Modulatory effects of disease, stress, copper, TBT and vitamin E on the immune system of flatfish

The immune system can be influenced by a wide range of factors, including disease, pollutants, hormones and diet. The effects of these factors have been investigated in several flatfish species including turbot Scopthalmus maximus, flounder Platichthys flesus, dab Limanda limanda and sole Solea solea. The studies included diseased fish, the in vitro application of the stress hormone cortisol, the contaminants copper and TBT, and in vivo dietary vitamin E supplements. A range of microscopic and microplate assays to measure immunocompetence has been applied to these species in both in vivo and in vitro laboratory experiments. The results are discussed in relation to current ideas of stress in fish, the regulation of the immune system and the biomarker concept.