Multiscale approach of fish responses to different types of environmental contaminations: a case study.

In order to study the responses of wild fish to environmental contaminations, different sites (two references and three contaminated) were sampled across the Walloon hydrographical network (southern Belgium). The status of fish communities was characterized according to an index of biotic integrity (IBI). Furthermore, population structure, reproductive parameters and biochemical assays were performed on chub (Leuciscus cephalus) as sentinel species.

Effects of microcystins on fish.

Microcystins (MCs) are hepatotoxic heptapeptides released into water during or on senescence of cyanobacterial blooms. This review details the different effects of the MCs on fish and discusses their potential consequences in aquatic food webs. In early life stages, exposure to MCs causes, in a dose-dependent manner, perturbations to embryonic hatching, decrease in survival and growth rate, as well as histopathological effects (enlarged and opaque yolk sac, small head, curved body and tail, hepatobiliary abnormalities, ultrastructural alterations in hepatocytes, heart rate perturbations).

Effect of microcystin-LR on protein phosphatase activity and glycogen content in isolated hepatocytes of fed and fasted juvenile goldfish Carassius auratus L.

Toxic effects of microcystin-LR were studied in hepatocytes isolated from fed and fasted juvenile goldfish Carassius auratus (30 g body weight). The hepatocytes were incubated with 10 microgMC-LR l(-1) during 4 h. MC-LR induces no effect in terms of cell number and viability.

Effect of microcystin-LR on protein phosphatase activity in fed and fasted juvenile goldfish Carassius auratus L.

Fed and fasted juvenile goldfish Carassius auratus (30 g body weight) were injected intraperitoneally (i.p.) with microcystin-LR (MC-LR) (125 microg/kg body weight) to determine the effect of alimentary status on the hepatic toxicity of MC-LR.

Hepatic accumulation and effects of microcystin-LR on juvenile goldfish Carassius auratus L.

After intraperitoneal injection of microcystin-LR (MC-LR) (125 microg kg(-1) body wt.), the concentration of MC-LR in the liver of juvenile goldfish Carassius auratus (30 g body wt.) was assayed by a modified protein phosphatase inhibition method.