Reproduction and Development Most male halibut are sexually mature by about 8 years of age, while half of the females are mature by about age 12. Eggs are fertilized externally by the males. About 15 days later, the eggs hatch and the larvae drift with deep ocean currents.
Do halibut lay eggs?
Most halibut spawn during the period November through March, at depths of 300 to 1,500 feet. Female halibut release anywhere from a few thousand to several million eggs, depending on the size of the fish. Eggs are fertilized externally by the males.
How do halibut spawn?
Adults come up from relatively deep offshore water to spawn inshore at depths of 5-18 m (16-60 feet). Eggs are deposited on the substrate surface and fertilization is external. Larvae and post-larvae are pelagic for serveral months before settling on the bottom, likely in bays and estuaries.
Do halibut change gender?
When halibut reach 45 inches in length, they then change sex and become female. Mature halibut swim on their side with their dark side facing upwards. Females carry the eggs necessary for spawning, and as the eggs can reach several million in number, its the female halibut which is the larger of the two genders.
Where do halibut lay their eggs?
Pacific halibut spawn in groups in deep water at the edge of the continental shelf. They spawn by a method known as broadcast spawning, where several females and males release their eggs and sperm into the water column at the same time.
How old is a 200 lb halibut?
Halibut can reach 55 years of age, but most halibut taken in the sport fishery are 5-15 years old. Halibut age is estimated by counting growth rings laid down in the fishs otolith, a bony structure in the inner ear.