Effects of water pH on copper toxicity to early life stages of the common carp (Cyprinus carpio)

Abstract

X a n d e r J .H .X . S t o u t h a r t ,* J e r o e n L .M . H a a n s , R o b e r t A .C . L o c k a n d A bstract-Carp eggs were exposed immediately after fertilization to Cu concentrations of 0.3 and 0,8 (xmol/L at water pH 7.6 or pH 6.3. Mortality, the incidence of spina! cord deformation, heart rate, tail movements, hatching success, and whole-body content of K, Na, Mg, Ca, and Cu were determined over time. Light microscopical preparations of eggs (48 h after fertilization) and larvae (168 h after fertilization) were studied. At pH 7.6, Cu did not affect egg mortality, heart rate, tail movements, and whole-body K and Mg content. Hatching success increased only in the 0.3 fimol/L Cu group. Exposure to 0.8 (junol/L Cu increased larval mortality and larval deformation and decreased whole-body Na and Ca content. At pH 6.3, exposure to 0.8 |j.mol/L Cu increased egg mortality and decreased heart rate and tail movements. Furthermore, premature hatching, a concentration-dependent increase of larval mortality, and larval deformation was observed. Exposure to 0.3 and 0.8 p.mol/L Cu decreased the whole-body content of K, Na, Mg, and Ca. Uptake of Cu after hatching increased two-fold at pH 6.3 compared to the pH 7.6 groups. At pH 6.3, all Cu-exposed larvae were unable to fill their swim bladder. Also, after 168 h the yolk sac remained largely unabsorbed in the 0.3 and 0.8 ixmol/L Cu group. Exposure to 0,8 (xmol/L Cu resulted in coagulation of proteins in eggs and yolk sacs. No significant changes in any of the assessed parameters were observed in control groups of pH 6.3 and pH 7.6.

Hypoxia Suppressed Copper Toxicity during Early Development in Zebrafish Embryos in a Process Mediated by the Activation of the HIF Signaling Pathway

“…This increase in copper content was linked with the presence of the chorion, and in dechorinated embryos there were no changes in copper concentration in exposed embryos compared to controls. The chorion is known to bind copper, providing a barrier preventing copper from reaching the embryonic cells. − In addition, hypoxia did not affect copper concentrations in embryos with or without the chorion demonstrating that this is unlikely to be the mechanism responsible for the hypoxia-induced reduction in copper toxicity during early development. This is supported by the measured transcript profiles for atp7a , which indicated that there were no alterations in the transcription of this key copper transporter .…”

Health Impact Assessment of Sulfolane on Embryonic Development of Zebrafish (Danio rerio)

“…In the present study yolk sac utilisation, larval length and eye volume have decreased by 120 hpf, indicating possibility of delayed development following sulfolane exposure. Previous studies have also demonstrated that contaminants may alter the rate of yolk sac utilisation and as such makes it a good indicator of delayed development [62,63,64].…”

Acute and chronic sensitivity to copper of a promising ecotoxicological model species, the annual killifish Nothobranchius furzeri

“…However, this buoyancy problem occurred much faster in the highest copper concentration C5, with 38% suffering this condition only six hours after the start of the exposure. Loss of buoyancy was also observed in Common Carp (Cyprinus carpio) exposed to copper (Stouthart et al 1996). In Common Carp and Gibel Carp (Carassius auratus gibelio), copper exposure led to cell swelling in the gills, an effect seen more often in copper-exposed fish.…”