Regulation of Trade-Off Behaviors in a Mouthbrooding Cichlid Fish


Meeting Abstract

101-2  Wednesday, Jan. 6 13:45  Regulation of Trade-Off Behaviors in a Mouthbrooding Cichlid Fish O’ROURKE, C.*; RENN, S.C.P.; O’ROURKE, Cynthi; Reed College; Reed College kickseine@gmail.com http://academic.reed.edu/biology/professors/srenn/

Trade-offs between fundamental life history traits strongly influence fitness, and yet the molecular mechanisms underlying trade-off behaviors – for example decreases in somatic maintenance that allow for increases in reproductive output – are rarely explicitly studied. Here we investigate both feeding and parental care behaviors and molecular regulatory pathways in Astatotilapia burtoni, a cichlid fish that undergoes extended voluntary periods of starvation and wasting while mouth-brooding offspring. We investigate activity levels of neuropeptides implicated in feeding and parental-care regulatory circuits in the cichlid brain through immunohistochemical staining, and track gene expression patterns in select regions of the hypothalamus and pituitary as well as in key peripheral tissues such as the midgut and liver through RNA-seq. We furthermore assess feeding motivation through operant conditioning assays, and plasma levels of key behavior-regulating hormones through ELISAs. The results of our on-going work implicate differential regulation of both appetite and metabolic pathways between brooders and fasted non-brooding subjects, as well as hormonal changes correlating with degree of parental care investment. Each of these levels of investigation both informs and is informed by the output of the other levels, allowing us to pursue a model of appetite and parental care co-regulation of greater depth than would be possible through the independent investigation of these trade-off behaviors at individual systemic levels.

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