THE CARDIAC PERFORMANCE OF BABYLONIA AREOLATA UNDER HEAT STRESS BASED ON PHOTOPLETHYSMOGRAPHY

To explore the feasibility of using photoelectric signals to measure heart rate for evaluating stress resistance in the ivory shell (Babylonia areolata), we utilized a non-invasive photoplethysmography (PPG) method. This study aimed to analyze the cardiac performance curve, investigate the impact of different factors on cardiac performance under heat stress, and conduct accuracy and application in two populations of B. areolata. Our findings revealed that the cardiac signal of the ivory snail contained of both ventricle and auricular components. With increasing temperature, the heart rate showed a tendency to increase and then decrease sharply, following a pattern consistent with the Arrhenius equation. Consequently, the Arrhenius Breakpoint Temperature (ABT) was determined as an indicator of high-temperature resistance. Further investigation indicated that ABT remained unaffected by sex, size, and short-term starvation, but was influenced by domestication temperature and extreme starvation (P<0.05), emphasizing its stability. Importantly, a significant positive correlation was found between individual ABT values and survival time under heat stress (r=0.8479, P=0.003), indicating its accuracy in assessing heat tolerance. The ABT for the Thailand population was (36.55±0.81)℃, significantly higher than that that of the Hainan population (35.42±0.57)℃, P<0.05, which is consistent with findings from the summer growth performance survey. In conclusion, ABT serves as a non-destructive and reliable individual measurement tool for evaluating heat tolerance in B. areolata. This study provides an accurate method for investigating heat stress response mechanisms and offers technical support for genetically enhancing heat resistance traits in B. areolata.