Comparative Maternal Phenotypes in a Mouthbrooding Cichlid

Abstract

Maternal care behavior is plastically adjusted based on external and internal cues. Differences in maternal phenotypes can be observed between laboratory raised animals and their wild-raised conspecifics, eliciting the question of how environmental stimuli processing and internal physiological signals integrate to produce adequate maternal behavior. These inextricably linked networks have often been studied in isolation, but a thorough investigation of maternal phenotypes requires an investigation of the interplay between internal and external sources that affect reproductive mechanisms. Using an integrated comparative approach, this study examines behavioral, physiological, and hormonal contrasts between lab-raised and wild-raised stocks of the brooding cichlid fish Astatotilapia burtoni, which demonstrate divergent patterns of maternal investment. Brooders were placed into treatment groups at various time points throughout the brooding cycle and behavioral, morphological, and hormonal data was collected and compared between stocks and brooding stages. Results indicate significant differences in rates of filial cannibalism and weight regulation between the two stocks, revealing a phenotype contrast between good and inept brooders. These findings contribute to the limited compendium on the neural mechanisms which influence maternal care behaviors.