MUSSELS STRESS MARKERS: USEFUL TOOLS TO MONITORING THE PRODUCT QUALITY?

The stress represents a disruption of the physiological steady state of the organism, known as homeostasis, and severalmorphological and physiological markers have been investigated as useful tools to measuring the effects of a variouskind of stressors on the homeostasis condition. The marine bivalve molluscs play a key role as sentinel organisms in theenvironmental monitoring for their sedentary and filter-feeding characteristics. In addition, they have an important role aseconomic source in many countries and in the widespread food consumption.The molluscs can suffer the environmental stress due to the growing areas conditions (temperature, dissolved oxygen,salinity, pollutants, etc.) and the homeostasis disruption could take to deleterious effects for natural beds or shellfishfarming, in terms of natural mortality or increased susceptibility to pathogens.Furthermore, bearing in mind the molluscs intended for immediate human consumption must comply with the possessionof visual characteristics associated with freshness and viability, stress conditions linked to the successive processing stageslocated before the placing on the market (harvesting, transportation, relaying, depuration, handling, storage, etc.) couldstraight affect the product quality.The mussels play an important economic role in the worldwide shellfish farming and various morphological or functionalmarkers have been proposed for monitoring the negative impact of the stressors on the mussel homeostasis.In particular, the invertebrate immune system represents a suitable model for understanding the stress effects. In fact, thestress can modulate the properties of the phagocytic cells, known as hemocytes, in terms of pseudopodia emission andreactive oxygen species (ROS) synthesis. In this sense, the cell behaviour computerized analysis, the flow cytometry andspecific micromethod assays could represent innovative methods for measuring the hemocyte spreading, phagocytosisactivities and their modulation linked to the stress.Furthermore, among the several proteins implied in the assessment of the stress response, the heat shock proteins (HSPs70 kDa) represent a class of highly conserved proteins and various field and experimental studies have confirmed theirinduced protective role following exposure to different kind of stressors. The possibility to develop genetic probes, specificmonoclonal antibodies and useful tools starting from the purified protein could supply more accurate information aboutthe stress response.In conclusion, the stress parameters in bivalve molluscs could represent useful tools applied not only to the environmentalmonitoring, but also in the management of the shellfish farming and food quality assessment.[...