Physiological responses of the Asian green mussel (<i>Perna viridis</i>) in highly turbid waters

In order to simulate conditions induced by climate change, the filtration rates and pseudofaeces production of Perna viridis from two distinct size categories were investigated at progressively increasing total suspended solid concentrations. Filtration rates of smaller mussels increased with increasing total suspended solid concentration. For larger mussels, filtration rates increased with increased concentration up to 800 mg L–1, after which filtration rate dropped sharply. Pseudofaeces production also increased with increasing total suspended solid concentration up to 600 mg L–1, beyond which no further significant increase was observed for large mussels, and there was a considerable decline for small mussels. The results show that the mussels of different sizes have different filtration rates with smaller mussels ranging from 0.11 to 2.62 mg min–1 and in larger mussels from 0.21 to 4.83 mg min–1. Pseudofaeces production ranged from 0.08 to 0.67 mg min–1 for small mussels and from 0.02 to 1.42 mg min–1 for larger mussels. These results may imply that smaller mussels are more vulnerable to siltation and high sediment load compared to larger individuals. In the natural environment, this situation can be caused by more frequent and severe typhoons resulting from climate change.