Melibe from sthn Queensland

Note added 22 October 2008: I am pretty sure this is Melibe japonica. See messages #21985, #21984.

Dear Colleen,
As I should be saying to everyone at the moment, sorry it's taken a while to reply but better late than never.

This is a species of Melibe which are amazingly shaped nudibranchs whose head has evolved into a large 'fishing net' which they use to catch and eat small crabs and shrimps. There is a species on the west coast of Nth America, M. leonina, which hangs on to the large kelp plants which grow there and stretches it 'fishing net' out into the water current to catch small plankton. Although most species are able to swim, like your was doing, they usually crawl around on the bottom with their net wide open feeling for small crustacea with the fine tentacles around the 'lips' of the net. I have never seen one with the pink patches in the 'net' which we can clearly see in your photo alongside. The skin their is very thin so I can't say whether the pink patches are lumps of tissue [glands perhaps?] in the skin or whether they are lumps of food? which the Melibe has collected from the water. Perhaps its is collecting small plankton as it is swimming around. Since I have never seen such lumps before I can only make a wild guess at what they are.

To get an idea of the shape and variety found in this group of sea slugs use the menu list on the top left of the page to go to the Taxonomic Search page and search for Tethydidae. It will take you to a list of Fact Sheets on different species of Melibe and its relatives. If you look at those pages, and the messages attached, you will find a lot of information on the group. Unfortunately from your photos I can't see enough detail to identify exactly which species you saw, but it was most probably Melibe viridis.

Best wishes,
Bill Rudman