Parental social environment has transgenerational effects on zebrafish (Danio rerio) growth

Social and physical environment can largely influence behavioral phenotypes in fish. Additionally, developmental environment may not only influence the behavior of an individual, but also that of its offspring. The objective of this study was to investigate the effects of parental social experience (social housing or chronic isolation) on offspring feeding behavior, growth performance, and intestinal health when fed fishmeal-based or soybean meal-based diets. Offspring from zebrafish raised in chronic isolation (CIO) and offspring from zebrafish raised in social housing (SHO) were randomly assigned to 3.0 L tanks with 25 fish per tank. Each tank was randomly selected to be fed either a fishmeal-based (FM) or soybean meal-based (SBM) diet. There were three replicate tanks (n = 3) for each of the four treatment groups (SHOF, SHOS, CIOF, CIOS) with a total of 12 tanks. At the end of the experiment, the offspring of the chronically isolated parents had grown significantly more than the offspring of the socially housed parents regardless of diet type. However, the SHO fish consumed more as a percent of tank biomass during the feed intake tests when compared to the CIO fish of the same diet type. Fish fed with a SBM-based diet had higher numerical expression of inflammation-related genes in the gut in both offspring origin groups suggesting some inflammatory response to the diet. Overall, it appears that parental social experience had an influence on the growth performance of offspring, but the mechanisms remain unclear.