Meeting Abstract
106.6 Tuesday, Jan. 7 09:45 Reproductive choices, hormones, and behavior in bluebanded goby (Lythrypnus dalli) social groups SOLOMON-LANE, T.K.*; WILLIAMS, M.M.; MARTINELLI, A.C.; THOMAS, A.; ROGERS, L.; GROBER, M.S.; Georgia State Univ., Atlanta; Agnes Scott College, Atlanta; Colombia Univ., New York; Agnes Scott College, Atlanta; Agnes Scott College, Atlanta; Georgia State Univ., Atlanta tsolomonlane1@student.gsu.edu
Reproductive choices are complex and influenced by internal and external factors including social status, group behavioral dynamics, and steroid hormones. Bluebanded gobies (Lythrypnus dalli) form hierarchies of one dominant male and multiple subordinate females, and reproduction in these groups is related to patterns of agonistic interaction and individual reproductive state/behavior. To examine the causes and consequences of reproductive choices, we formed social groups with females of specific reproductive states: the highest (alpha) and middle-ranking females (beta) were either very gravid or not gravid (gamma was never gravid). Within 48 hours, eggs were laid in 45% of groups with at least one gravid female, and 73% of the layers were alphas, indicating an advantage for social dominance. The presence of multiple gravid females was a strong motivator to reproduce: eggs were laid in 78% of groups with a gravid alpha and beta compared to 42% of groups with only a gravid alpha or 25% of groups with only a gravid beta. Despite these dramatic reproductive differences, behavioral variation among groups was nuanced. Male- and gamma-initiated behaviors, particularly directed at beta, varied among treatments, as did beta agonistic efficiency. In addition, although neither alpha gravidity nor the presence of eggs affected behavior, beta gravidity may be a salient signal. Finally, we examined associations between steroid hormones (systemic, brain) and individual behavior and reproduction. These data provide critical insights into the proximate regulation of reproductive success in social species.
