Gymnodoris amakusana

Photo taken at Mooloolaba Rockwall, Sunshine Coast, Australia
Photo courtesy of Gary Cobb

Gymnodoris amakusana (Baba, 1996)

Well this week the Sea Slug Site brings you a little taxonomic controversy. Gary and Dave Mullins came across this beauty on an incredible 3 Ĺ hour, double tank dive at the Mooloolaba Rockwall, on the Sunshine Coast of Australia. Gary IDíd the specimen as Analogium amakusanum . Not too far off. The species has now been moved to the genus Gymnodoris, and the species trivial name required a new ending.

As reported on Bill Rudmanís Forum this species was thought to be a color form of Gymnodoris striata , until Babaís description. Bill states here that he has found no anatomical reason to support this new species. I really not sure I agree, but who am I too say? If anyone knows his gymnodorids it Dr. Bill Rudman.

When I compare the two species externally I notice a number of differences. The problem is I donít know just how much variation there is for each of these characteristics. G. striata has several broken longitudinal stripes on the side of the body and on the dorsum, between the gill and rhinophores, where as G. amakusana has none. G. amakusana has a wide saddle of color across the dorsum immediately in from of the gill, never found in G. striata . In G. amakusana the gills are tipped with orange or yellow See Nakano , page 113, where G. striata has a line up the entire branch of each gill branch.

It is hard to say for sure who is right. This species is one of many my colleagues are in disagreement on. Currently G. amakusana is known from Hong Kong, Japan, New Caledonia and both coasts Australia.

Dave Behrens
Danville, Calif
Apr. 2005

Gary Cobb

I guess you could say I am an art director, graphic designer, illustrator, cartoonist, font designer, typographer, fine artist, web designer, diver and underwater photographer that moved from Los Angeles to the Sunshine Coast, north of Brisbane Australia, in 1990. In 1996 Gary and wife Jan launched Cobb Creative, a full service advertising and design studio

My first book, The Peak Baggers Guide to the Sunshine Coast was published in 1996 and my video Walking the Overland Track, Tasmania has been acclaimed as a must for anyone considering hiking this world heritage trail.

I was a skydiver/instructor for 15 years and after accomplishing all that I set out to do, Jan and I took up diving together. I have the tendency to get to the bottom and slowly work my way around searching for the beautiful little things occasionally catching a glimpse of something bigger gliding by. My mission is now to record the opisthobranchs of the Sunshine Coast. In two years, I and dive buddy David Mullins have recorded 180 species that can be viewed at Gary and David's nudibranch site. Nudibranchs of the Sunshine Coast , Australia.

I tend to refer to nudibranchs as Jewels of the Sea. My area of interest is from Moreton Island to Noosa. My favourite dive site is Old Woman Island off Mudjimba Beach. "The surrounding reefs of the island are a branchers paradise!" I find the night dives here are better than the Great Barrier Reef.

Greg Riddell of Sunreef Scuba Diving Services and I recently broke the Guinness World Record for Longest Submergence on a single tank of air for 7 hours 40 min 14 sec breaking the old record by 15 minutes.

My underwater camera gear is a Nikon Coolpics 5000 with a 512mb card (200 plus hires jpeg photographs), Subal housing, twin Inon strobes. You'll usually see me wearing twin scuba tanks on dives because redundency is important and 'dive time is picture time'. I just don't see the value of spending limited time underwater and taking a camera the only yields 36 shots that aren't guaranteed. You have more options with digital.

The Nikon Coolpics has an option called 'Optical Zoom'. I found it very difficult to use underwater...refused to focus at max zoom. I bought a 110mm magnifying glass and a piece of PVC pipe and attached it to the port of the housing. See attached. Underwater I take it off to flood the air out and walla! I have fast focussing. "Saga" was shot this way and I think it works great! The close up world is looking just fine. OH! Saga was just short of 10mm long. I also put a magnifier on the rear viewing window. See attached .

Send Gary email at

Puerto Vallarta, Mexico
March 2005

Ali Hermosillo and Dave Behrens

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

Send Dave mail at

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