It was believed that epigean and hypogean Astyanax differ markedly in their display of agonistic behavior. Research suggested that surface-dwelling individuals were extremely aggressive whereas their blind, cave-dwelling counterparts tended to show little or no aggressive behavior. Aggression in Astyanax was thought to be triggered by visual stimuli because surface fish in a dark environment or surface fish blinded late in life did not show aggression. They demonstrate that surface fish blinded early on in their embryonic development are highly aggressive as adults. They also report the first case of a population of blind cave-dwelling Astyanax that is highly aggressive. They conclude that reduced aggression is not the only evolutionary pathway for troglobitic Astyanax and that there is some degree of developmental plasticity in the releaser of aggression and in the selection of its triggering stimuli.
Espinasa, L., Yoshiyuki Yamamoto & Jeffery, W.
Behavioural Processes Volume 70, Issue 2 , 30 September 2005, Pages 144-148
Behavioural Processes Volume 70, Issue 2 , 30 September 2005, Pages 144-148
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