Copper uptake, patterns of bioaccumulation, and effects in glochidia (larvae) of the freshwater mussel (Lampsilis cardium)

Abstract

The early life stages of freshwater mussels are particularly sensitive to copper (Cu) contamination. We measured the acute toxicity, bioaccumulation, and sublethal effects of Cu in glochidia. In addition, we used radiolabeled Cu ( Cu) to examine the time-dependent kinetics of uptake over 24 h. Uptake of Cu by live and dead glochidia exposed to 0.11 μmol/L exhibited similar hyperbolic patterns over the first 40 min, indicating an adsorptive phase independent of larval metabolism. Thereafter, uptake was linear with time, with a 10-fold lower bioaccumulation rate in live than in dead animals, representing a close to steady state of Cu regulation. In contrast, dead glochidia exhibited a progressively increasing uptake, possibly attributable to the fact that metal-binding sites become more accessible. Mortality was strongly correlated with bioaccumulation (48 h); live glochidia exposed to Cu concentrations>0.27 μmol/L lost their regulatory ability and accumulated Cu to an even greater extent than dead animals. Exposure to Cu induced significant decreases in whole-body Na and Mg concentrations; increases in reactive oxygen species concentration, lipid peroxidation, and protein carbonylation; and a decrease in antioxidant capacity against peroxyl radicals. Overall, these results clarify the patterns of Cu uptake and regulation, emphasize the importance of distinguishing between live and dead larvae, and indicate that toxicity is associated with Cu bioaccumulation, involving both ionoregulatory disturbance and oxidative stress. Environ Toxicol Chem 2018;37:1092-1103. © 2017 SETAC.

The Genomic Potentials of NOB and Comammox Nitrospira in River Sediment Are Impacted by Native Freshwater Mussels

“…One explanation for these findings may be related to mussels hosting antibiotic resistant symbionts ( Cooke, 1976 ; Liu et al, 2016 ), multidrug-resistant pathogens, ( da Silveira et al, 2016 ), and enhanced horizontal gene transfer within their gut microbial community ( Grevskott et al, 2017 ). Previous research has also shown that mussels bioaccumulate various metals ( Naimo, 1995 ; Rzymski et al, 2014 ), including elements found in this genetic marker study, copper and zinc ( Jorge et al, 2018 ). It is possible that horizontal gene transfer of multidrug resistance was facilitated by symbionts in mussel biodeposits, or from the decay of mussel tissue after death.…”

The effect of copper and chlorpyrifos co-exposure on biomarkers in the marine mussel Mytilus galloprovincialis

“…This process may eventually lead to formation of LPO and impairment of membrane function (Halliwell and Gutteridge, 2006). Exposure of M. galloprovincialis to Cu alone did not result in LPO level increase although a strong pro-oxidant activity of Cu was previously reported for bivalves (Jorge et al, 2018;Katsumiti et al, 2018).…”

Modelling chronic toxicokinetics and toxicodynamics of copper in mussels considering ionoregulatory homeostasis and oxidative stress

“…Among aquatic organisms, freshwater mussels are highly sensitive to acute Cu exposure (Wang et al, 2011;Giacomin et al, 2013), while bivalve mussels have been widely deployed in ecotoxicology studies (Caricato et al, 2019). Chronic exposure to Cu at sublethal concentrations might lead to both ionoregulatory disturbance and oxidative stress in freshwater bivalves (Jorge et al, 2013(Jorge et al, , 2018. The activity of the osmoregulatory enzymes Na + /K + -ATPase (NKA) has been investigated as a potential target of Cu effects (Jorge et al, 2013(Jorge et al, , 2018Fan et al, 2016).…”

“…Chronic exposure to Cu at sublethal concentrations might lead to both ionoregulatory disturbance and oxidative stress in freshwater bivalves (Jorge et al, 2013(Jorge et al, , 2018. The activity of the osmoregulatory enzymes Na + /K + -ATPase (NKA) has been investigated as a potential target of Cu effects (Jorge et al, 2013(Jorge et al, , 2018Fan et al, 2016).…”