Social control of reproduction in Cichlasoma dimerus: dominance, social isolation and agonistic interaction between non-dominant individuals.

FELIPE ALONSO; LEONEL MORANDINI; RENATO MASAKI HONJI; RENATA GUIMARÃES MOREIRA; MATIAS PANDOLFI

Buenos Aires

Simposio; 7th International Symposium on Fish Endocrinology; 2012

CONICET _ Agencia

In cichlid fish most studies on group living strategies and related physiology had focused on differences between dominant(D) and subordinated(S) individuals without exploring differences among the last. In this work we studied the correlation of physiological parameters with different social status: a) D and S males(m) in a stable colony, b)Socially isolated Dm and Dm in a stable colony, c)Sm and females(f) before social status ascent. Dm in a stable colony showed higher concentrations of 11-ketotestosterone but no differences in their gonadosomatic indexes compared to Sm of the same colony. They also showed lower concentrations of cortisol (C) and lower nuclear area of steroidogenic interrenal cells. Sm or Sf higher in the linear social hierarchy always ascends in social status when the opportunity is given. Sm higher in social hierarchy showed more relative gonad weight, and FSH pituitary content and lower plasmatic concentrations of C compared with S males lower in hierarchy. S females did not show differences in the selected physiological parameters. These results suggest that these animals anticipate social status ascent opportunity by gonad investment, with C probably mediating gonad development inhibition in lower ranked and socially isolated individuals.