Meeting Abstract

47.5  Wednesday, Jan. 5  The effects of social environment on behavioral and morphological development in isogenic strains of the mangrove rivulus (Kryptolebias marmoratus) FULLER, Adam B.*; EARLEY, Ryan L.; University of Alabama, Tuscaloosa; University of Alabama, Tuscaloosa atom.fullerene@gmail.com

Reaction norms describe the phenotypic response of a particular genotype to a range of environmental conditions. However, the study of reaction norms in vertebrates is hampered by a paucity of species that reproduce clonally. We used natural isogenic strains of the self-fertilizing hermaphroditic mangrove rivulus Kryptolebias marmoratus to investigate the effects of social environment on phenotype. The unique reproductive strategy and population structure of the mangrove rivulus allowed us to expose genetically identical fish to different social environments. Fish were raised from embryos to maturity (70d) either in isolation or in groups of 2 to 4 animals. We measured total and standard length three times (at 50, 60, and 70d) and levels of aggression (at 70d). Time to approach and attack a model fish was used to estimate aggression levels. Mangrove rivulus raised in small groups grew significantly faster than genetically identical fish raised in isolation, despite increased competition for food. As expected, there also was significantly greater variance in body size in group-housed compared to isolated animals. We are conducting follow-up experiments to examine how social environment affects feeding rates and aggression in other contexts (mirror image stimulation, interactions with familiar and unfamiliar fish). This talk will present the results of our experiment as well as the utility of K. marmoratus as a model organism for studying the combined effects of genes and environment on vertebrate behavior and physical phenotype.