Scientists Find New Species of Sea Slug

Florida scientists have decided that a sea slug living in the Keys differs enough from its cousins elsewhere in the Caribbean to be considered a new species.

The lettuce sea slug in the Keys had been thought to be Elysia crispata, a species identified in 1863. But scientists from the University of South Florida have found significant differences in its morphology and DNA.

The new species has been named Elysia clarki, in honor of the late Kerry B. Clark, biologist and professor at the Florida Institute of Technology.

The differences between E. crispata and E. clarki exist at every level, said Skip Pierce, chairman of the Department of Biology at the University of South Florida. There are morphological, developmental, feeding and molecular differences, and very important habitat differences.

Scientists say E. clarki may be unique to the Keys. The sea slugs live in mooring canals and borrow pits, in very shallow water.