Thermal tolerance and preference of exploited turbinid snails near their range limit in a global warming hotspot.
The thermoregulatory behavior of sea hare Aplysia californica was determined in a horizontal thermal gradient; with a preferred temperature (PT) of 18.3 ̊C for the day cycle and 20.8 ̊C for the night cycle. The displacement velocity demonstrated an initial rate of 30 cm·h and gradually the velocity diminished to 18 cm·h with several fluctuations mainly at 02:00 am. Critical Temperature Maxima (CTMax refers to the temperature point where at least 50% of the experimental group have a loss of attachment) was measured at three acclimation temperatures (16 ̊C, 19 ̊C and 22 ̊C). At the lowest acclimation temperature (16 ̊C), 50% of the experimental group had an attachment loss at CTMax 32.7 ̊C, and in a higher acclimation temperature (22 ̊C) CTMax was 36.2 ̊C. The Oxygen Consumption Rate (OCR) was closely correlated to acclimation temperature, and at 16 ̊C and 19 ̊C sea hare had a relatively stable metabolic rate, with OCR increasing to 9 mg O2 h·kg w.w. in a higher acclimation temperature.