Big Fin Energy: Comparing Caudal Fin Morphology and Body Size in Lythrypnus dalli
Faculty Mentor Information
Dr. Devaleena Pradhan, Idaho State University; and Makenzie Reed, Idaho State University
Presentation Date
7-16-2026
Abstract
Movement and parental care are behaviors that are essential to many species. In fishes, the caudal fin is essential in supporting both movement and reproductive behaviors. The bluebanded goby, Lythrypnus dalli, is a marine fish that organizes into a social hierarchy composed of one dominant male and multiple females. In these fish, the male cares for the eggs laid by the females. The caudal fin of the bluebanded goby plays a critical role in the parental care behaviors of fanning and rubbing embryos. While the caudal fin is important in performing these behaviors, little is understood on the caudal fin length, width, and area in relation to parental care and general movement behavior. Using ImageJ, photos of the caudal fin of different standard length fish will be used to measure fin size. We hypothesize that caudal fin size will be different based on the behaviors they use their fin for. Specifically, because bigger fish are usually male and perform parental care, they will have larger caudal fins. Understanding the relationship between morphology and behavior reveals the complex nature of how organisms obtain and maintain roles in social hierarchies.
Big Fin Energy: Comparing Caudal Fin Morphology and Body Size in Lythrypnus dalli
Movement and parental care are behaviors that are essential to many species. In fishes, the caudal fin is essential in supporting both movement and reproductive behaviors. The bluebanded goby, Lythrypnus dalli, is a marine fish that organizes into a social hierarchy composed of one dominant male and multiple females. In these fish, the male cares for the eggs laid by the females. The caudal fin of the bluebanded goby plays a critical role in the parental care behaviors of fanning and rubbing embryos. While the caudal fin is important in performing these behaviors, little is understood on the caudal fin length, width, and area in relation to parental care and general movement behavior. Using ImageJ, photos of the caudal fin of different standard length fish will be used to measure fin size. We hypothesize that caudal fin size will be different based on the behaviors they use their fin for. Specifically, because bigger fish are usually male and perform parental care, they will have larger caudal fins. Understanding the relationship between morphology and behavior reveals the complex nature of how organisms obtain and maintain roles in social hierarchies.