The Effect of Male-Typical Hormone Injections in the Fin Morphology of Lythrypnus dalli
Faculty Mentor Information
Makenzie Reed, Idaho State University; and Dr. Devaleena Pradhan, Idaho State University
Presentation Date
7-16-2026
Abstract
Fish fins play critical roles in swimming and parental care. The bluebanded goby, Lythrupnus dalli, is a socially haremic fish where the male utilizes endocrinological signaling and complex fin movement to perform parental care. We aimed to investigate the endocrinological and morphological influence of the dorsal and caudal fins on parental behaviors. Pairs of one male and female were placed in a tank and screened for parental care behaviors three days later. If the male parented, the group was recorded for one hour to establish parenting baselines. Both fish were then removed from the tank, and the male was injected at the caudal muscle with one of four treatments (phosphate buffer, carbenoxolone, carbenoxolone + 11-keto-testosterone, or cortisol). Male parental care was recorded one hour immediately after injection and 24 hours post-injection. Following the final recording, fish were euthanized and photographed for morphological analysis. Using ImageJ, caudal and dorsal morphological features were measured including fin area, length of longest point, and width. No difference in any morphological measures was found between the two time points across all treatments. These fin measurements will provide fin morphology insights for future studies including high-speed recording analysis.
The Effect of Male-Typical Hormone Injections in the Fin Morphology of Lythrypnus dalli
Fish fins play critical roles in swimming and parental care. The bluebanded goby, Lythrupnus dalli, is a socially haremic fish where the male utilizes endocrinological signaling and complex fin movement to perform parental care. We aimed to investigate the endocrinological and morphological influence of the dorsal and caudal fins on parental behaviors. Pairs of one male and female were placed in a tank and screened for parental care behaviors three days later. If the male parented, the group was recorded for one hour to establish parenting baselines. Both fish were then removed from the tank, and the male was injected at the caudal muscle with one of four treatments (phosphate buffer, carbenoxolone, carbenoxolone + 11-keto-testosterone, or cortisol). Male parental care was recorded one hour immediately after injection and 24 hours post-injection. Following the final recording, fish were euthanized and photographed for morphological analysis. Using ImageJ, caudal and dorsal morphological features were measured including fin area, length of longest point, and width. No difference in any morphological measures was found between the two time points across all treatments. These fin measurements will provide fin morphology insights for future studies including high-speed recording analysis.