Meeting Abstract

P1.64  Thursday, Jan. 3  Feeling the heat: the feeding behavior and growth of Nucella ostrina in response to temperature YAMANE, L.A.**; GILMAN, S.E.; University of South Carolina; The Claremont Colleges lauren.yamane@msci.sc.edu

In the physically harsh environment of the rocky intertidal zone, it is common for organisms to experience a wide range in body temperatures, even over the course of a single tidal cycle. Along the Washington coast,the snail Nucella ostrina (a dogwhelk) has been shown to reach over 30°C during summer afternoon low tides following submersion in 10°C water. These temperatures are known to elicit variable physiological responses, but what do they mean for organism fitness and how are they then translated to the ecosystem at large? To answer these questions, we examined the response of the predatory dogwhelk Nucella ostrina to three emersion temperatures (12°, 20°, and 28°C) and two immersion temperatures (10° and 14°C) during a 20-day experiment at the Friday Harbor Laboratories. Snails were assigned to one of 24 tanks, where all experienced continuously circulating seawater on a simulated tidal cycle. Emersion body temperatures were generated using heat lamps positioned at different heights above the animals, and submersion temperatures were controlled via water heaters. Measurements were made of N. ostrina growth and of the consumed prey, Balanus glandula. The results showed that dogwhelks at 12° and 20°C produced significantly more new shell and overall body mass than those at 28°C. Additionally, snails almost completely ceased feeding at the highest immersion temperature (28°C). Submersion temperatures had the opposite effect on N. ostrina, with increasing growth and predation rates associated with the warmer temperature treatment. Future studies may tease apart the relative importance of exposure to consistently high temperatures compared with high temperature variability for species fitness and interactions.