November 27, 2009
From: Vishal Bhave
Concerning message #1121:
Locality: Okha, Gulf of Kutch, 10-40 cm, Gujarat, India, Arabian sea / Gulf of Kutch, Intertidal with lots of alga in small rock pools. Length: 12 mm. Photographer: Vishal Bhave.
Bhave, V.J., 2009 (Nov 27) Elysiella pusilla from Gulf of Kutch, India. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/22859
I have no doubt your animals are Elysiella pusilla. There is no 'biological' reason why it should be crawling on Sargassum but at times in tidepools animals leave their favoured places and crawl out over brown algae which often forms a fringe aroud the edge. I have often found sponge feeding dorids doing the same, often just before the tide turns and the water starts to return. It may be something to do with an internal rhythm or maybe by the end of low tide the water temperature or oxygen levels are causing discomfort.
But to return to Elysiella pusilla. As I discuss on page 2 of the Fact Sheet, this species can change shape from a very flattened animal to a quite cylindrical form. Your photos show both these forms.
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