Fighting cichlids: morphometric and hormonal analysis to understand female and male aggression.

VANCE TRUDEAU; MARIA FLORENCIA SCAIA; MATIAS PANDOLFI; SOMOZA, GUSTAVO MANUEL

Konstanz

Congreso; ASAB Summer meeting; 2019

Association for the Study of Animal Behaviour (ASAB)

Even though aggressionin males has been historically linked to androgens, recent evidences suggestthat the key step regulating this behavior involves aromatization to estrogens.Even if females from different species also display aggressive behavior,aggression has been usually studied in males competing for resources and femaleaggression is still understudied. The challenge hypothesis suggests thatbehavioral interactions lead to an increase in plasma androgen levels inresponse to social instability. Cichlasomadimerus is a monogamous Neotropical cichlid with bi-parental behavior, inwhich both males and females show aggressive behavior. In this context, theaims of this study were: a) to perform network correlation analysis ofmorphometric and hormonal variables in order to understand individualvariability in aggressive behavior; b) to determine whether there is arelationship between sex steroids plasma levels and intrasexual aggression inthe context of the challenge hypothesis. Sex steroids were determined beforeand after intrasexual dyadic agonistic encounters and morphometric variableswere measured. All agonistic interactions were recorded for one hour andaggressive and submissive displays were determined in each animal. Networkcorrelation analysis suggests that morphometric and hormonal variables can differentiallyexplain individual aggression not only in males but also in females. Moreover,initial estradiol plasma levels can predict winner status and aggression infemales, but not in males. Finally, during male encounters there was not onlyan increase in androgen levels but also in estradiol levels, suggesting thatthe challenge hypothesis could be extended to estrogens.