Opisthobranch of the Week Data
Nembrotha guttata is considered to be very rare on Okinawa as I have seen and collected a total of only two specimens; the first during July of 1989 and the latest during May of 1992. The above featured animal was collected during a mid-day SCUBA excursion from a small coral reef depression on a vertical rock wall at the reef edge. As found, it was in a relatively tight ball on a small brown alga and the animal appeared to be damaged. I've added a second page with three additional images of the species; the first two images are of the same 11mm featured animal above; one of the images show secretions emitted by the animal as it was handled. The third image is of the only other collected specimen found here which was 22mm and had a major portion of its body, posterior to the gills, missing.
I've previously had this animal listed on the Okinawa page as an unknown Nembrotha sp. (now deleted), but a recent feature on the Sea Slug Forum (Rudman, 2001) has led me to believe this is N. guttata.
Erwin Köhler (2001) has several excellent images of N. guttata, from the Philippines on the Slug Forum, and closer to the main island of Okinawa, an image submitted by Kim Redlack (1999) from the Anami [sic] Islands (this probably has reference to the Amami Islands, ca. 150km NNE of Okinawa's main island).
The species was described by Nathalie Yonow (1993) from the Maldives and was described from a single specimen; most taxonomists would probably take a dim view of a new species being described from a single individual specimen, as there is no indication of the possible intra-specific variations. The Sea Slug forum is an excellent vehicle to illustrate these variations of many opisthobranch groups, including those seen in N. guttata.
Previously I've featured several members of the genus Nembrotha on these pages and as of the current date, there are several described and undescribed species reported from Okinawan waters. These featured animals are as follows:
N. guttata The above featured animal N. kubaryana N. lineolata N. livingstonei N. milleri N. species 1