Hatch Plasticity in Sheepshead Minnow Embryos in Response to Predator Presence

Hatch plasticity, the ability of embryos to alter hatch timing to minimize stage-specific risks, is investigated for the first time in the sheepshead minnow Cyprinodon variegatus, an ecotoxicological model organism.  In this study, we reared C. variegatus embryos in the presence of a predation stimulus, the mummichog Fundulus heteroclitus.  We measured mean hatch timing of C. variegatus eggs reared with two treatments of F. heteroclitus: those fed an innocuous diet of commercial flake food and those fed the same diet supplemented by C. variegatus eggs.  Preliminary data suggest that eggs raised in the presence of this predator do not significantly alter hatch timing.  We discuss both reasons for the lack of observed hatch plasticity in this experiment and the need for ecological studies of ecotoxicological model organisms.