Toxicity of mercury, copper, nickel, lead, and cobalt to embryos and larvae of zebrafish,Brachydanio rerio

Abstract

The toxicity of mercury (HgCl2), copper (CuCl2: 5 H20), nickel (NiSO4: 6 H2O), lead (Pb(CH3COO)2: 3 H2O) and cobalt (CoCl2: 6 H2O) was studied under standardized conditions in embryos and larvae of the zebrafish, Brachydanio rerio. Exposures were started at the blastula stage (2-4 h after spawning) and the effects on hatching and survival were monitored daily for 16 days. Copper and nickel were more specific inhibitors of hatching than cobalt, lead, and mercury. Nominal "no effect" concentrations determined from the dose-response relationships (ZEPs, Zero Equivalent Points) for effect on hatching time were 0.05 microgram Cu/L, 10 micrograms Hg/L, 20 micrograms Pb/L, 40 micrograms Ni/L and 3,840 micrograms Co/L, and those for effect on survival time were 0.25 microgram Cu/L, 1.2 micrograms Hg/L, 30 micrograms Pb/L, 80 micrograms Ni/L, and 60 micrograms Co/L. The "no effect" concentrations for Ni, Hg and Pb are consistent with previously reported MATC values for sensitive species of fish. The "no effect" concentrations for copper are 1-2 orders of magnitude lower than previously reported values. The major reason for the latter discrepancy was considered to be the absence of organics that can complex copper ions in the reconstituted water that we used, which had a hardness of 100 mg/L (as CaCO3) and a pH of 7.5-7.7. Unexposed controls were started with embryos from different parental zebrafishes and the parental-caused variability in early embryo mortality, median hatching time and median survival time were estimated.

Postsettlement survival linked to larval life in a marine fish

“…These are far below levels considered toxic for larval fishes (30 g liter Ϫ1 , ref. 46) and are unlikely to deleteriously affect physiological performance. Significantly elevated Pb/Ca concentrations occurred at the end of larval development for the low-Pb group, signifying a change in water mass.…”

Sublethal concentrations of waterborne copper induce cellular stress and cell death in zebrafish embryos and larvae

“…Zebrafi sh have been widely used for detection of heavy metal contamination, making this animal a convenient biological water contaminant sensor (Blechinger et al, 2002b;Chan and Cheng 2003;Dave and Xiu 1991;Li et al, 2004;Ribeyre et al, 1995;Rougier et al, 1996). However, there is little information on the effects of copper on early fish development and its potential toxicity at sub-lethal concentrations (around 5 μM of Cu) (Hernandez et al, 2006;Sandahl et al, 2007;Seok et al, 2006).…”

“…To date, substantial information has been accumulated on the effects of metals like copper, cadmium, mercury and other heavy metals in organisms (Blechinger et al, 2002b;Coronado et al, 2001;Dave and Xiu 1991;Gravenmier et al, 2005;Szebedinszky et al, 2001). Two disorders in humans are associated with either lack or excess of copper in the organism.…”

TOXIC AND TERATOGENIC EFFECTS OF COPPER SULPHATE ON THE DEVELOPING EMBRYOS AND LARVAE OF SILVER CARP, HYPOPHTHALM1CHTHYS MOLITRIXVAh. AT TWO TEMPERATURES

“…Runn et ah, 1977 andHagenmaier, 1974 , reported that the main limiting factors of fish development are the mechanisms involved in the hatchery process. These mechanisms are Toxic and teratogenic effects of copper sulphate on the 239 developing embryos and larvae of silver carp connected with digesting of the egg envelope by chorionase enzyme, Dave and Xiu (1991) stated that delayed hatching of zebrafish exposed to copper might have resulted from osmoregulatory disturbances affecting the embryo muscles and inhibiting of chorionase.…”