Topshell Tectus pyramis is a coral reef snail of economic and ecological value. This study assessed temperature and salinity tolerance in T. pyramis and the interaction between temperature and salinity on metabolism. The adaptability of T. pyramis was assessed with mortality, respiration, and nitrogen excretion. This study found that snail (T. pyramis) with body sizes of width 60.30 ± 3.46, 40.12 ± 2.34, and 20.02 ± 1.15 mm tolerated temperatures of 15–35, 15–35, and 20–30°C and salinity of 13–38, 18–38, and 23–33‰, respectively. It demonstrates that larger snails can adapt better to variations in temperature and salinity. Temperature and salinity have a significant effect on the metabolism of snails. Smaller snails have a higher metabolism and are more sensitive to changes in temperature and salinity. Overall, results suggest that seawater with 30°C temperature and 33‰ salinity was suitable for T. pyramis.