Meeting Abstract

P2.120  Friday, Jan. 4  Shell-forming sea anemones from Australia. CROWTHER, A.L.*; FAUTIN, D.G.; Univ. of Kansas, Lawrence; Univ. of Kansas, Lawrence andreac@ku.edu

Sea anemones of the genus Stylobates (Cnidaria: Anthozoa: Actiniaria) form obligate symbioses with hermit crabs. Three species of Stylobates have been described: S. cancrisocia from east Africa, S. aeneus from near Hawaii and Guam, and S. loisetteae from north-west Australia; we have examined specimens from north-eastern Australia in the Coral Sea. Studies of morphology should determine if these specimens are members of a new species, or extend the range of a known species. This exclusively deep-sea genus of anemone possesses the ability to produce a carcinoecium, a chitinous secretion that coats and extends the hermit crab�s shell. As most hermit crabs grow, they must relocate to larger shells. Stylobates can extend its carcinoecium as rapidly as the crab grows; thus the crab need not change shells. The deep-sea habitat of Stylobates has made natural history observations difficult. By analogy with other anemones that associate with hermit crabs, such as Calliactis, benefits for the crustacean may be protection, and benefits for the anemone may include transport for the otherwise-sessile anemone, and being able to feed from scraps when the crab feeds.