Humoral immune parameters of cultured Atlantic halibut (Hippoglossus hippoglossus L.)

Several humoral immune factors were studied in a group of cultured halibut (Hippoglossus hippoglossus L.). The serum protein and IgM concentration was comparable to levels seen in other teleost species. A strong antibody acti vity against TNP-BSA was observed but not against other antigens tested. Ly sozyme and anti-protease activity was detected and showed variable heat sen sitivity. Unlike the anti-protease activity, the lysozyme activity of the s era was not sensitive to storage at - 20 degrees C. No spontaneous haemolyt ic activity was observed and the sera had no bactericidal effect on any of the bacterial strains tested. Iron binding capacity of the sera was high. I ndividual variation was considerable in all the factors tested. (C) 2001 Ac ademic Press.