IMMUNOHISTOCHEMICAL CHARACTERIZATION OF A POLYCLONAL ANTIBODY AGAINSTSPHAEROSPORA-DICENTRARCHI (MYXOSPOREA, BIVALVULIDA), A PARASITE FROM SEA BASS (DICENTRARCHUS-LABRAX L.) (TELEOSTEI, SERRANIDAE)

Rabbit antibody was raised against Sphaerospora dicentrarchi, a histoz oic parasite of sea bass (Dicentrarchus labrax L.). Light and electron immunohistological staining were used to characterize its specificity and possible reactivity toward other fish parasites. In light immunoh istochemistry the polar capsules and valves of the S. dicentrarchi spo res appeared strongly stained, whereas developmental stages were not. Electron microscopic histochemistry revealed intense labeling in valve s and some developmental stages. Cross-reaction was observed with all the myxosporean parasites assayed, even with those belonging to other genera. Polar capsules of all the myxosporean species except Polysporo plasma sparis were the main structures stained by the polyclonal antib ody. These observations could reveal the existence of conserved antige nic epitopes in polar capsules of different Myxosporea.