The interrenal gland in males of the cichlid fish Cichlasoma dimerus : Relationship with stress and the establishment of social hierarchies

Highlights • The interrenal gland was exclusively located in the posterior portion of the cephalic kidney. • Nuclear area of interrenal steroidogenic cells differed between males of two distinct social ranks. • Cortisol and 11-ketotestosterone plasma levels differed between males of two distinct social ranks. • Cortisol plasma levels correlated positively with the nuclear area of interrenal steroidogenic cells. • For the first time, interrenal gland, cortisol plasma levels and social rank were studied together.