[Immunologic observations in fishes of the genus Mugil parasitized by the myxosporidan Myxobolus exiguus Thélohan, 1895 (author's transl)].

This investigation was undertaken to find antibodies to the myxosporidan Myxobolus exiguus Thélohan, 1895 in the serum of Mugils (Pisces, Teleostei). The few previous studies dealing with immunology of myxosporidiosis have yielded negative results. We thought that the methods used were responsible for these results. Therefore, we prepared a lyophilized antigen from the Myxosporidian spores with which we injected rabbits and a fish. In the rabbits these antigens evoked a response which, although too weak for detection by the gel precipitation method, was clearly demonstrable by the complement fixation technique. In contrast we did not detect any response in the fish. It thus appears that in the fish there is no production of precipitating or complement fixing antibodies against Myxosporidia. We found, however, that the fish serum behaves, in reaction with the immune rabbit serum, as though it contained the antigen.