Shaina Villalobos

Shaina Villalobos, University of Maryland, College Park

Shaina collecting minnow eggs

Project: Maternal Effects and Transgenerational Plasticity in Cyprinodon variegatus in Response to Temperature

Advisor: Steve Munch

Understanding how organisms will react to climate change, and being able to make predictions about their ecology, is of extreme importance to the field. When discussing thermal physiology and adaptation, it was previously believed to be slow to evolve, and relatively static. Thermal transgenerational plasticity is an epigenetic effect that affects the offspring of thermally stressed parents.  Transgenerational plasticity may allow much quicker adaptation to thermal stress in a wide array of species.  The goal of this experiment was to further investigate thermal transgenerational plasticity in Cyprinodon variegatus, the sheepshead minnow. Sheepshead minnows are the first documented vertebrates hypothesized to exhibit thermal transgenerational plasticity.  While thermal effects on egg size in fishes are well known, it is unclear how long it takes for these effects to manifest and how long they persist.  To address this, I measured the numbers, sizes, and viability of eggs produced by sheepshead minnows (Cyprinodon variegatus) growing at 24, 28, and 32 oC.  Egg counts and sizes were obtained from photographs of eggs collected biweekly for a month.  One egg collection each week was transferred to larval rearing chambers at 28 oC to measure viability.  In keeping with previous studies, I found that parents at low temperature produced larger eggs than parents at high temperature.  Importantly, differences in egg size were apparent within the first week of collections and increased to 14% by the end of the month study period.

Shaina measuring egg size