Abstract
The reproductive behavior of Pacific cod (Gadus macrocephalus) was examined durincaptive experiments. The captive cod spawned demersal and slightly adhesive eggs, which dispersed and settled onthe tank bottom.Ripe males and females did not display the ventral mounting behavior typically displayed in other gadid fishes during spawning. Neither sound production nor aggressive behavior occurred during the breeding period. The female released approximately all of her ripe eggs in a singlespawning, which lasted less than 20 seconds. Spawning involved one female and one or more males inmidwater of the tank. Just after release of eggs by a female, one or a few males followed the female andspread sperm on the eggs using tail beats. The eggs and milt slowly sank to the bottom.
The spawning behavior of Pacific cod differed from the single-pair spawning characterized by ventral mountingand multiple spawning over a several day period seen in walleye pollock and Atlanticgadid species.
