Studies of Reproduction and Feeding of Atlantic Cod ( Gadus callarias L.) in the Southwestern Gulf of St. Lawrence

• Published in: Journal of the Fisheries Research Board of Canada
• Main Author: Powles, P. M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1958
• Subjects: General Medicine; atlantic cod
• Online Access: http://dx.doi.org/10.1139/f58-076; http://www.nrcresearchpress.com/doi/pdf/10.1139/f58-076

Size at maturity, time of spawning, fecundity and food of cod were examined in the southwestern Gulf of St. Lawrence during the summers of 1955 and 1956. In 1955 and 1956 males were 50% mature at 50 and 53 cm., respectively; females, for the same years, were 50% mature at 52 and 57 cm., respectively. The spawning period lasted from May to September, with peak spawning at the end of June. A cod of 51 cm. in length produced 200,000 eggs, while a larger specimen of 140 cm. in length carried 12 million ripening eggs.Small cod, of 11 to 30 cm. in length, selected a diet of pelagic crustaceans, namely mysids, euphausids and amphipods. With increase in size, cod adopted a more varied diet, in which fish and benthic invertebrates became increasingly important. At lengths over 70 cm., pelagic and bottom forms were taken in approximately equal volumes. Herring was the most important fish in the diet of large cod over 50 cm. in length.