Effects of temperature on physiological metabolism and carbon budget of green mussel ( Perna viridis ) and pearl oyster ( Pinctada fucata )

In this study, the rates of ingestion (IR), respiration (RR), ammonia excretion (AR), faecal production (FR), and calcification (CR) of green mussel (Perna viridis) and pearl oyster (Pinctada fucata) were determined across four different temperature levels. Additionally, the carbon budgets of these two bivalves under different temperatures were also modelled. The IR, RR, AR, FR, and CR of both green mussels and pearl oysters were significantly affected by temperature changes. The peak values for these parameters were observed at 26°C, except for the CR of the green mussel and the AR of the pearl oyster. At temperatures ranging from 22°C to 30°C, the IR, RR, AR, and FR of the pearl oyster were significantly higher than those of the green mussel, whereas the opposite trend was observed for the CR. Specifically, negative CR values were recorded in both species at 18°C. The growth carbon (GC) ratio of green mussels initially increased and then decreased as the temperature rose, whereas the GC ratio of pearl oysters remained relatively stable across varying temperatures. The GC ratios of pearl oysters were higher than those of green mussels, while green mussels displayed higher faecal production carbon ratios than pearl oysters.