Meeting Abstract

41.8  Thursday, Jan. 5  Going to great lengths: population and genotypic effects on growth and development in the mangrove rivulus STANLEY, S.G.*; GARCIA, M.J.; VAUGHN, S; TAYLOR, D.S.; EARLEY, R.L.; Univ. of Alabama, Tuscaloosa; Univ. of Alabama, Tuscaloosa; Univ. of Alabama, Tuscaloosa; Brevard County Environmentally Endangered Lands Program, Melbourne, Florida; Univ. of Alabama, Tuscaloosa sgstanley@crimson.ua.edu

The mangrove rivulus (Kryptolebias marmoratus) is a powerful model organism in which to evaluate differences in growth rates and morphology among genotypes during ontogeny. Populations of this self-fertilizing hermaphroditic vertebrate are genetically diverse with a mixture of heterozygous and homozygous genotypes. We raised F2 generation offspring derived from 33 homozygous wild-caught fish from seven Florida populations. Every 14 days, subsequent to hatching and preceding maturity (e.g. time to first egg lay), we measured total length (mm), standard length (mm), depth (mm, circumference/girth of individual), and mass (g) allowing for an ontogenetic survey of specific growth rates from lineages throughout rivulus habitats in the Florida mangrove ecosystem. Additionally, morphometric analysis software was utilized to quantify ""form"". We employed Procrustes-based geometric morphometrics (e.g. centroid morphometrics) to elucidate developmental changes in ""form"", uncover patterns of covariation between geographical origin and various measures of size and shape, and decode the genetic contribution to morphological variation. Preliminary data provides evidence for population-level diversification in the ontogenetic trajectories for growth and form.