Experimental infection of Carassius auratus (L., 1758) with the second stage larvae of the nematode Contracaecum rudolphii Hartwich, 1964.

Susceptibility of the goldfish to infection with the newly hatched second stage larvae of Contracaecum rudolphii was investigated under laboratory condition. A week after the larvae had been placed in the fish tank, the autopsied goldfish showed the nematodes in their intestine lumen. The majority of the larvae were dead. In week 2 and 3 of exposure, the larvae were being found exclusively in the intestinal wall; in week 4 and 5, the larvae, in addition to being present in the intestinal wall, were also found in the body cavity. No larvae were found in the fish autopsied in subsequent weeks.