Meeting Abstract

P2-162    Three rivers diverged in the woods, and so did the guppies Crawford, CH*; Smith, K; Evans, KM; Kane, EA; University of Louisiana at Lafayette; Georgia Southern University; Rice University; University of Louisiana at Lafayette crawford.callie@gmail.com

The necessity of coordinated function in morphological traits can lead to morphological integration, or correlated variance among morphological traits. However, different selection pressures due to varying environmental conditions can impact traits and influence their function and integration. Species with populations experiencing divergent environments, such as Trinidadian guppies (Poecilia reticulata ) are ideal for studying how ecological pressures influence morphological trait integration. In P. reticulata, numerous traits vary due to ecological divergence between high and low predation populations, including shape and morphological traits, but studies mainly focus on males and have not assessed the role of morphological integration in these changes. Recent work has shown that kinematic integration evolves in low-predation populations but is absent in the high-predation ancestral populations. Therefore, since morphology is predictive of performance, we ask whether integration of morphological traits follows a similar pattern. We use geometric morphometrics of 2D landmarks on external morphology to quantify shape and morphological integration in female Trinidadian guppies from three drainage systems, incorporating populations with high and low predation pressures. We do not find differences in morphology or integration between divergent populations; however, we do see differences between drainage systems. These differences lead us to consider constraints on female body shape and how earlier separation of the drainage systems has supported morphological divergence while more recent population separation has not.