Seasonal variations of the major lipid classes in relation to the reproductive activity of two species of clams raised in a common habitat: Tapes decussatus L. (Jeffreys, 1863) and T. philippinarum (Adams & Reeve, 1850)

Abstract

The relative and absolute levels of four major lipid classes in an indigenous and an introduced adult clam population raised in a common habitat were determined over a 74-wk period. The standard animal of each population contained a low and stable amount of the fraction containing wax esters, hydrocarbons, and sterol esters. The absolute levels of triacylglycerols and phospholipids closely followed the indices of reproductive activity. Following the summer spawning a severe negative energy balance was observed throughout the winter. During this period, both triacylglycerols and phospholipid contributed to the maintenance energy, although the phospholipids' contribution was greater in both populations. A comparison of the seasonal variations of absolute and relative values underscores the advantages of absolute values in the calculation of lipid class levels. Although some specific differences were found in mean lipid class levels, the overall seasonal variations of the lipid classes were similar in both populations.