Megan Gibbons Research Interests:

Advantages of Egg Mass Phenotype

In larval amphibians, anti-predator defense is important from the time of embryonic development until metamorphosis.  During interim and Spring of 2005, Kayla Calton, Melanie Jobe, and Nikki Rombough began investigating the potential advantage of a point mutation in spotted salamanders (Ambystoma maculatum), which changes the phenotype of the egg masses of this species from clear to opaque.  At our study site (Henry Farm Park in Jacksonville, AL), the proportion of clear to opaque egg masses is approximately 1:1.  We have begun to conduct studies to determine if different egg mass morphotypes affect the survivorship of embryos and the anti-predator defense of emerging larvae.  We are testing anti-predator behaviors of larval A. maculatum against 3 predator types: marbled salamander larvae (Ambystoma opacum), crayfish, and mosquitofish (Gambusia affinis).  In 2006, Jacob Lindsey investigated the preference of several egg predators, including caddisfly larvae, red-spotted newts (Notophthalmus viridescens), and bullfrog tadpoles (Rana catesbieana) for clear versus opaque egg masses.  We are still investigating this question, and have not yet determined if there is any advantage to one phenotype over the other.