Published online by Cambridge University Press: 16 December 2014
Blue mussels (Mytilus edulis) and soft-shell clams (Myaarenaria) are both aquaculture species in east coast of Canada and US shellfishfarmers take advantage of the byssal threads production of mussels for suspension cultureand the burrowing behaviour of soft-shell clams for enhancement practices. It is importantthat these animals attach and burrow efficiently to minimize losses during rearing. Theaim of this work was to study two potential vitality indices on mussels (23.6 ± 0.1 mm) and clams (22.6 ± 0.1 mm) seeds following variousperiods of emersion: attachment strength of Mytilus edulis and burrowingability of Mya arenaria. The effect of emersion on energy content(proteins, lipids, glycogen) was also examined. We observed no significant decrease in theattachment strength of mussels after air exposure for 78 h or in the burrowing efficiencyof soft-shell clams after 54 h. Air exposure had no effect on different lipid classes,proteins, or glycogen content in either mussel or clam tissues. The stressful emersionevent induced in our study may not have been high enough to induce detectable behaviouralresponses. This can be explained by the bivalves’ ability to adapt their metabolism tominimize activity during air exposure. In doing so, they do not consume their energyreserves, which are then still available when specimens are reimmersed. Thus mussels areable to efficiently produce byssal threads and clams to burrow into sediments as soon asthey are back in the water.