February 5, 2009
From: Marcel Tanke
Concerning message #10912:
On our trip to Thailand, Ademan Sea, Phi Phi- and Similan Islands I found several Aldisa williamsi. The first picture here shows one laying red eggs, a color that I did not expect from a bluish / white / black animal.
Interesting colors variations: picture 2 shows some yellow postules and picture 3 shows one yellow pustule and maybe some yellow color on the edge of the mantle.
I am sending 3 Other regular (?) specimens in a separate message [#22214 ].
Locality: Phi Phi and Similan islands area's, 10-15 meters, Thailand, Ademan Sea, January 2009. Length: about 2 cm. Photographer: Marcel Tanke.
Tanke, M.A., 2009 (Feb 5) Aldisa erwinkoehleri from Thailand, laying red eggs . [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/22213
This is a similar species Aldisa erwinkoehleri which has this forked black pattern on the mantle and some yellow pustules. The red egg string is interesting. Perhaps it is a clue that the bright red sponge near the animal in the lower photo is their food? Quite a few species of Aldisa are red and feed on red sponges.
Aldisa erwinkoehleri from Thailand 
From: Marcel Tanke, February 5, 2009
Aldisa erwinkoehleri from the Andaman Sea
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Another amazing phyllidiid mimic
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