Variation in the Incidence of Larval Nematodes in Atlantic Cod Fillets along the Southern Canadian Mainland
The incidence of larval nematodes, Porrocaecum decipiens, in fillets from three size-groups (scrod, market and steak) of Atlantic cod, Gadus callarias, has been analyzed. The analysis was based on about 73,000 fillets from cod caught between 1946 and 1956 in about 20 areas off the southern Canadian...
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crcansciencepubl:10.1139/f57-043 2023-12-17T10:27:03+01:00 Variation in the Incidence of Larval Nematodes in Atlantic Cod Fillets along the Southern Canadian Mainland Scott, D. M. Martin, W. R. 1957 http://dx.doi.org/10.1139/f57-043 http://www.nrcresearchpress.com/doi/pdf/10.1139/f57-043 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Journal of the Fisheries Research Board of Canada volume 14, issue 6, page 975-996 ISSN 0015-296X General Medicine journal-article 1957 crcansciencepubl https://doi.org/10.1139/f57-043 2023-11-19T13:38:11Z The incidence of larval nematodes, Porrocaecum decipiens, in fillets from three size-groups (scrod, market and steak) of Atlantic cod, Gadus callarias, has been analyzed. The analysis was based on about 73,000 fillets from cod caught between 1946 and 1956 in about 20 areas off the southern Canadian mainland.Geographic variation in the percentage of fillets infected was found in all size-groups of cod. For market cod the incidence ranged from a low of 6% on the offshore Nova Scotian Banks to a high of 35 to 91% in the southwestern Gulf of St. Lawrence. Intermediate values of 14% and 22% were observed respectively in the inshore fisheries of western Nova Scotia and Cape Breton Island. Similar patterns of geographic variation were present in scrod and steak cod. The main geographic differences in incidence were related to the distribution of the harbour seal (Phoca vitulina), the harp seal (Phoca groenlandica) and the gray seal (Halichoerus grypus).Incidences of infection and the number of nematodes per fillet usually varied directly with the size of the cod. The number of nematodes per pound of fillet was usually inversely related to the size of cod. It was concluded that cod could become infected throughout life and that the highest rate of infection occurred in small cod.Local variations, as distinct from broad geographic variations, were observed in the areas of Lockeport, of Cape Breton Island and of the southwestern Gulf of St. Lawrence. In these areas, the cod caught closest to shore were usually the most heavily infected.Seasonal variations in incidence occurred in the Cape Breton and Lockeport fisheries. The highest incidences occurred in the spring and fall in Cape Breton cod and in the summer in Lockeport cod. The variation in the Cape Breton fishery was attributed to seasonal migrations of the cod comprising the fishery. Increased use by fishermen of shallow inshore areas in the summer accounted for the higher summer incidences at Lockeport.Annual fluctuations in incidence were great in all areas. A ... Article in Journal/Newspaper atlantic cod Breton Island harbour seal Harp Seal Phoca groenlandica Phoca vitulina Canadian Science Publishing (via Crossref) Breton Island ENVELOPE(141.383,141.383,-66.800,-66.800) Lockeport ENVELOPE(-131.835,-131.835,52.718,52.718) Journal of the Fisheries Research Board of Canada 14 6 975 996 |
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Canadian Science Publishing (via Crossref) |
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crcansciencepubl |
language |
English |
topic |
General Medicine |
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General Medicine Scott, D. M. Martin, W. R. Variation in the Incidence of Larval Nematodes in Atlantic Cod Fillets along the Southern Canadian Mainland |
topic_facet |
General Medicine |
description |
The incidence of larval nematodes, Porrocaecum decipiens, in fillets from three size-groups (scrod, market and steak) of Atlantic cod, Gadus callarias, has been analyzed. The analysis was based on about 73,000 fillets from cod caught between 1946 and 1956 in about 20 areas off the southern Canadian mainland.Geographic variation in the percentage of fillets infected was found in all size-groups of cod. For market cod the incidence ranged from a low of 6% on the offshore Nova Scotian Banks to a high of 35 to 91% in the southwestern Gulf of St. Lawrence. Intermediate values of 14% and 22% were observed respectively in the inshore fisheries of western Nova Scotia and Cape Breton Island. Similar patterns of geographic variation were present in scrod and steak cod. The main geographic differences in incidence were related to the distribution of the harbour seal (Phoca vitulina), the harp seal (Phoca groenlandica) and the gray seal (Halichoerus grypus).Incidences of infection and the number of nematodes per fillet usually varied directly with the size of the cod. The number of nematodes per pound of fillet was usually inversely related to the size of cod. It was concluded that cod could become infected throughout life and that the highest rate of infection occurred in small cod.Local variations, as distinct from broad geographic variations, were observed in the areas of Lockeport, of Cape Breton Island and of the southwestern Gulf of St. Lawrence. In these areas, the cod caught closest to shore were usually the most heavily infected.Seasonal variations in incidence occurred in the Cape Breton and Lockeport fisheries. The highest incidences occurred in the spring and fall in Cape Breton cod and in the summer in Lockeport cod. The variation in the Cape Breton fishery was attributed to seasonal migrations of the cod comprising the fishery. Increased use by fishermen of shallow inshore areas in the summer accounted for the higher summer incidences at Lockeport.Annual fluctuations in incidence were great in all areas. A ... |
format |
Article in Journal/Newspaper |
author |
Scott, D. M. Martin, W. R. |
author_facet |
Scott, D. M. Martin, W. R. |
author_sort |
Scott, D. M. |
title |
Variation in the Incidence of Larval Nematodes in Atlantic Cod Fillets along the Southern Canadian Mainland |
title_short |
Variation in the Incidence of Larval Nematodes in Atlantic Cod Fillets along the Southern Canadian Mainland |
title_full |
Variation in the Incidence of Larval Nematodes in Atlantic Cod Fillets along the Southern Canadian Mainland |
title_fullStr |
Variation in the Incidence of Larval Nematodes in Atlantic Cod Fillets along the Southern Canadian Mainland |
title_full_unstemmed |
Variation in the Incidence of Larval Nematodes in Atlantic Cod Fillets along the Southern Canadian Mainland |
title_sort |
variation in the incidence of larval nematodes in atlantic cod fillets along the southern canadian mainland |
publisher |
Canadian Science Publishing |
publishDate |
1957 |
url |
http://dx.doi.org/10.1139/f57-043 http://www.nrcresearchpress.com/doi/pdf/10.1139/f57-043 |
long_lat |
ENVELOPE(141.383,141.383,-66.800,-66.800) ENVELOPE(-131.835,-131.835,52.718,52.718) |
geographic |
Breton Island Lockeport |
geographic_facet |
Breton Island Lockeport |
genre |
atlantic cod Breton Island harbour seal Harp Seal Phoca groenlandica Phoca vitulina |
genre_facet |
atlantic cod Breton Island harbour seal Harp Seal Phoca groenlandica Phoca vitulina |
op_source |
Journal of the Fisheries Research Board of Canada volume 14, issue 6, page 975-996 ISSN 0015-296X |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f57-043 |
container_title |
Journal of the Fisheries Research Board of Canada |
container_volume |
14 |
container_issue |
6 |
container_start_page |
975 |
op_container_end_page |
996 |
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1785578823310376960 |