The Effects of Cortisol on Cardiac Development/Functionality in Zebrafish

Cortisol affects development, not only in zebrafish, but mammals as well. Experiments have concluded that cortisol can affect zebrafish cardiac development, but these experiments injected the embryo itself with the cortisol. The aim of my experiment is to examine the effect of cortisol on cardiac development by adding cortisol into the water, much like the way zebrafish embryos would encounter maternal cortisol in their natural environment (Pikulkaew et al., 2011). Based off of the results of previous experiments, I predict that cortisol levels in the water will affect the cardiac development of zebrafish. In my experiments, I utilize the fast breeding and growing characteristics of zebrafish to collect clutches of eggs. I separated the clutches into two groups: cortisol-treated and a group without treatment (water) . The group without the hormone serves as a control group to determine the number of embryos in a selection that develop improperly, without the treatments. The cortisol-treated tank serves as the experimental group. Zebrafish were acquired, maintained, and their breeding behaviors as well as developmental stages were determined before experimentation. Clutches of eggs were treated and documented over the course of three days. After analysis through Chi square testing, cortisol appears to affect the cardiac functionality and development in some of the fish exposed.