The stress response of the highly social African cichlid Neolamprologus pulcher.

In group-living species, dominant individuals are frequently aggressive toward subordinates, and such dominant aggression can lead to chronic stress, higher glucocorticoid levels, and decreased fitness for subordinates. However, in many cooperatively breeding species, it is surprisingly the dominants rather than the subordinates that exhibit higher levels of glucocorticoids, a possible consequence of the demands of maintaining high social rank …