The phylogeny of Ophryotrocha (Dorvilleidae: Eunicida: Polychaeta)

The phylogeny of 20 cultured species of Ophryotrocha, including a group of sibling species that can only be identified by biochemical or reproductive information, is estimated from a combined parsimony analysis of 32 morphological, reproductive and electrophoretic characters, with selected members of Dorvillea, Ougia and Protodorvillea used as outgroups. Sexual production in the group include simultaneous hermaphroditism, protandrous sex reversal, an exceptional male/hermaphrodite system, and gonochorism. According to the presented phylogeny, simultaneous hermaphroditism appears as the primitive state in the group. It is suggested that sequential hermaphroditism and gonochorism are independently acquired, the latter state also giving rise to the male/hermaphrodite system.