Group versus Individual Exercise Differentially Affects Stress Hormone Release in Zebrafish (Danio rerio)

Abstract

Zebrafish (Danio rerio) are a small, tropical freshwater fish native to Southeast Asia. They are advantageous to the study of behavior and physiology due to their high physiological and genomic homology to mammals, external fertilization, rapid development, ease of experimental manipulations, and cost‐ and space‐effectiveness. It is well known that exercise is beneficial, but it is becoming increasingly important to understand the psychological and physiological consequences (both positive and negative) to individuals who engage in exercise. The purpose of this experiment was to determine whether cortisol release was affected by group versus individual exercise in zebrafish. Adult, wild‐type male and female zebrafish housed in a community aquarium were exercised in a swim tunnel at a moderate intensity for 10–20 minutes either individually or in small groups (4–5). Control fish were placed in the swim tunnel but it was not turned on. Immediately following each exercise bout, fish were placed in small containers of water to collect cortisol secreted from their gills. Fish that were exercised in a group had lower cortisol levels compared to fish that exercised individually. Fish that were kept in a group, whether exercised or not, secreted less cortisol during the subsequent sampling period. Exercising alone seems to cause the greatest stress response in zebrafish; fish that were exercised individually secreted the greatest amount of cortisol compared to other groups.Support or Funding InformationResearch in this abstract was supported by the National Institute of General Medical Sciences of the National Institutes of Health under award number P20GM103447. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.