Subterranean Fishes of the World

5632

2022

AIM 2022

56

Many organisms, especially fish, exhibit alternative reproductive tactics (ARTs), where males of the same species perform different reproductive behaviors. Often larger males will court the female, while smaller males perform a non-courting behavior. Here we investigate whether males with distinctive ARTs in the northern El Abra swordtail, Xiphophorus nigrensis, also have distinctive coping styles. Coping styles are defined as a set of behavioral and physiological responses that are consistent over time in an individual. Proactive animals tend to be bolder and have low basal and post-stress cortisol, whereas reactive animals are more anxious and have high levels of cortisol. Xiphophorus nigrensis have three male phenotypes with alternative reproductive tactics. Two of the male types follow a fixed strategy: larger males will court the female, the smaller males chase and coerce the female during copulation. The intermediate sized males deploy a mixed strategy, they both court and coerce females. Using a test for boldness (scototaxis), we show that males that coerce are bolder than males that court. In future experiments, we will employ a series of behavioral assays to measure boldness and aggression, along with experiments measuring stress response (cortisol levels) in these fish to understand whether coping styles are associated with mating behavior, i.e., whether proactive and reactive styles are associated specifically with courtship and coercion behaviors. This study will thus investigate whether the sexual selection that gives rise to these ARTs also has downstream consequences on non-reproductive behavioral and physiological traits.

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