Evaluation of octhylphenol effect on embryo development in zebra fish (Danio rerio) and common carp (Cyprinus carpio)

摘要

Worldwide, the scientific researches performed during the last years are focused on the determination of the negative effects caused by natural and antropogeneous chemical compounds on aquatic species; these species are more exposed to most pollutants than the land species, for the simple reason that the aquatic environment is the last destination for most residues. Our research team proposed to test the toxic effect caused by octylphenol, a substance belonging to the category of polyetoxy alkiphenols, on embryo development in zebra fish (Danio rerio) and common carp (Cyprinus carpio). Zebra fish embryos were obtained in laboratory, using for this 6 fish families (6 females and 12 males).Common carp embryos were purchased from the fish farm S.C. Acva Prod S.R.L. Cefa, Bihor country; these ones were obtained by artificial reproduction. After taking and selection, the fecundated spawns were introduced in 10 Nunk culture plates of 45 ml, where we introduced 40 ml water, too. For each species, we created 3 batches, with two replications, namely: batch I – control, batch II –-1 and batch III – we added in water a concentration RIJ/-1OP. During the incubation, the Nunk plates were kept in breeding aquariums, at a temperature of 28°C for zebra fish, respectively 24°C for carp. Embryo supervision was performed with the research microscope Olympus CX41, endowed with digital photo camera and software for image analysis. Beginning with 12 hours post-fecundation, we observed a higher sensibility of zebra fish under octylphenol action, so that, between 23 and 27 hours post-fecundation, the percentage of mortality increases in batches II and III to 30%, respectively 40%. 73 hours post-fecundation, 60% of the zebra fish embryos belonging to the control batch are already eclosed, while embryos belonging to batches II and III stagnate in the advanced faringula stage and in the eclosion period. 77 hours post-fecundation, all embryos belonging to the control group are eclosed, being in the larva stage; this stage in reached only by 80%, respectively 60% of the embryos belonging to batches II and III, and only after 82 hours. In carp, embryo eclosion occurred 100% in the control group after 85 hours post-fecundation, while in batches II and III it was carried out in a proportion of 80, respectively 70%. In these two batches, the other embryos, up to 100%, stagnated in the advanced faringula stage, when they died