THE PHYLOGENY OF OPHRYOTROCHA (DORVILLEIDAE, EUNICIDA, POLYCHAETA)

The phylogeny of 20 cultured species of Ophryotrocha, including a grou p of sibling species that can only be identified by biochemical or rep roductive information, is estimated from a combined parsimony analysis of 32 morphological, reproductive and electrophoretic characters, wit h selected members of Dorvillea, Ougia and Protodorvillea used as outg roups. Sexual production in the group include simultaneous hermaphrodi tism, protandrous sex reversal, an exceptional male/hermaphrodite syst em, and gonochorism. According to the presented phylogeny, simultaneou s hermaphroditism appears as the primitive state in the group. It is s uggested that sequential hermaphroditism and gonochorism are independe ntly acquired, the latter state also giving rise to the male/hermaphro dite system.