Differential response of biomarkers in the native European flat oyster Ostrea edulis and the non-indigenous Pacific oyster Crassostrea gigas co-exposed to cadmium and copper

Development of a toxicokinetic-toxicodynamic model simulating chronic copper toxicity to the Zebra mussel based on subcellular fractionation

“…A lack of a significant increase in the GST activity and LPO in the Zebra mussel in the present study indicates an adequate response of the antioxidant defence system to the generation of ROS. This conclusion was also recently obtained in assessing the response of oysters exposed to Cd (Peric et al, 2020). Furthermore, oxidative stress-related biomarker responses, such as LPO and GST activity, should be related to toxicological effects in the next step.…”

“…Previous studies did not show a consistent trend in the changes of the GST activity or the LPO level in bivalves in response to metals. For example, Peric et al (2020) proposed that a lack of alleviative effects on the GST activity and the LPO level might be attributed to the involvement of ROS-scavenging enzymes. Such variations in biomarker responses exert high uncertainty in TD modelling, as exemplified by the relationship between metal concentrations at sites of toxic action and biomarkers in the present study.…”

Impact of Polycyclic Aromatic Hydrocarbon Accumulation on Oyster Health

“…Due to the fact that oysters live amongst potentially contaminated sediments, and are filterfeeders that clear particles from large volumes of seawater each day (National Research Council, 2004), oysters are likely exposed to many times more contaminants than either non-filter-feeders or nekton that do not live near the sediments. Despite this, oysters continue to thrive due to their resilience to pollutants with several studies such as dos Reis et al (2015) reporting no mortalities after exposing C. brasiliana to up to 1,000 µg L −1 phenanthrene (Phe) for up to 10 days, Perić et al (2020) reporting no mortalities after exposing O. edulis and M. gigas to up to 100 µg L −1 copper and 50 µg L −1 cadmium for up to 4 days, and Aguirre- Rubí et al (2018b) demonstrating that oysters stayed alive for as long as 10 days without water despite exhibiting possible contaminant-induced digestive gland atrophy and hemocytic infiltration of interstitial connective tissue. Thus their ability to survive despite the pollution while exhibiting measurable responses to it, combined with their distribution, living habits, and multiple life stages make oysters an exceptionally favorable bioindicator organism (Zhou et al, 2008).…”

“…Wang et al (2020) break down the oyster anatomy into five portions: adductor, gill, gonad, hepatopancreas, and mantle. In other studies, the hepatopancreas is often referred to as the digestive gland (Bustamante et al, 2012b;Vaschenko et al, 2013;dos Reis et al, 2015;Shenai-Tirodkar et al, 2017;Aguirre-Rubí et al, 2018b;Perić et al, 2020;Shao and Wang, 2020) and the adductor is referred to as "muscle" (Bustamante et al, 2012b). The use of "soft tissues" is much more vague as it likely refers to gonads and mantle (Shao and Wang, 2020), non-gill tissue (Chan and Wang, 2019), or even all tissues combined and sometimes called either "total" or "whole" soft tissues (Aguirre-Rubí et al, 2018b;Sezer et al, 2018;Wang et al, 2020).…”

“…This possibly suggests a preferential pathway of CBR reduction (Ertl et al, 2016) or a lack of need for AKRs in PAH breakdown. As for the downregulation of GST, it should be noted that such ambiguous phenomenon was observed in O. edulis and M. gigas by Perić et al (2020) following the exposure of heavy metals Cu and Cd, and that antioxidant or metabolic enzymes should not be exclusively relied upon as biomarkers of PAH exposure. The lack of any change in CYP, GST, SULT, SOD, CAT, and GPx transcripts and/or activity in This non-exhaustive list provides a collection of common end points used to study chemical toxicity and some of the effects of the contaminants that may manifest in a less controlled setting.…”