Solar-powered jellyfish from the Philippines

Dear carlos,

I am not very good at keeping to my promise to deal only with sea slugs - what with sea pens from Western Australia [#17207] and sea anemones from Marseille [#17197], now we have a solar-powered jellyfish. This amazing animal, Cassiopeia andromeda, swims, floats or rest on the bottom upside down, so that its fleshy 'arms' or 'tentacles', which are packed full of single celled zooxanthellae, get the optimum amount of sunlight for photosynthesis. See the Fact Sheet on Solar powered sea slugs for background information.

Whenever I find these jellyfish I  search them for aeolid nudibranchs, because they seem to be an ideal food. So far I have had no luck in the Indo-West Pacific, but in 1985, Brandon and Cutress described a species, Dondice parguerensis, from a Caribbean species of Cassiopeia. I was at the time working on solar powered nudibranchs so I was interested in knowing if D. parguerensis was taking the zooxanthellae from the jelly fish and re-using them itself. Unfortunately I couldn't tell from the specimens they sent me, but more recently Dave Behrens has sent photos of that species and it seems they don't. However I still think its worthwhile having a look at this jellyfish in the Indo-West Pacific for an aeolid. There is nothing to say there isn't one recycling zooxanthellae in the Pacific.

Best wishes,
Bill Rudman