Another soft coral species found in Bermuda: Leptogorgia setacea

Photograph of Leptogorgia setacea in its natural environment (credit: J.P. Bilewitch and L.P. Holland).During a routine benthic survey dive in Great Sound in August 2008, Drs. Sarah Manuel and Kathy Coates (Department of Conservation Services) found what looked like very thin, broken tree branches lying on the sea bottom at about 55 feet depth. A much closer look showed there were tuft-like bodies, called polyps, sticking out from the branches, and that this was a soft coral (Octocorallia). Using a combination of body structure and gene sequences this was identified as the species Leptogorgia setacea*, but it has been nicknamed the “tumbleweed coral”. Leptogorgia setacea is also known to occur along the east coast of the United States and along the coast of the Northern Gulf of Mexico. It is usually found at depths less than 30 m (about 100 feet)., similar to where it was found in Bermuda.

This is the first record of a new-to-Bermuda shallow-water soft coral species to be made in more than 30 years. Genetic studies may show whether it has just recently become established in Bermuda or whether it is a long-time resident and has just gone un-noticed.

*Bilewitch, Jaret P., Lyndsey P. Holland, Kathryn A. Coates and Sarah A. Manuel. (manuscript in preparation for publication). A new record for Bermuda expands the distributional limit of the azooxanthellate octocoral Leptogorgia setacea.

Close ups of a branch and of an individual polyp of L. setacea (credit: J.P. Bilewitch and L.P. Holland).

Scanning electron micrographs of two types of calcareous spicules (sclerites) from the branches of L. setacea (credit: J.P. Bilewitch).