Effects of dietary cadmium exposure on reproduction of saltwater cladoceran Moina monogolica Daday: Implications in water quality criteria

Abstract

The chronic toxicity of dietary cadmium to the saltwater cladoceran Moina monogolica Daday and its relative toxicity compared with aquatic exposure were investigated in the present study. The microalgae Chlorella pyrenoidosa, exposed to cadmium in growth inhibition tests, had a 96-h median effective concentration (EC50) of 81.2 microg Cd/L (95% confidence intervals [CIs] = 71.9-95.1). C. pyrenoidosa exposed for 96 h to sublethal dissolved cadmium concentrations in the range 4.10 +/- 0.30 to 70.29 +/- 0.31 microg/L resulted in algal cadmium burdens up to 73.86 x 10(-16) g Cd/cell. Cellular cadmium burdens accumulated in a dose-dependent manner, whereas cell densities inversely declined from 670 x 10(4) to 38 x 10(4) cells/ml with exposure to the increasing aqueous cadmium concentrations. C. pyrenoidosa preexposed to cadmium and used as food in a chronic 21-d toxicity test with the cladoceran M. monogolica, containing no added dissolved cadmium, inhibited reproduction. Significant reductions of the net reproduction rate (R(0)) per brood were observed in all broods, and the decline in the number of neonates produced increased with each subsequent brood. The cadmium concentration (4.10 +/- 0.30 microg/L) in the algal culture water that produced the lowest algal cadmium burden (2.85 +/- 0.76 x 10(-16) g Cd/cell) was shown to inhibit M. monogolica reproduction and was compared with the water quality criteria (WQC) of China. This comparison indicated that dietary exposure to cadmium may cause sublethal responses at concentrations below the current cadmium WQC of China for aquaculture.

Effects of dietborne cadmium on life history and secondary production of a tropical freshwater cladoceran

“…Several studies have demonstrated the importance of dietborne in metal exposure and toxicity to zooplankton. Production of neonates by Daphnia magna was significantly reduced when its diet (Pseudokirchneriella subcapitata) was contaminated with Cd (Geffard et al 2008); toxic effects were observed on the survival and reproductive aspects of Moina monogolica fed on Cd contaminated Chlorella pyrenoidosa (Wang et al 2010). Similar effects on fecundity and survival were reported for other daphnid species like Ceriodaphnia dubia (Rodgher and Espíndola 2008).…”

Integrated assessment of biomarker responses in caged shrimps (Litopenaeus vannamei) exposed to complex contaminants from the Maluan Bay of China

“…However, zinc concentrations in the hepatopancreas from all deployment sites were in the same range as those reported for the reference site. One possible reason is that the shrimp have developed mechanisms to regulate accumulation of zinc as essential metal or the organisms taken from the aquaculture farm had a high background concentration of zinc (Wang et al 2010). Surprisingly, zinc concentrations were much lower than copper concentrations in the hepatopancreas of L. vannamei, which is different from the relationships between zinc and copper concentrations in tissues of other organisms such as bivalves.…”

Concentrations of some heavy metals in water, suspended solids, and biota species from Maluan Bay, China and their environmental significance

“…The suspended solids in the water are a mixed collection of different materials, resuspended sediment, colloids, fecal material, organic decomposition materials, etc., which can easily adsorb metals and could constitute a source of contamination and toxicity for aquatic organisms (Wang et al 2010). As one component of aquatic ecosystems that are important for metal transport, suspended solids can produce more direct impacts on aquatic ecosystems and can reflect the real-time status of water pollution as a better indicator than sediment (Zhu et al 2005).…”