Search

Previous feeding studies on herbivorous marine snails rarely have focused on temperature effects on food intake. If temperature affects food intake, ectothermic snails may experience difficulty obtaining sufficient nutritional resources, limiting their ability to sustain populations at suboptimal temperatures. We hypothesized that the feeding responses ofTegulaspecies would correspond with temperatures characteristic of their geographic distributions. We determined activity, consumption rates, and gut passage times at 11°C, 15°C, 19°C, and 23°C for threeTegulaspecies with distinct thermal distributions:T.brunnea(cold water),T.aureotincta(warm water), and individuals from warm- and cold-water populations ofT.funebralis, a broadly distributed species. Activity and consumption rates ofT.aureotinctaincreased with increasing temperature, but were highest forT.brunneaat 19°C, a temperature rarely achieved in habitats occupied by this species, and lowest at 11°C. Warm-waterT.funebralisshowed significantly lower activity and consumption rates at 11°C, whereas cold-waterT.funebralisconsumed food fastest at 15°C and were most active at 23°C. Temperature affected gut passage time only inT.aureotincta. These data suggest that temperature might influence the northern limit ofT.aureotinctaby affecting activity and food consumption rates.T.brunnea’s activity and ability to consume food were not hindered by warmer temperatures despite the present day restriction of this species to colder waters. Also, widely separated (>300 km)T.funebralispopulations may be adapted to regional conditions based on the different temperature responses of northern and southern snails. [ABSTRACT FROM AUTHOR]