Blood Protozoa as an Aid for Separating Stocks of Greenland Halibut, Reinhardtius hippoglossoides, in the Northwestern Atlantic

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Authors: Khan, R. A., Dawe, M., Bowering, R., Misra, R. K.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1982
• Subjects: Greenland; Davis Strait; Newfoundland; Northwest Atlantic
• Online Access: http://dx.doi.org/10.1139/f82-176; http://www.nrcresearchpress.com/doi/pdf/10.1139/f82-176

Samples of subadult Greenland halibut, Reinhardtius hippoglossoides, from several northwest Atlantic locations, the Gulf of St. Lawrence, and Fortune Bay, an inlet on the south coast of Newfoundland, were examined for the prevalence of two blood protozoa. Because prevalence of infection varied widely, the data were analyzed using the general least squares analysis of fitting constants on logit values. Trypanosome and piroplasm infections in samples from Davis Strait, NAFO divisions 2G–2H and div. 3L, were mostly similar, but differed significantly from div. 2J–3K. Trypanosome infections in samples from the northwest Atlantic locations were significantly higher than in the Gulf of St. Lawrence and Fortune Bay. Piroplasm infections were significantly higher in samples from Fortune Bay than in the Gulf of St. Lawrence. The results suggest that Greenland halibut from Davis Strait, div. 2G–2H and div. 3L, are composed of one stock complex, while fish from div. 2J–3K represent an isolated group or most probably a cline between areas. Greenland halibut from the Gulf of St. Lawrence and Fortune Bay appear to represent distinct stocks.Key words: blood protozoa, trypanosome, piroplasm, Greenland halibut, stock separation, northwestern Atlantic