Adjustment of the activity of α-amylase extracted from the style of the black mussel Choromytilus meridionalis (Krauss) in response to thermal acclimation

The mussel Choromytilus meridionalis (Krauss) is a common inhabitant of the intertidal zone on the west coast of the Cape Peninsula, South Africa, and experiences temperatures of between 8°C when immersed by the tide and at least 25°C on exposure to air. The activity of α-amylase extracted from the crystalline style of freshly-collected mussels has a low temperature coefficient of ≈ 1.12 over much of the temperature range experienced in the natural environment. Warm acclimation results in an increase in the α-amylase activity, despite the fact that individual rate: temperature curves for extracts from mussels acclimated to 8, 15 and 22°C have rather low temperature coefficients of 1.14–1.17 between 10 and 20°C. The increase of activity of the α-amylase following warm acclimation may form an integral part of the improved filtration, ingestion and assimilation which is necessary to offset increased metabolic losses during the warm conditions of the summer months.