anomala were isolated and divided into two subsamples. In each season one subsample was used for determining the water and ash contents, while the other one was kept frozen at –80°C in a liquid nitrogen GSI-IX concentration freezer for about one month for the biochemical analysis. The number, weight and length of the specimens used in the different seasons are given in Table 1. The second subsample was subdivided into four subsamples to determine the different biochemical components. The content of the worms’ guts were studied but they was not allowed to empty their guts before the biochemical analysis. The water content was determined by drying a known weight of worms at 50–60°C for 24 h to constant weight,

and the ash content was estimated by burning the sample at 500°C in a muffle furnace for six hours. Total protein was measured calorimetrically using the biuret reaction (Gornall et al. 1949). Lipids were extracted with a polar solvent mixture consisting of chloroform, methanol and water (1:2:0.8), and the fat content was determined by weighing the lipids after solvent evaporation selleck chemical according to Bligh & Dyer (1959). Carbohydrates were estimated according to the method described by James (1995), using the following equation: carbohydrates%=100−(moisture%+protein%+lipid%+ash%). Fatty acids

were determined by dissolving lipid samples in a methanol solution of potassium hydroxide (1M) for complete conversion to FAME (fatty acid methyl esters).

This mixture was then evaporated to dryness and dissolved in methanol before injection into the HPLC. The injected solution was regulated according to the optimal concentration on the calibration curve of each Urease FAME standard. The HPLC (Agilent-1200) separation of fatty acids was done using C18 reversed-phase columns (25 cm) and a UV detector at a flow rate of 1 ml min−1 at room temperature of a 97:3 methanol:water eluent mixture. Amino acids were determined using Dionex (ICS-3000). The seasonal water contents in P. anomala were very similar, fluctuating between 83.65% (of wet weight) in winter and 84.8% in autumn. As shown in Figure 1, the ash content was approximately similar during all seasons (18.7%–18.9%), while total protein took the lowest value (56.2%) in autumn and the highest one (66.5%) in summer. Total lipids fluctuated between 6% in autumn and 10.7% in winter and carbohydrates between 6.5% in summer and 18.7% in autumn. The seasonal changes in fatty acids and amino acids are given in Tables 2 and 3. Polyunsaturated fatty acids (PUFA) were represented mainly by C20:5n-3, which attained the maximum percentage (76.8%) in winter and the minimum (49.6%) in summer. The fatty acid composition was mostly unsaturated (UFA), with the lowest value (49.6%) in summer and the highest (81%) in autumn. Meanwhile, saturated fatty acids (SFA) made up 2.2% in summer and reached a maximum of 38.6% in spring.