Meeting Abstract
We explored the response of two physiological parameters, metabolic rate (VO2) and heart rate (HR), in two species of pulmonate snails in response to acute and chronic temperature elevations. Land snails, Asian tramp snail (Bradybaena similaris, BS) and Milk snail (Otala lactea, OL) were collected from central Texas and acclimated to laboratory conditions. Snails were chronically exposed to either low (22°C) or high (30°C) ambient temperatures for a minimum of two weeks. Following the two week acclimation, VO 2 and HR were measured in both B. similaris and O. lactea in the low temperature (22°C; BS-22 and OL-22) and elevated temperature (30°C; BS-30 and OL-30). We measured HR and VO2 in response to acute exposure to the acclimated and reciprocal temperatures. We predicted that snails exposed to acute and chronic elevated temperature would display depression of metabolic rate and heart rate. We observed metabolic depression in BS-22 when measured at 30°C, while HR increased 26%. HR in BS-30 increased 24% when measured in 30°C compared to measurements collected at 22°C. VO2 of OL-30 measured at 30°C was 24% lower than OL-22 measured at 22°C. HR of OL-22 and OL-30 was unaffected by acute temperature changes, however there was a reduction in HR in OL-30 measured at both temperatures compared to OL-22. In our study we found that the pulmonate snails collected from central Texas did not respond to changes in environmental temperature in the similar manner. While we did confirm the impact of temperature on VO2, in both acute and chronic exposures, HR responses were variable in response to acute and chronic changes in temperature, with B. similaris responding to acute changes in temperature, while O. lactea responses were primarily due to prolonged exposure.
