Social determination of sex in reef fishes.

Many fishes living in reef environments display remarkable flexibility in sexuality with social interactions determining their sex either during juvenile development or in adulthood. The evolutionary advantages of such flexibility are relatively well established. By contrast, the mechanisms by which social cues guide development of the sexual phenotype are less well understood. This paper reviews our understanding of these processes for some well-studied reef fish groups at the gonadal and neuroendocrine levels as well as proposing promising directions for future study.