Development of larval Contracaecum rudolphii Hartwich, 1964 (Ascaridida: Anisakidae) in experimentally infected goldfish (Carassius auratus L., 1758).
Laboratory-bred goldfish were experimentally infected with Contracaecum rudolphii, either directly (with nematode larvae) or indirectly via infected zooplankton. Intensity and prevalence of infection were markedly higher in fish exposed to the infected zooplankton than in goldfish exposed to nematode larvae. When transmitted to fish via the zooplankton, larvae developed much faster and, after 8 weeks, became firmly encysted in the intestine wall. The digestive tract of larvae isolated from the intestine wall showed a well-developed ventriculus, ventricular appendix and intestinal caecum. The mouth was surrounded by three lips. When free-living larvae induced infection, they rapidly penetrated the intestine wall and migrated to internal organs (e.g. liver). The primordial lips of those larvae were poorly visible, the ventricular appendix was short, and the intestinal caecum was absent. During the 10-week experiment, no encysted larvae were found in fish infected with free-living larvae.
Dziekońska-Rynko
J
J
Department of Zoology, Faculty of Biology, University of Warmia and Mazury in Olsztyn, 10-957 Olsztyn, Poland. jdr@uwm.edu.pl
Rokicki
J
J
Gomułka
P
P
D000818:Animals; D017162:Ascaridida / Q000254:growth & development* / Q000502:physiology; D017191:Ascaridida Infections / Q000469:parasitology / Q000662:veterinary*; D005260:Female; D005393:Fish Diseases / Q000469:parasitology*; D006054:Goldfish / Q000469:parasitology*; D007422:Intestines / Q000469:parasitology; D007814:Larva / Q000254:growth & development / Q000502:physiology; D008297:Male