Meeting Abstract
59.9 Wednesday, Jan. 6 Behavioural and physiological responses of a wild teleost fish to cortisol and androgen manipulations during parental care DEY, C.J.*; O’CONNOR, C.M.; GILMOUR, K.M.; VAN DER KRAAK, G.; COOKE, S.J.; McMaster Univ., Hamilton, ON; Carleton Univ., Ottawa, ON; Univ. of Ottawa, ON; Univ. of Guelph, ON; Carleton Univ., Ottawa, ON cody.dey@live.com
It is widely accepted that the endocrine system plays an important role in the initiation and control of reproductive activities, including parental care. Despite an abundance of studies regarding this relationship, elucidation of the roles of each hormone in relation to specific behaviours has proven difficult. In some parental male fish, androgen hormones are critical in stimulating territory acquisition and nest-building behaviours but their role during parental care is more contentious. Likewise, glucocorticoids have been suggested to play a key role in mobilizing energy reserves required for energetically costly behaviours such as protracted brood care. This study investigated the role of androgens and cortisol in mediating parental care behaviours of the smallmouth bass using exogenous manipulations of hormone titers. Behaviours of parental fish treated with cyproterone acetate, an anti-androgen and those treated with cortisol were examined in the context of parental vigilance, aggressive nest-defence behaviours and nest success and compared to non-treated parental fish. Furthermore, plasma biochemical energetic and nutritional status indicators were measured and related to endocrine titers and parental behaviour. This study revealed that cortisol treatment resulted in a significant decrease in nest success, possibly due to the energetic cost of sustained levels of the hormone. Interestingly, cortisol treatment did not affect other parental care behaviours. In addition, cyproterone acetate treatment decreased nest defence aggression towards a simulated brood predator. Overall, these findings suggest an important role for both androgens and cortisol as proximate mediators of parental care in fishes.
