BARNARD, E.; BAGATTO, B.; University of Akron; University of Akron: Effects of Maternal Diet on Reproductive Strategies and Embryo Development in the Zebrafish, Danio rerio

Organisms are constantly challenged with changes in the environment. To survive and pass on their traits, they must be capable of adapting to the changes that take place in that environment. To understand how environmental change, such as food quality, affects developing embryos through maternal avenues, we subjected female zebrafish (Danio rerio) to different diets. The zebrafish were divided into three groups: a high-fat diet group, a moderate-fat group, and a fasting group. After the groups had acclimated, we bred them over a 2-week period and measured likelihood of mating, fecundity, and egg size. Various characteristics of the developing embryos were also measured through to hatching. Females in the high-fat diet group were more likely to mate and produced far more offspring than either the moderate or fasting group. However, a higher percentage of the eggs in high-fat diet group did not develop beyond 24 hours. The size of the eggs laid by the fasting group was significantly larger than those of the other groups. In addition, the eggs laid by the fasting group had larger reservoirs of yolk. This may reflect two reproductive strategies. When food is abundant, the fish may attempt to take maximum advantage from the situation by producing as many offspring as possible, thus assuring that their progeny take up a larger percentage of the expanding population. In contrast, when food is scarce, the zebrafish may put their effort into producing fewer eggs that are more likely to survive in an environment where competition for food is high.