolphins are the first anomalously white Risso's dolphins to be kept in captivity; therefore they are valuable for understanding the cause of body color variations and the anomalous coloration effects in animals.
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1 September 2017
Three Cases of Anomalously White Risso's Dolphins Grampus griseus in Japan
Noriko Funasaka,
Tetsuo Kirihata,
Masayuki Hosono,
Hidehiro Kato,
Seiji Ohsumi
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Mammal Study
Vol. 42 • No. 3
September 2017
Vol. 42 • No. 3
September 2017
Albino
anomalous white coloration
Japan
leucistic
Risso's dolphins