Biochemical and Behavioural Alterations Induced by Arsenic and Temperature in Hediste diversicolor of Different Growth Stages

Abstract

Contamination with Arsenic, a toxic metalloid, is increasing in the marine environment. Additionally, global warming can alter metalloids toxicity. Polychaetes are key species in marine environments. By mobilizing sediments, they play vital roles in nutrient and element (including contaminants) cycles. Most studies with marine invertebrates focus on the effects of metalloids on either adults or larvae. Here, we bring information on the effects of temperature increase and arsenic contamination on the polychaete Hediste diversicolor in different growth stages and water temperatures. Feeding activity and biochemical responses—cholinesterase activity, indicators of cell damage, antioxidant and biotransformation enzymes and metabolic capacity—were evaluated. Temperature rise combined with As imposed alterations on feeding activity and biochemical endpoints at different growth stages. Small organisms have their antioxidant enzymes increased, avoiding lipid damage. However, larger organisms are the most affected class due to the inhibition of superoxide dismutase, which results in protein damage. Oxidative damage was observed on smaller and larger organisms exposed to As and temperature of 21 °C, demonstrating higher sensibility to the combination of temperature rise and As. The observed alterations may have ecological consequences, affecting the cycle of nutrients, sediment oxygenation and the food chain that depends on the bioturbation of this polychaete.

The Role of Life Stages in the Sensitivity of Hediste diversicolor to Nanoplastics: A Case Study with Poly(Methyl)Methacrylate (PMMA)

“…An H. diversicolor burrowing impairment could provide information on the potential increased susceptibility of these organisms (e.g., inability to avoid predators), as well as on potential effects on the community [77], since a potential impact or total impairment of burrowing/feeding activity affects nutrient resuspension and the oxygenation of sediment. In this study, no mobility issues were observed during burrowing assays, with organisms moving in circular motions along the edge of the container; therefore, the inability to move cannot be the reason for their altered burrowing behavior.…”

“…However, the present study revealed that juveniles showed high sensitivity to protein damage, with a general significant increase in PC levels in exposed organisms indicating that SOD, CAT, and GST activities, although increased, could not prevent oxidative damage. These endpoints have been shown to be sensitive in H. diversicolor exposed to arsenic [77] and to the combination of arsenic and PS NPs [96], Ficopomatus enigmaticus exposed to carboxylated carbon nanotubes [97], and Diopatra neapolitana worms exposed to trace elements (arsenic, zinc, iron, manganese, lead, and tin) [98]. LPO, a parameter associated with greater production of free radicals, which can lead to an increase in the permeability of the cell membranes, rupture, and possible cell death, was, in general, lower than in the controls.…”