Meeting Abstract
In many taxa, embryos adjust the timing of hatching in response to intrinsic and extrinsic environmental cues. Here we investigated the effect of parental and mechanical cues on the timing of hatching and hatchling morphology in the neon goby Elacatinus colini. We established a breeding population of E. colini in the lab, and observed the timing of embryo hatching under parental and artificial incubation conditions. Artificially incubated clutches were divided into two treatments: i) mechanically induced clutches that were shaken every 8 hrs to determine the earliest onset of hatching competence, and ii) non-induced clutches that were allowed to hatch undisturbed. Larvae from each treatment were photographed and preserved for morphological analysis. When incubated with parents, male E. colini were found to induce hatching by actively removing embryos with their mouth and spitting the hatched larvae into the water column. Mechanically induced clutches hatched approximately 20% earlier (134 hours-post-fertilization, HPF), had a smaller propulsive area, and larger yolk sac area than parentally induced clutches (169 HPF). Our results suggest that E. colini embryos are capable of hatching early in response to environmental cues, and provide the first evidence of paternally induced hatching in a coral reef fish.
