Meeting Abstract
95.7 Monday, Jan. 6 15:00 The effects of social subordination on female reproductive success in the sex-role reversed Gulf pipefish (Syngnathus scovelli) WALLACE, J.A.S.*; DEATON HAYNES, R.; FRAKER, T.; SCOBELL, S.K.; St. Edward’s University; St. Edward’s University; St. Edward’s University; Brooklyn College jwallac7@stedwards.edu
Intrasexual aggression is a natural stressor in the animal kingdom that often results in social subordination of the losing individual. Previous research on subordination has focused mainly on conventional mating systems where males compete for females. In this study, we examined social subordination in a sex role reversed species where females compete and males are choosy. In syngnathid fishes (seahorses, pipefish, and seadragons), females transfer eggs to the male, inducing male pregnancy. Studies in female pipefish have shown that smaller competitors shift their energetic effort from reproduction to growth and reduce investment in ornamentation. We tested the effects of intrasexual competition on growth and fecundity in female Gulf pipefish (Syngnathus scovelli), a highly polyandrous, sex-role reversed species. Size-matched females were each designated a male and allowed to mate to obtain their baseline fecundity. Pregnant males were removed, and the females competed for 10 days. During this time, social behavior was scored for 15 minutes on four days; a female was designated as dominant if she was displaying the temporary ornament on the last day of observation. Then, females were given a second mate to test for post-competition fecundity. Preliminary data showed that intrasexual competition affected growth and fecundity. Dominant females mated post-competition whereas subordinates did not. Dominant females also had larger ovaries than subordinates. However, subordinate females grew more in total length than dominant females. This study suggests that social subordination can negatively affect fitness in sex role reversed species, and subordinate females display a trade-off between investment in reproduction and growth.
