Meeting Abstract
P2.125 Friday, Jan. 4 Breeding density effects on plasma and yolk hormones in green anole lizards: a laboratory study ADAMS, A.L.*; LIGON, D.B.; LOVERN, M.B.; Oklahoma State University; Oklahoma State University; Oklahoma State University amber.l.adams@okstate.edu
A diversity of studies has demonstrated the potential for females of oviparous species to alter their yolk hormone deposition based on salient aspects of their social environment. Furthermore, females as well as males may experience socially-mediated changes in plasma hormone concentrations. In the present study, we housed breeding female green anoles in cages with either one male or one male and three additional females to evaluate the effects of breeding density on plasma and egg yolk testosterone (T) and corticosterone (B). Breeding males and females were randomly assigned to either a low or high density breeding group. Snout-to-vent length (SVL) and mass were recorded for each individual. All animals were maintained under standard breeding conditions for ten weeks and nest boxes were checked daily for eggs. For each egg, we recorded mass to the nearest mg, after which we froze it at -20C. At the end of ten weeks, SVL and mass were recorded again and we collected blood samples from each individual. Over the course of breeding, body condition significantly declined for males and females irrespective of treatment group. Treatment also had no effect on egg mass, although there was a trend towards increased egg output for females in low density as compared to high density breeding groups. Plasma and yolk T and B levels will be analyzed by radioimmunoassay to determine how males and females responded hormonally to breeding density and to what extent females in the two treatment groups differentially allocated T and B to their eggs. If such differential allocation is shown, then social environment effects on reproductive effort potentially may include changes in egg output as well as more subtle changes in steroid allocation to those eggs.
