All About Alaska (Pacific) Halibut
The Pacific (Alaska) halibut (Hippoglos-sus stenolepis) was called “haly-butte” in Middle English, meaning the flatfish to be eaten on holy days. Because of the reproducing cycle of the halibut ,there is only one known genetic stock of halibut in the northern Pacific.
General description: Halibut are more elongated than most flatfishes, the width being about one-third the length. Small scales are imbedded in the skin. Halibut have both eyes on their dark or upper side. The color on the dark side varies but tends to assume the coloration of the ocean bottom. The underside is lighter, appearing more like the sky from below. This color adaptation allows halibut to avoid detection by both prey and predator.
Life Cycle of the Alaska Pacific Halibut
Life history: Halibut spawning takes place during the winter months with the peak of activity occurring from December through February. Most spawning takes place in deep waters of 200 to 300 fathoms. Male halibut become sexually mature at 7 or 8 years of age, and females attain sexual maturity at 8 to 12 years. Females lay two to three million eggs annually, depending on the size of the fish.Halibut are the largest of all flatfish. The largest ever recorded for an Alaska halibut was a 495-pound fish caught near Petersburg, Alaska.
Fertilized eggs hatch after about fifteen days. Free-floating eggs and larvae float for up to six months and are transported up to several hundred miles by currents of the North Pacific. During this stage, many changes take place in the young halibut, which rise to the surface and are carried to shallower waters by prevailing currents. In the shallower waters, young halibut then begin life as bottom dwellers. Most young halibut ultimately spend from five to seven years in rich, shallow nursery grounds as in the Gulf of Alaska and Cook Inlet.
Younger halibut, up to 10 years of age, are highly migratory and generally migrate in a clockwise direction east and south throughout the Gulf of Alaska. Halibut in the older age classes tend to be much less migratory. Older fish often use both shallow and deep waters over the annual cycle, however they have much smaller “home ranges” than younger, more migratory fish.Younger halibut, up to 10 years of age, are highly migratory and generally migrate in a clockwise direction east and south throughout the Gulf of Alaska.
The Pacific (Alaska) halibut (Hippoglos-sus stenolepis) was called “haly-butte” in Middle English, meaning the flatfish to be eaten on holy days. Because of the reproducing cycle of the halibut ,there is only one known genetic stock of halibut in the northern Pacific.
General description: Halibut are more elongated than most flatfishes, the width being about one-third the length. Small scales are imbedded in the skin. Halibut have both eyes on their dark or upper side. The color on the dark side varies but tends to assume the coloration of the ocean bottom. The underside is lighter, appearing more like the sky from below. This color adaptation allows halibut to avoid detection by both prey and predator.
Life Cycle of the Alaska Pacific Halibut
Life history: Halibut spawning takes place during the winter months with the peak of activity occurring from December through February. Most spawning takes place in deep waters of 200 to 300 fathoms. Male halibut become sexually mature at 7 or 8 years of age, and females attain sexual maturity at 8 to 12 years. Females lay two to three million eggs annually, depending on the size of the fish.Halibut are the largest of all flatfish. The largest ever recorded for an Alaska halibut was a 495-pound fish caught near Petersburg, Alaska.
Fertilized eggs hatch after about fifteen days. Free-floating eggs and larvae float for up to six months and are transported up to several hundred miles by currents of the North Pacific. During this stage, many changes take place in the young halibut, which rise to the surface and are carried to shallower waters by prevailing currents. In the shallower waters, young halibut then begin life as bottom dwellers. Most young halibut ultimately spend from five to seven years in rich, shallow nursery grounds as in the Gulf of Alaska and Cook Inlet.
Younger halibut, up to 10 years of age, are highly migratory and generally migrate in a clockwise direction east and south throughout the Gulf of Alaska. Halibut in the older age classes tend to be much less migratory. Older fish often use both shallow and deep waters over the annual cycle, however they have much smaller “home ranges” than younger, more migratory fish.Younger halibut, up to 10 years of age, are highly migratory and generally migrate in a clockwise direction east and south throughout the Gulf of Alaska.
No comments:
Post a Comment