Spawning occurs in winter and beginning of spring, where big schools are formed. Spawning sites are in offshore waters, at or near the bottom, in 50-200 m depth and 0-12 °C (preferred range 0-6°C) (Refs. 1371, 89387). May form spawning aggregations in the water column when bottom temperatures are unsuitable (Ref. 1371). Different spawning areas may be used in subsequent years (Ref. 89387). Embryo development lasts about 14 days (at 6°C) and larval phase lasts about 3 months(at 8°C). Fecundity ranges from 2.5 million eggs in a 5 kg female to a record of 9 million eggs in a 34 kg female. Reported number of batches spawned in an experiment is 8 - 22 (Ref. 5513). Sex ratio is nearly 50%, with slight predominance of females. Classified as a determinate multiple spawner (Ref. 40290). Older and larger cod had been found to produce larger eggs with neutral buoyancy at lower salinities. This can be crucial to egg and larval survival (Refs. 31930, 38384). Larvae are pelagic up to 2.5 months before settling on the bottom (Ref. 1371).
Cohen, D.M., T. Inada, T. Iwamoto and N. Scialabba 1990 FAO species catalogue. Vol. 10. Gadiform fishes of the world (Order Gadiformes). An annotated and illustrated catalogue of cods, hakes, grenadiers and other gadiform fishes known to date. FAO Fish. Synop. 125(10). Rome: FAO. 442 p. (Ref. 1371)