Gymnodoris sp. e149

When we first found this species, we thought it might be a form of Gymnodoris okinawae, which we had previously seen in Hawaii. However, the radula is quite different; in particular, the longest teeth of the Marshall Islands animals are in the middle of the half row rather than increasing in length to the outermost, as in the Japanese and Hawaiian G. okinawae (Baba, 1936; Kay & Young, 1969). At least 20 specimens have been observed at Enewetak and Kwajalein Atolls ranging in length from 7 to 25mm. They live on a variety of lagoon and seaward reefs at depths of 3 to at least 15 meters.

One external difference from G. okinawae is the distinct arrangement of orange spots forming a network around the low white pustules. In G. okinawae (see the bottom of this page), the orange spots and sometimes short lines are more randomly scattered over the dorsum.

Another difference with Gymnodoris okinawae is in the diet. Gymnodoris okinawae is reported by Kay & Young (1969) to eat various species of the sacoglossan genus Elysia. Gymnodoris sp. e149 was not interested in Elysia spp offered in the lab, but would readily eat small cephalaspideans as in the photo below.

For comparison, a photo of a Hawaiian Gymnodoris okinawae with its egg mass is provided below.

References:

Baba, K. 1936. Opisthobranchia of the Ryukyu (Okinawa) Islands. Journal of the Department of Agriculture, Kyushu Imperial University 5(4):1-49.

Kay, E.A. & D.K. Young. 1969. The Doridacea (Opisthobranchia; Mollusca) of the Hawaiian Islands. Pacific Science 13(2):172-231.

Created 1 January 2007
Updated 26 November 2007