49.4 Saturday, Jan. 5 Playing the margins: the fitness consequences of individual behavioral variation in the bluebanded goby (Lythrypnus dalli) SOLOMON-LANE, TK*; PRADHAN, DS; WILLIS, MC; CRUTCHER, JB; GROBER, MS; Georgia State Univ., Atlanta; Georgia State Univ., Atlanta; Georgia State Univ., Atlanta; Rhodes College, Memphis; Georgia State Univ., Atlanta firstname.lastname@example.org
Social hierarchies affect individuals at multiple biological levels. Although behavioral differences among statuses are central to dominance, within-status individual behavioral variation persists in many social species and has reproductive consequences. In the bluebanded goby (Lythrypnus dalli), a highly social, sex-changing fish, the influence of social behavior on the reproduction of group members is status-specific. Individual variation in female behaviors influence the quantity of eggs laid in the social group; male behavior affects hatching success. Aggression by the highest-ranking female (alpha) has the most dramatic effect, reducing the number of egg clutches and total quantity of eggs laid in a social group. The mechanisms underlying the negative effect of aggression on reproduction remain unclear, however, because we were previously unable to measure individual fitness. Here, we developed a simple method of quantifying female fitness using injections (ip) of food dye that persisted in the yoke throughout egg development. Using this method, we tested the effect of social behavior on alpha female fitness and social group reproductive patterns. Specifically, we hypothesize that alpha female aggression affects clutch laying decisions, an influence that may be unique to alpha status. We tested this hypothesis by quantifying social behavior, egg laying, and hatching success in stable social groups over 4 weeks. Elucidating how social behavior influences fitness is critical to understanding the evolution of sociality and the trade-offs between social structure maintenance and individual self-interest.