Information in the books and on the Internet is rather sparse regarding the Thecacera genus. There's not much I can tell you other than my own experiences as a marine naturalist. I have seen it predominately on sandy substrates but those observation's do not preclude its being on on other substrates where food may be the predominant reason for its presence. A short video has been prepared in *.flv format of a sister species feeding on what appears to be arborescent bryozoan . Many years ago when I collected a specimen on a night dive and kept it over till morning to take it the for additional photography. Much to my chagrin, the specimen could not be initially located in the collection bucket. After careful examination (I mean after all, where could it go??), the specimen was found to have shriveled to the size of a small pea (maybe smaller). Once back in the ocean the next day, it slowly re acquired its original size! The case of the disappearing branch! Isn't nature amazing??
Peri, and my life long diving buddy Jerry Allen relaxing between dives
Club Ocellaris, May 2006
Peri has been acting as a dive guide in the Philippines for about ten (10) years now. When he's not doing that he does Wedding Photography on the side. Peri ranks very high on my list
of dive guides in the PI that can find seldom seen sea slugs. As you can see from the above image, Peri is an excellent photographer (even when using someone else's equipment). Peri is very
good at recognizing and capturing the scene so as to say. Last April while relaxing on the veranda at Club Ocellaris, I noticed Peri go get his camera and wade out into the water to photograph
one of the staff fishing. I wondered what was going on and then I saw what Peri was after and I ran and got my Sony HD Camcorder and took video of Peri photograhping the fisherman against a setting
sun. This footage was later blended into a video that made the final cut into our San Diego Underwater Photographic Society film festival! Imagine that! Slugs are coming into their own for sure!
This video file is about 60 megs, so you will need a broadband connection and the latest version of quicktime to view it!