Author(s): Gilbert StPierre
Information on the reproduction of Pacific halibut (Hippoglossus stenolepis) is frequently needed in management decisions. This paper reviews the literature and summarizes pertinent unpublished material collected by the International Pacific Halibut Commission (IPHC). Data on timing and locations of spawning and related migrations are given. Age and size atsexual maturity, ovary development, and duration and frequency of spawning are also discussed. Pacific halibut spawn from November to the end of March, peaking between the last week of December and the third week of January. Spawning occurs all along the coast but varies in intensity with location. It takes place near the edge of the continental shelf in depths from 100 to 550 meters but generally in waters deeper than 180 meters (100 fathoms). The average age of 50% maturity is 12 years for females and 8 years for males. The spawning period is characterized by a series of partial spawnings as the ova ripen in batches. After the first spawning, halibut are capable of spawning annually.