Studies on the Life-History of the Ascarid Porrocaecum decipiens in the Bras d'Or Lakes, Nova Scotia, Canada

Larvae of the parasitic ascarid (Porrocaecum decipiens) occurred commonly in the musculature and viscera of Atlantic cod (Gadus morhua) in the Bras d'Or Lakes. They were also present in the musculature of nine other species of teleosts and probably also in the viscera of skates (Raja sp.). Most...

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Bibliographic Details
Published in:Journal of the Fisheries Research Board of Canada
Main Authors: Scott, D. M., Black, W. F.
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 1960
Subjects:
Online Access:http://dx.doi.org/10.1139/f60-064
http://www.nrcresearchpress.com/doi/pdf/10.1139/f60-064
Description
Summary:Larvae of the parasitic ascarid (Porrocaecum decipiens) occurred commonly in the musculature and viscera of Atlantic cod (Gadus morhua) in the Bras d'Or Lakes. They were also present in the musculature of nine other species of teleosts and probably also in the viscera of skates (Raja sp.). Most larvae were longer than 20 mm. None was shorter than 10 mm, a fact which suggested the existence of some earlier intermediate host, probably an invertebrate. More than 8,000 mysids, an important food of fishes when they first become infected, were examined for nematodes. Although 110 nematodes were found, only one certainly and four dubiously appeared to be Porrocaecum. The definitive hosts were the harbour seal (Phoca vitulina) and the grey seal (Halichoerus grypus). The distribution of seals coincided with local variations in the incidence of the parasite in cod.