Nembrotha sp.

Photo courtesy of Jeff Rosenfeld
Batangas, Philippines
April, 1999

Nembrotha sp.

Isn't this newly discovered species from the nudibranch gold mine called Batangas, Philippines, a beauty? While it would be convenient and comforting to be able to put an identification on it, we can't!

Recently a number of our friends and colleagues have shared photographs and observations of a similarly colored group of phanerobranch dorids, belonging to the families Polyceridea and Gymnodorididae. These species, like Jeff's animal shown here are nembrotha-like in external anatomy, with some variation of large round spots and wide spreading gills.

At first I thought this species might be Gymnodoris aurita (Gould, 1852) recently redescribed by Gosliner and Behrens (1997) and similar to Nembrotha? Sp.10 on the Sea Slug Forum. Each of these species is orange to orange-brown with lighter, cream to yellow spots. Differences appear in the coloration of the gills and rhinophores.

In our redescription of Gymnodoris aurita we comment on the photo presented in Wells & Bryce (1993, fig. 98) for this species, noting its dissimilarity with the original description of G. aurita. Debelius (1998, pg. 180) lists Wells & Bryce's species as Nembrotha livingstonei Allan, 1933, however it bears little similarity to the series of photos shown on Bill Rudman's Sea Slug Forum for this species. Rudman suggests that N. livingstonei can be best distinguished by a white cross-like patch between the rhinophores and around the gill pocket.

The situation is further complicated by a series of darker color specimens on Rudman's site following the same light on dark, orange spotted coloration. Specimens from this latter series are being examined closely and may provide some real taxonomic surprises. Other sightings by Douglas Hoffman in the Lembah Straits, Indonesia adds to a growing dilemma.

In any event, over the past 10 years and hundreds of dives in this very locality, we have not discovered the species Jeff shares here. GREAT FIND JEFF!!! We hope to be able to return to Batangas and find this critter once again in order to take a close look at its internal anatomy to determine where it fits into the taxonomic confusion presented above.

By vocation, Jeff Rosenfeld is the Technology Coordinator for a high school in Seattle, Washington. In his spare time, he loves to travel. Jeff began diving in 1994 and taking underwater photos in 1995. Among his favorite destinations are the Philippines, Solomon Islands, Indonesia, and a bit closer to home, Vancouver Island. Jeff maintains a web site of his underwater photography called The Vibrant Sea.

Send Jeff email at

Taxonomic information courtesy of Dave Behrens

David W. Behrens

Author: Pacific Coast Nudibranchs
Co-Author Coral Reef Animals of the Indo Pacific
Propriator of Sea Challengers Natural History Books !

Send Dave mail at

© The Slug Site, Michael D. Miller , 1999. All Rights Reserved.