The biochemical transformation of food by the mussel Mytilus galloprovincialis Lamarck at different temperatures

Abstract

The influence of temperature on the biochemical composition of the faeces of Mytilus galloprovincialis has been examined in the range of temperatures from 10° to 25°C. Percentage content of ash and carbohydrates decreased with an increase in the temperature from 40.2% ± 2.8% to 19.6% ± 1.1% and from 25.9% ± 2.3% to 19.9% ± 1.9%, respectively. The content of lipids and proteins increased with an increase in the temperature from 5.8% ± 0.4% to 14.9% ± 1.9% and from 23.4% ± 4.3% to 46.7% ± 3.3%, respectively. Among neutral lipid classes, the most essential alterations were connected with triacylglycerols, sterol and wax esters (percentage content of these compounds increased from 0.2% ± 0.1% to 7.2% ± 2.0% and from 3.4% ± 0.5% to 9.0% ± 1.2%, respectively) and with hydrocarbons (their content decreased from 63.5% ± 6.9% to 32.2% ± 3.7% with an increase in the temperature). An extremely significant influence of temperature was shown on the percentage content of total phospholipids and polar lipids (their content increased from 0.2% ± 0.5% to 4.2% ± 0.2% and from 7.1% ± 0.9% to 33.6% ± 3.6%). Amino acid composition of proteins that presented in the faeces was rather constant, and only an insignificant increase in the correlation of essential/nonessential acids took place at low temperatures. The fatty acid compositions of investigated lipid classes were different and altered in different ways with an increase in temperature, but the increase in the ratio of w3 w6 acids with increase in the temperature was the characteristic feature of all lipid classes. The most abrupt alterations in the biochemical composition took place in the interval of temperatures from 20° to 15°C. These alterations are connected with high energy substances and point to the process of cold adaptation of M. galloprovincialis as connected with these compounds and in this interval of temperatures.