Co-infections of tapeworm larvae Sobolevicanthus gracilis [Zeder, 1803] and Fimbriaria czaplinskii Grytner-Ziecina, 1994 in Heterocypris incongruens [Ostracoda]

In subsequent co-infections of Sobolevicanthus gracilis and Fimbriaria czaplinskii an elimination of the majority of specimens of the first species by the next one has been found at the early stage of development. This did not depend on the fact, which species was the first. In concurrent control co-infections of larvae of both species mentioned above developed simultaneously and correctly. It seems to testify the existence of interspecific competition expressed by a peculiar sensibility of larvae at their early stages of development (3rd to 5th day post infection). The longer the larvae of the first species develop the fewer of them become eliminated by the next one.