Seasonal trends in serum lysozyme activity and total protein concentration in dab (Limanda limandaL.) sampled from Lyme Bay, U.K.

Dab serum lysozyme activity was optimal at pH 6·0. While total serum protein concentrations remained unaltered, lysozyme activity decreased significantly following storage of serum at −26° C for between 3–21 days. Transport stress also resulted in significantly decreased serum lysozyme activity, while total serum protein was unaffected. In dab sampled at monthly intervals from Lyme Bay, U.K., during November 1992–October 1993, serum lysozyme activity was minimal in fish sampled during the February–March spawning (low temperature) period, and maximal during the September–October (high temperature) period. There was also evidence of a complementary seasonal variation in the serum total protein concentrations.