Fish are thoroughly inspected looking for external parasites (ectoparasites of the gills, oral cavity or tegument). Then, fish are dissected to look for internal parasites (endoparasites). The dissection is performed on board or in the different laboratories of the partners (Ifremer Nantes, ANSES Boulogne s/mer, PFI Nouvelles Vagues).

The following steps are achieved following a standardized protocol:

•    To identify the fish species
•    To weigh and measure the fish
•    To isolate and number the parasites per organ
•    To preserve the parasites (ethanol 70% for molecular detection of Anisakidae and other worms)
•    To preserve the intestinal contents in a 2,5% potassium dichromate (K₂Cr₂O₇) solution (to preserve the viability of Cryptosporidium spp. oocysts)
•    To scrap the intestinal and stomachal mucosa in RCL2 solution (for molecular detection of Cryptosporidium spp.)
•    To take a piece of intestinal and stomachal mucosa in 10% buffered formol for later histological studies
•    To store the fish fillets at -20°C for later pepsic digest (to isolate Anisakidae larvae)