Satellite Telemetry in Rehabilitation and Research - Alaska SeaLife Center

PACIFIC HALIBUT

PACIFIC HALIBUT CURRENTLY BEING TRACKED:

NONE.

PACIFIC HALIBUT TAXONOMY
Kingdom:	Animalia	Anima = soul, spirit
Phylum:	Chordata	Chord = a string, musical instrument. Chordata = having a notocord or “back-string”.
Class:	Osteichthyes	Oste = bone. ichthy = fish
Order:	Pleuronectiformes	Pleur = a rib, the side. Nect = swimming. Form = shape, figure, appearance.
Family:	Pleuronectidae
Genus:	Hippoglossus	Hippos = one who drives horses. Glossa = the tongue
Species:	stenolepis	Steno = narrow, straight. Lepis = a scale.

Range	Pacific halibut are found on a variety of bottom types from the Sea of Japan to the Bering sea and to southern California. They are wide-ranging and often migratory. Young are found near shore, adults are found in deeper waters to about 3600ft (1097m).
Predators	Popular for both commercial and sport fishing. Annual catch is measured in metric tons.
Prey	They are able to eat a wide variety of fish including cod, turbot, and pollock. They will also consume invertebrates such as squid, crab and shrimp.
Size & Life Span	Halibut may live a very long time, but their growth rates vary depending on habitat conditions. Average size in commercial catch is 30 – 40 pounds. They can grow to 267 cm (105 inches) and 500 pounds. The oldest recorded female was 42 years old, the oldest recorded male, 27 years.
Reproduction	The spawning season generally takes place from November to March. During spawning season males and females congregate along the edge of the continental shelf. Males are sexually mature by 7 years and females between 8 and 12 years. Adult females lay two to three million eggs annually. After fifteen days the eggs hatch. Both eggs and larvae are free floating (pelagic) for four to six months, and may be transported hundreds of miles. During the free floating period many changes occur. The most noticeable change is the migration of the left eye to the right side of the head.
Morphology And Function	Large conical shaped teeth with two rows on top and one row on bottom. Halibut have both eyes on one side of their head. Pacific halibut are generally right eyed (eyes are located on the right side of the head). The eyed side is dark brown to black with lighter mottled spots. The blind side is creamy white in color. Lateral line system – a system that mediates sound reception in fishes, also includes the inner ear. Caudal fin – large fin that is used for propulsion. Dorsal fin – (on Pacific halibut) fin extending across the upper surface or back of the fish from the head to the caudal fin. Operculum – the gill covering in bony fishes. Cycloid scales – scales with a smooth rear edge, which makes the scales smooth to touch.
Unique Facts	Once called “hally-butte” in Middle English, meaning the flatfish to be eaten on holy days. Pacific halibut are the largest flat fish in our area. By 1932, as a result of over fishing, the Pacific halibut fishery came under regulation through the International Fisheries Commission. Today the International Pacific Halibut Commission regulates fishing for halibut.

References:

Alaska Department of Fish and Game. 1994. Wildlife Notebook Series.

Kramer, Donald E., et al. 1995. Guide to Northeast Pacific Fisheries, Families Bothidae, Cynoglossidae and,

Pleuronectidae, Marine Advisory Bulletin No. 47.

Eschmeyer, William N., Earl S. Herald. 1983. A Field Guide to Pacific Coast Fishes (North America), Houghton

Mifflin company: New York.

Hart, J.L. 1973. Pacific Fishes of Canada, Fisheries Research Board of Canada Bulletin 180.