Month Purification time (hours) NRR*     Mussels parasitized with Marteilia spp. Marteilia-free mussels   0 21 30 May 24 28 38   48 26 40   0 17 47 June 24 30 30   48 24 23   0 21 38 October 24 21 29   48 24 27

*expressed as number of stable cells out of 50

Table 3: Results of the Neutral Red Retention Test performed on parasitized and parasite-free mussels (M. galloprovincialis) at different purification times.