Morphology and phylogeny of the sea anemone Stichodactyla haddoni (Cnidaria: Anthozoa: Actiniaria) from Chabahar Bay, Iran

Abstract

Carpet anemones of the genus Stichodactyla are characterized by having no calcium carbonate skeleton, being flattened with rather short tentacles, being exclusively tropical, and being hosts for clown fish species. Most of the species belonging to this genus, however, are often very similar morphologically; thus, identification by external features is rather difficult. In this study, we have described the morphology and phylogenetic affinities of a carpet anemone species collected from Chabahar Bay. Although the Iranian species showed different coloration patterns within the same geographical area, they strongly resemble Stichodactyla haddoni Saville- Kent, 1893 in having short tentacles densely covering the undulated oral disc and white, pointed, recognizable exocoelic tentacles. Comparison of 18S rDNA with other actiniarians revealed that the 2 Iranian species are closely related to Stichodactyla haddoni, Stichodactyla gigantea, and Heteractis magnifica. This is the first record of Stichodactyla haddoni from the southeastern coast of Iran and the northern part of the Sea of Oman.