Little is known about the biogenetics of gastropods. To address this, we measured the standard metabolic rate (SMR) of at different water temperatures, salinities, and time regimes. We measured SMR every 6 h using the bottle-incubation method. Individuals were incubated at six temperatures (from 10 to 35 consumption rate, ammonia excretion rate, and CO₂ emission rate of the two gastropods were significantly affected by water temperature (B. aeruginosa varied significantly with changes in temperature and salinity, causing changes in enzyme activity. We calculated the consumption rate, ammonia excretion rate, and CO₂ emission rate. These indices can be used to indicate energy sources and provide insight into how individuals cope with environmental changes. The ratio of O:N and the respiratory quotient, indicators of protein consumption, were lowest at 25°C suggesting this is the optimal temperature for values suggest that to changes in temperature. Increases in salinity were associated with an increase in metabolism (e.g., O₂ consumption and CO₂ emission) due to the extra energy required for regulation of ionic equilibrium. The reduced sensitivity towards changes in temperature suggests that these gastropods are minimizing energy consumption during changes in temperature, thus preserving energy for ionic homeostasis. The metabolic activity of , was significantly affected by the interaction between temperature and salinity. The metabolic rate of both gastropods fluctuated diurnally, being higher during the night. This likely reflects the diurnal pattern of activity in both species, which tend to feed and compete for dissolved O₂ during the night.