1Toralla Marine Science Station (ECIMAT) E-36331 Vigo, Galicia, Spain
2Hydrobiology Unit, Environmental Biomonitoring Laboratory, Faculty of Sciences Bizerte, University of Carthage, Zarzouna 7021, Tunisia
In the present study, the toxic effects on the embryos and larvae of the turbot were used as a
model to investigate the diazinon, which contaminates aquatic ecosystems. The number of dead embryos significantly increased in response to diazinon concentrations 0.2, 0.4, 0.8, 1.6, 3.2, and 7.4 mg/L. The 48h LC50 value of diazinon for turbot embryos was estimated at 1.85 mg/L. Dose–response decreases in hatching success were recorded as 97, 92.4, 80.3, 60.3, 38.7 and 27.1%, respectively. The number of dead larvae significantly increased with increasing diazinon concentrations exposed for 24–96 h (p < 0.05). The 24, 48, 72 and 96h LC50 values of diazinon for turbot larvae were estimated at 4.8 (6.4-5.12), 3.3 (4.73-2.52), 2.1 (3.29- 1.65) and 1.23 (0.87–2.38) mg/L, respectively. There were significant differences in the LC50 values obtained
at different exposure times (p <0.05). Diazinon caused lethal toxicity as well as nonlethal malformations during embryo-larvae development.