LIPID CLASS AND GLYCOGEN-CONTENT OF THE LUGWORM ABARENICOLA-PACIFICA IN RELATION TO AGE, GROWTH-RATE AND REPRODUCTIVE CONDITION

We measured the levels of lipid classes (wax esters, triacylglycerides , free fatty acids, sterols, phospholipids) and levels of glycogen in a population of AbaP enicoin pacifica over a one-year period beginning shortly after recruitment. Glycogen and lipid contents were unrelated to growth rates as estimated by changes in average size of individual s in the cohort. There was no indication of seasonality in levels of a ny component, consistent with the hypothesis of Slobodkin and Richman that animals living in environments where food supplies are likely to be stable, such as subsurface deposit-feeders like A. pacifica, do not accumulate energy reserves. Instead, glycogen content increased gradu ally and most lipid classes decreased gradually over time. A notable e xception was the triacylglyceride content, which showed a large increa se associated with the formation of eggs. Triacylglyceride levels in o lder A. pacifica and in two other species of deposit-feeding polychaet es showed similar trends. Measurement of triacylglyceride levels may p rovide an additional objective method, supplementing egg counts and eg g size, of quantifying reproductive effort in deposit-feeders.