Meeting Abstract
25.5 Wednesday, Jan. 5 Elevated sea water temperatures could result in rapid local adaptation of an intertidal predator PRICE, R. M.; University of Washington, Bothell becca.price@uwb.edu
One approach toward elucidating the effects of global climate change is to grow species at elevated temperatures under controlled laboratory conditions. The intertidal, predatory snail Nucella provides an ideal system for such experiments because its growth rates vary considerably under different environmental conditions and because its geographic range spans different bioregions characterized by different temperatures. I examined how growth rates in N. lamellosa change when exposed to temperatures typical of an adjacent but warmer bioregion. N. lamellosa individuals were maintained in separate mesocosms with running seawater and fed barnacles (Balanus glandula) ad libitum for 24 days. 20 individuals were maintained at 13oC in a control treatment, and 10 individuals were maintained at 19oC in an experimental treatment. The change in tissue weight, shell weight, height and the degrees of growth at the shell margin were measured. Preliminary analyses suggest that snails in the elevated temperature treatment grew faster than those in the control treatment. However, snails in the elevated temperature treatment also exhibited more variance. These trends are statistically significant for only some metrics of growth. These preliminary results suggest that individuals vary in the degree of plasticity of growth rates; that is, some individuals grow faster in elevated temperatures, but some grow more slowly. Because other studies have found a genetic basis for heat tolerances in Nucella, these results imply that N. lamellosa could adapt quickly to local increases in seawater temperatures. Individuals who thrive at higher temperature would have a larger body size and therefore higher reproductive fitness, and individuals who grow more slowly may go extinct.
