Effects of maternal cortisol treatment on offspring size, responses to stress, and anxiety-related behavior in wild largemouth bass (Micropterus salmoides)

• Published in: Physiology & behavior Vol. 180; pp. 15 - 24
• Main Authors: Redfern, Julia C., Cooke, Steven J., Lennox, Robert J., Nannini, Michael A., Wahl, David H., Gilmour, Kathleen M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.10.2017
• Subjects: Aggression; Aggression - drug effects; Analysis of Variance; Animals; Animals, Newborn; Anxiety - drug therapy; Bass - physiology; Behavior; Body Size - drug effects; Boldness; Cortisol; Disease Models, Animal; Dose-Response Relationship, Drug; Embryo, Mammalian; Exploration; Exploratory Behavior - drug effects; Female; Hydrocortisone - pharmacology; Intergenerational effects; Largemouth bass; Male; Maternal Exposure; Maternal stress; Reaction Time - drug effects; Reproduction - drug effects; Stress response; Stress, Physiological - drug effects; Swimming; Thigmotaxis; Largemouth bass; Maternal stress; Aggression; Exploration; Cortisol; Behavior; Stress response; Intergenerational effects; Thigmotaxis; Boldness
• ISSN: 0031-9384; 1873-507X
• DOI: 10.1016/j.physbeh.2017.08.001

Cortisol, the main glucocorticoid stress hormone in teleost fish, is of interest as a mediator of maternal stress on offspring characteristics because it plays an organizational role during early development. The present study tested the hypothesis that maternal exposure to cortisol treatment prior to spawn affects offspring phenotype using wild largemouth bass (Micropterus salmoides). Baseline and stress-induced cortisol concentrations, body size (i.e. length and mass), and behavior (i.e. anxiety, exploration, boldness, and aggression) were assessed at different offspring life-stages and compared between offspring of control and cortisol-treated females. Cortisol administration did not affect spawning success or timing, nor were whole-body cortisol concentrations different between embryos from cortisol-treated and control females. However, maternal cortisol treatment had significant effects on offspring stress responsiveness, mass, and behavior. Compared to offspring of control females, offspring of cortisol-treated females exhibited larger mass right after hatch, and young-of-the-year mounted an attenuated cortisol response to an acute stressor, and exhibited less thigmotaxic anxiety, exploratory behavior, boldness and aggression. Thus, offspring phenotype was affected by elevated maternal cortisol levels despite the absence of a significant increase in embryo cortisol concentrations, suggesting that a mechanism other than the direct deposition of cortisol into eggs mediates effects on offspring. The results of the present raise questions about the mechanisms through which maternal stress influences offspring behavior and physiology, as well as the impacts of such phenotypic changes on offspring fitness. •Female wild largemouth bass were treated with cortisol prior to spawn.•The acute cortisol response was attenuated in offspring of cortisol-treated females.•Offspring of cortisol-treated females were less bold, exploratory, aggressive and anxious.•Thus, maternal stress in bass appears to “program” offspring stress responses and behavior.