Bioaccumulation and depuration of anthracene in Penaeus monodon (Fibricius) through food ingestion

Persistent organic pollutants (POPs) in marine crustaceans: Bioaccumulation, physiological and cellular responses

Persistent organic pollutants (POPs) are ubiquitous in marine ecosystems. These compounds can be accumulated in water, sediments and organisms, persist in time, and have toxic effects in human and wildlife. POPs can be uptaken and bioaccumulated by crustaceans, affecting different physiological processes, including energy metabolism, immunity, osmoregulation, excretion, growth, and reproduction. Nonetheless, animals have evolved sub-cellular mechanisms for detoxification and protection from chemical stress. POPs induce the activity of enzymes involved in xenobiotic metabolism and antioxidant systems, that in vertebrates are importantly regulated at gene expression (transcriptional) level. However, the activation and control of these enzyme systems upon the exposure to POPs have been scarcely studied in invertebrate species, including crustaceans. Herein, we summarize various aspects of the bioaccumulation of POPs in marine crustaceans and their physiological effects. We specially focus on the regulation of xenobiotics metabolism and antioxidant enzymes as key sub-cellular mechanisms for detoxification and protection from chemical stress.

Using a multibiomarker approach and behavioural responses to assess the effects of anthracene in Palaemon serratus

Polycyclic aromatic hydrocarbons (PAHs) are recognised as one of the main groups of contaminants that assume more importance in the marine environment, enhancing the need of studies concerning their adverse effects and more efficient and ecologically relevant tools for environmental monitoring purposes. This study aims to apply an integrated approach including several multi-level biological responses (accumulation levels, biochemical responses important for different physiological functions and behavioural alterations) to assess the ecological relevance of the effects induced by sub-lethal concentrations of anthracene (ANT) in Palaemon serratus (common prawn). ANT accumulation was assessed by measuring the levels of ANT-type compounds in prawn digestive gland, muscle and eye; biochemical responses were determined using biomarkers involved in biotransformation, oxidative damage, energy production and neurotransmission processes; and behavioural alterations through swimming performance after 96 h exposure bioassay (ANT:16-1,024 μg/L). The rationale behind this approach is to assess the ecologically relevant effects induced by ANT in prawn, given by the association between behavioural alterations with biochemical responses, in search for more efficient tools for environmental risk assessment. Results show a significant decrease of swimming velocity (LOEC=128 μg/L) along with increased levels of ANT-type compounds in digestive gland (LOEC=128 μg/L), muscle (LOEC=256 μg/L) and eye (LOEC=32 μg/L) in prawn exposed to ANT. Increased activities of glutathione peroxidase (GPx) and catalase (CAT), involved in anti-oxidant defence system, were also observed (LOEC=256 μg/L; 1024μg/L, respectively) in the digestive gland of prawn, induction of oxidative damage in lipids (LPO) also occurred (LOEC=32 μg/L). The inhibition of swimming velocity showed a correlation with some biochemical parameters measured, including the levels of ANT-type compounds in tissues and LPO, and thus these may be considered sensitive and ecologically relevant criteria as well as early warning endpoints for assessing polycyclic aromatic compounds exposure effects on marine organisms.