Sexual conflict in simultaneous hermaphrodites: evidence from serranid fishes

Synopsis Much of modern mating systems theory is founded on the assumption that a conflict of interests between males and females acts to shape reproductive strategies. If sexual conflict exists it should extend to simultaneous hermaphrodites. Here, the suggestion is made that hermaphrodite mating systems can be used to explore the assumptions associated with sexual conflict and (a) predictions about hermaphrodite mating systems, and (b) a comparative analysis of the mating systems described for a group of species of simultaneously hermaphroditic serranid fishes. Theories based on Bateman's principle predict that there should be a preferred role in hermaphrodites; i.e. the male role ought to offer potential fitness advantages to all serranids and serranid mating systems reflect this. The comparative analysis offers evidence that cheating in the male role is found in all of the species studied and explains the harem polygyny system of two species. This preference for the male role in this group offers the best evidence currently available for the existence of sexual conflict as a factor shaping mating systems.