Antifreeze activity in body fluids of some marine fishes from the Disko Bay and Disko Fjord

The presence of macromolecular antifreezes (thermal hysteresis factors) in blood serum and gut fluids of marine teleost fishes from West Greenland waters was investigated in August 1997, during a NorFa Fish Physiology Course.

Thermal hysteresis in oc in the serum of five shallow water {depth < 50 m) species was: Anisarcus medius (1.27), Pholis fasciatus (0.51±0.27), Gymnachantus tricuspis (0.50±0.11), Myoxocephalus scorpius (0.42) and Gadus ogac (0.40±0.09). O n ly two of the species caught in deep water (depth 300-500 m), Boreogadus saida and Leptoclinus maculatus, showed considerable thermal hysteresis of 0.87 o c and 0.98 oc, respectively. No thermal hysteresis was found in three shallow water species (Ammodytes dubius, Gadus morhua and Anarchias lupus) and eight species caught in deep water (300-500 m): Mallotus villosus, Artedielius atlanticus, Leptagonus decagonus, Sebastes sp., Liparis gibbus, Caraproctus fabrici, Lycodes seminudus and Lycodes vah/i).

This is probably the first time that thermal hysteresis has been reported for Leptoclinus maculatus, Anisarcus medius, Pho/is fasciatus and Gymnachantus tricuspis.