Thecacera sp. 7

Image courtesy of Marcel Tanke
Mabul-Sipidan, Malaysia

Thecacera sp. 7 Undescribed (in Indo-Pacific Nudibranchs)

This wacky looking Thecacera can be found on page 111, of Indo-Pacific Nudibranchs and Sea Slugs as the 7th of seven undescribed Thecaceras reported there. On the Sea Slug Forum it is listed as Thecacera sp.1 Marcel's photograph clearly shows the characteristic body coloration of a mix of black and yellowish spots, and the red sub-apical ring on the oral tentacles, rhinophores, extra-rhinophoral process and its extrabranchial processes. In IPN we use Bernie Picton's photo from the Sea Slug Forum taken in Sulawesi, Indonesia. Marcel's specimen expands our known geographic range to include Mabul, Sipidan Island, Malaysia. Unfortunately, neither photo gives us a hint about this species prey bryozoan. I guess we will need to wait for the next sighting to figure that out.

Dave Behrens
Gig Harbor, Washington
Mar., 2010

Marcel and wife Marion

Marcel and Marion presently live in the Netherlands. My wife Marion and I started diving in the 14 years that we lived in China and Korea. Marcel has BSAC Instructor level. Diving took us all over Asia. Nudibranchs became our main interest after several trips to the Philippines and Indonesia. Marion is “spotter” for the nudibranchs and Marcel takes the pictures.

Last year, our expat life finished and we moved back to the Netherlands. As the North Sea water is cold and visibility low, we went for Christmas 2009 back to Asia, Malaysia - Mabul / Sipadan. Where we had the encounter with an undescribed Thecacera sp.:

In Mabul we had seen several, mainly orange and black colored, Thecacera species of what Bill Rudman on his website calls Thecacera sp. 2 . It was December 24, Christmas Eve. Our dive guide looked at a picture of the orange - black Thecacera , laughed and said: "I will show you the Christmas version of this orange nudibranch". He mentioned that the one we would be looking for, was wearing a red and white Christmas cap. At that moment, we did not really understand what he meant. The next dive, at Kapalay home reef, he swam straight to a place at the wooden artificial reef and showed us some some specimen of what Bill Rudman calls T. sp.1. Now we understood the “red and white cap”! We later that week again saw some of these nudibranchs, at the same location. We kept calling it the "Christmas nudibranch". J

I am still using the “point and click” Canon Ixus 900TI Digital Camera

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Webmaster's Notes: Stay tuned folks! Thecacera sp. 1 will run in two weeks!

From left to right, Terry Gosliner, Angel Valdes, Dave Behrens La Jolla, Calif.

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