Trying to identify this giant slug species.

July 14, 2006
From: Walter D'Alonzo

I'm trying to identify the slug species in this picture. I realize that it isn't a great photo, so I will provide some additional information. My dive buddy and I found these slugs all over the sea floor in sandy, flat areas. They seemed to be inhaling sand and filtering it. They were radially symmetrical and cylindrical with no obvious protrusions. They didn't respond when picked up, though they were obviously alive. There were two variations, one was predominantly white with contiguous dark grey splotches, as pictured, while the other slugs were identical but were predominantly dark grey with white splotches. Any help would be appreciated in ID'ing these creatures. I wasn't able to find anything similar in your species list.

Locality: Island, 30-50 feet, Runaway Bay, Jamaica, Atlantic Ocean, Mid June 2006, sandy bottom. Length: Appx. 1 foot. Photographer: Stephen Werner.

Walter D'Alonzo

D'Alonzo, W.M., 2006 (Jul 14) Trying to identify this giant slug species.. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Walt,
These are 'sea slugs' only in a very general sense. The true sea slugs are all molluscs - snails that have either lost their shells in their evolution, or are in the process of doing so. Your 'sea slugs' are more commonly called 'sea cucumbers' and the radial symmetry you describe is a clue to their real relationship, which is to sea stars and sea urchins and other echinoderms, which all show radial symmetry.
Best wishes,
Bill Rudman

Rudman, W.B., 2006 (Jul 14). Comment on Trying to identify this giant slug species. by Walter D'Alonzo. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from


Sea cucumbers

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