Date of Award
2024
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Biological Sciences
Committee Chair
Zach Culumber
Committee Member
Matt Niemiller
Committee Member
Bruce Stallsmith
Research Advisor
Zach Culumber
Subject(s)
Eastern mosquitofish--Variation, Eastern mosquitofish--Color, Melanins, Variation (Biology)
Abstract
Genetic variation often precedes adaptation, so the mechanisms that maintain this variation are a central topic in evolutionary biology. Gambusia holbrooki, or eastern mosquitofish, possesses a rare polymorphism for melanistic coloration. Melanics and typical silver males were examined for differences in behavioral and physiological traits that may impact the persistence of the melanism trait. No differences in standard metabolic rate were found via closed-chamber respirometry, but a detour task indicated that melanic males possess greater cognitive flexibility. Effects of the social environment on stress and reproductive traits were also evaluated by pairing males and comparing cortisol levels and sperm quality to individual baselines. These controlled social pairings revealed no significant relationships between social factors, stress, and reproductive traits. Future work may better illustrate the role of environmental factors on the persistence of melanism by thoroughly characterizing both competitive and reproductive interactions and evaluating potential physiological mechanisms underlying differences in cognition.
Recommended Citation
Giltner, Katelyn, "Potential mechanisms maintaining a conspicuous polymorphism in eastern mosquitofish (Gambusia holbrooki)" (2024). Theses. 688.
https://louis.uah.edu/uah-theses/688