Ecotoxicology and innate immunity in fish

This review summarizes the scattered literature on the effects of toxicants on the external and internal innate immunity of fish. Insecticides, heavy metals and surfactants have been the most frequently examined toxicants, wh ereas dioxins, furans and polychlorinated biphenyls have been tested less f requently. Studies to date have been conducted at the levels of cells in vi tro, of fish in the laboratory and microcosms, and also of fish in the fiel d. Among innate immune parameters, phagocyte respiratory burst appears espe cially sensitive to toxicants. Toxicant-induced alterations in external muc ous production have also been observed repeatedly. Field studies have occas ionally examined changes to melano-macrophage centers, but the meaning of s uch changes is not clear. Advances in basic knowledge of fish innate immuni ty should lead to improvements in monitoring fish health and predicting the impact of toxicants on fish populations, which is a fundamental ecotoxicol ogical goal. (C) 2001 Elsevier Science Ltd. All rights reserved.