A new species of the sea anemone Megalactis (Cnidaria: Anthozoa: Actiniaria: Actinodendridae) from Taiwan and designation of a neotype for the type species of the genus

Megalactis comatus, new species, from Taiwan is the third species in this genus of sea anemones with highly branched tentacles. The others are M. hemprichii Ehrenberg, 1834, from the Red Sea, and M. griffithsi Saville-Kent, 1893, from the Great Barrier Reef. Size of nematocysts from acrospheres and column clearly separate M. comatus from the other species of Megalactis. One of us (A.A.) observed asexual blastulae in M. comatus. This is the first record of asexual reproduction in the genus. Because type specimens of M. hemprichii have not been found and the original description cannot be used to distinguish this species from other species of Megalactis, we designate a neotype for the type species of the genus, M. hemprichii Ehrenberg, 1834. All the specimens of actinodendrids examined lacked basilar muscles; this calls into question the placement of family Actinodendridae among thenarian sea anemones.