WIDMER, S.*; MOORE, P.; BAGATTO, B.; University of Akron; University of Akron; University of Akron: The Effects of Chronic Hypoxia on the Aerobic Characteristics of Zebrafish Muscle

The environmental conditions during development can be an important factor affecting the physiology of the adult animal. The purpose of this experiment is to measure the effects of chronic hypoxia on the morphology and physiology of zebrafish aerobic muscle. The control zebrafish were housed in an aquarium system maintaining normal oxygen levels, while the treatment zebrafish were housed hypoxic conditions since the 8-cell stage. Zebrafish housed in chronic hypoxia should have a higher mitochondrial density and therefore be able to aerobically outperform control zebrafish in either environment. Zebrafish were maintained in the two separate environments until reaching the adult stage (approximately 120 days). Muscle cross sections were taken from a subset of the population and stained to show mitochondria. Mitochondrial density was calculated by digitizing the cross sections and using ImagePro software. Aerobic performance was measured in both groups of zebrafish and measured in both environments. At this point, there are no significant differences in the amount of aerobic muscle tissue between zebrafish raised in normoxia versus hypoxia. More importantly there are no significant differences in the ratio of total aerobic muscle area (TAA) to total cross sectional area (CSA) between zebrafish raised in normoxia versus hypoxia. However, it appears that mitochondrial density is higher in the zebrafish raised in hypoxia. This should allow this group of fish to aerobically outperform their normoxic counterparts in at least the hypoxic environment.