All shells can be contaminated with paralytic shellfish poisoning (PSP) toxins, but at variablelevels depending on the area and type of shells. The highest rate of PSP toxins registered so far is 1000

The main vectors of paralytic shellfish poisoning are bivalves that accumulate toxins through their mode of nutrition (filtration) during proliferation of toxigenic algae.
Acanthocardia tuburculatum is one of the most important bivalve molluscs which cause paralytic shellfish poisoning problems in Moroccan and Spanish Mediterranean coasts this species is capable of accumulating high levels of PSP toxins for a long time in these same tissues when microalgae producing potentionnellement toxin are not present. This presents a danger to the health of consumers.
This work is part of a cooperation agreement and scientific research between the NHRI and DINAY Company is to do a study on the contamination of the red shell (Acanthocardia tuburculatum) paralytic marine biotoxins (PSP) by dosage of these last by the biological method in mice jointly by five laboratories.
Taking into account the coefficient of variation of the method of mouse bioassay is 20% our results concluded that the comparison of results obtained by the statistical test between the different laboratories revealed no significant difference in the same commission inter responsible for monitoring the safety of marine and shellfish acknowledged in September 2008 that these results are satisfactory.
This study also allowed taking measures during internal checks and monitoring of the marine environment as expand the batch of samples and diversifies in terms of size and that each lot is the subject of several repetitive analyzes.