The abundance and distribution of Diphyllobothrium dendriticum (Nitzsch) and D. ditremum (Creplin) in the char Salvelinus alpinus (L.) in Sweden

• Published in: Journal of Fish Biology
• Main Author: Henricson, Jan
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1977
• Subjects: Salvelinus alpinus
• Online Access: http://dx.doi.org/10.1111/j.1095-8649.1977.tb04116.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1095-8649.1977.tb04116.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1095-8649.1977.tb04116.x

A total of 654 char, Salvelinus alpinus (L.) and 33 brown trout, Salmo trutta L., were examined for the plerocercoids of Diphyllobothrium dendriticum (Nitzsch, 1824) and D. ditremum (Creplin, 1825). Only char were found to be infected. Both parasitic species were abundant. The incidence and mean intensity of infection for D. dendriticum were 83.2% and 8.8, respectively; for D. ditremum 93.7% and 45.0. There was no variation in the intensity of infection between different parts of the lake. The incidence and intensity of infection increased with the age of the fish to age 8+ for both species. From this age the intensity of infection leveled off or decreased. No differences in intensity of infection between the sexes were found. The frequency distribution of parasite counts were overdispersed and fitted the negative binomial distribution even within single age‐groups. The two parasite species showed a high positive correlation in intensity of infection, D. ditremum was concentrated in the stomach and pyloric caeca. D. dendriticum was more widely distributed within the host and was supposed to kill heavily infected fish.