Meeting Abstract

65.5  Sunday, Jan. 6  Systematic position of Thalassianthidae among sea anemones using mitochondrial and nuclear genes. CROWTHER, A.L.*; DALY, M.; FAUTIN, D.G.; Univ. of Kansas, Lawrence; Ohio State Univ., Columbus; Univ. of Kansas, Lawrence andreac@ku.edu

We infer from morphological data that sea anemones of the family Thalassianthidae form a monophyletic group: all species possess both dendritic tentacles and specialized defensive tentacles called nematospheres. Dendritic tentacles occur in the sea anemone families Phymanthidae and Actinodendridae, but nematospheres are unique to Thalassianthidae. However, other sea anemones possess specialized defensive structures (e.g. vesicles in Aliciidae and acrospheres in Actinodendridae) which have similar function and structure to nematospheres. Over 4Kb of new sequence data provided us with a molecular framework to investigate whether these defensive structures are homologous. We sequenced mitochondrial (12S and 16S) and nuclear (18S, ITS, and 28S) genes for multiple representatives of Thalassianthidae, Actinodendridae, Aliciidae and Phymanthidae. Relationships within major groups of sea anemones are poorly resolved; this study provided us with a preliminary placement of Thalassianthidae.