Gourt > Science > Biology > Ecology > Aquatic Ecology > Fisheries Science > Anadromous and Stream Fish
A fish is a water-dwelling vertebrate with gills. Most are cold-blooded. There are over 29,000 species of fish, making them the most diverse group of vertebrates. Taxonomically, fish are a paraphyletic group whose exact relationships are much debated; a common division is into the jawless fish (class Agnatha, 75 species including lampreys and hagfish), the cartilaginous fish (class Chondrichthyes, 800 species including sharks and rays), with the remainder classed as bony fish (class Osteichthyes).
Fish come in different sizes, from the 16 m (51 ft) whale shark to a 8 mm (just over ¼ of an inch) long stout infantfish. Many types of aquatic animals named "fish", such as jellyfish and cuttlefish, are not true fish. Other sea dwelling creatures, like dolphins, while closely resembling fish in outer appearance, are actually mammals.
Although most fish are exclusively aquatic and cold-blooded, there are exceptions to both cases. Fish from a number of different groups have evolved the capacity to live out of the water for extended periods of time. Of these amphibious fish some such as the mudskipper can live and move about on land for up to several days. Also, certain species of fish maintain elevated body temperatures to varying degrees. Endothermic teleosts (bony fishes) are all in the suborder Scombroidei and include the billfishes, tunas, and one species of "primitive" mackerel (Gasterochisma melampus). All sharks in the family Lamnidae – shortfin mako, long fin mako, white, porbeagle, and salmon shark – are known to have the capacity for endothermy, and evidence suggests the trait exists in family Alopiidae (thresher sharks). The degree of endothermy varies from the billfish, which warm only their eyes and brain, to bluefin tuna and porbeagle sharks who maintain body temperatures elevated in excess of 20 °C above ambient water temperatures. See also gigantothermy. Endothermy, though metabolically costly, is thought to provide advantages such as increased contractile force of muscles, higher rates of central nervous system processing, and higher rates of digestion.
More on [ Fish ]
River Restoration :: Fishing
Bony :: Fish
Ichthyology :: Chordates
Rivers and Streams :: Water Resources
Hydro :: Renewable
Information Archive: DRIIA - Information on dams, water diversions, impoundments, and hydroelectric projects, their impacts, and related links.
Central New England Anadromous Fish Program - Restoring salmon and other anadromous fish to the Merrimack River and other watersheds. (U.S. Fish and Wildlife Service)
Meta Description: [ Central New England Complex activities involve the development of partnerships to restore and manage interjurisdictional fishes and aquatic resources. ]
Columbia Basin Research - Efforts at the University of Washington to investigate issues surrounding salmon biology in the Columbia and Snake River basins. CBR research has produced computer models which simulate and predict salmon migration and survival in the Columbia Basin and salmon harvest in the North Pacific.
Meta Description: [ Columbia Basin Research, CBR, is a joint effort of scientific research projects through the School of Aquatic and Fishery Sciences at the University of Washington investigating issues surrounding salmon biology in the Columbia and Snake River basins. ]
Daily Fish Passage Report - Current data on fish passing dams in the Columbia River system, northwestern U.S. Fish counts for Lower Granite begin March 1st. Counts for Bonneville begin March 15th. All others begin April 1st.
Fish Passage Center - Current and historic data on salmon and steelhead in the Snake and Columbia river basins.
Meta Description: [ The Fish Passage Center (FPC) provides current
and historic data on salmon and steelhead passage in the main stem Snake and
Columbia river basins. Data from the Smolt Monitoring Program (SMP) is intended
to provide the information basis for federal, state and tribal recommendations
for fish p... ]
FishXing Software and Learning Systems for Fish Passage Through Culverts - US Fish and Wildlife Service computer tools to assist in design and evaluation of culverts for fish passage. FAQ, downloads, bibliography of related technical papers, and other resources on the topic.
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Individual-Based Fish Modeling at Humboldt State University - Modeling software, theory, and applications. Instream flow model for trout. Salmon out-migration survival simulator.
King County Salmon and Trout Topics - Online information about salmon and trout in King County and the Puget Sound region, including news, conservation and monitoring efforts, and conservation volunteer opportunities.
Meta Description: [ Info about salmon and trout in the Seattle-King County area, including news, conservation and monitoring efforts, fish ecology info, and volunteer opportunities. ]
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Lost at Sea: What's Killing the Great Atlantic Salmon? - Smithsonian Magazine article about threats to the population of this fish.
Meta Description: [ Articles from the Smithsonian Institution's award-winning, monthly general interest magazine, plus exclusive Web articles, videos, blogs, photographs and more. ]
Max Ledbetter - Competition and information among British Columbia salmon purse seiners: spatial analysis, past exploitation rates, comments.
Meta Description: [ COMPETITION AND INFORMATION AMONG BRITISH COLUMBIA SALMON PURSE SEINERS ]
Pacific Salmon Recovery: A Sampling of Viewpoints - Review (with large collection of web links) of scientific, political, religious, and other views about Pacific salmon recovery for the Oregon Coast and Columbia River Basin; including views about dams, hatcheries, habitat, and fisheries.
Meta Description: [ Viewpoints about Pacific salmon and steelhead recovery for the Oregon Coast and Columbia River Basin. ]
Passive Integrated Transponder Information System - The Passive Integrated Transponder (PIT) tag has been developed as a research and management tool for monitoring the movement of juvenile and adult salmonids in the Columbia River Basin.
Meta Description: [ PIT (Passive Integrated Transponder) tags are used to monitor the movement and inferred behavior of juvenile and adult salmon and steelhead trout throughout the Columbia River Basin in the Pacific Northwest region of the United States. The PIT Tag
Information System (PTAGIS) provides a centralize... ]
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Razorback Sucker and Colorado Squawfish Parasites-Disease - Short report on an experimental study to determine the cause of the poor success of fish re-introductions in the Gila River.
Seymour River Fish Hatchery and Education Centre - Raising Salmon and trout for sustaining stocks in the Seymour River, British Columbia. An educational facility for teaching people the importance of fish, habitat and environment.
Meta Description: [ Seymour Salmonid Society runs the Seymour River Fish Hatchery and Education Centre. It holds educational classes on conservation, fish life cycle and create much needed fish habitat ]
The Salmon Are Calling - Essay about the decline of wild salmon populations.
Meta Description: [ The great wild fish that have filled our plates and our souls are dying. By learning to save them, we may save ourselves. ]
The Whirling Disease Foundation. - Information on the progress of whirling disease research. Whirling disease, caused by the microscopic parasite Myxobolus cerebralis, has severely damaged wild trout populations in some western U.S. fishing streams.
Meta Description: [ The Whirling Disease Foundation provides information on the progress of whirling disease research. The foundation raises money for the scientific research of whirling disease. ]
Washington Trout - Nonprofit science-based organization working to protect and restore Washington State's wild fish (including salmon) and their habitats. Site describes current stream survey and restoration projects.
Meta Description: [ Washington Trout: Protect, Preserve, Restore ]
Watershed Watch Salmon Society - Registered non-profit whose purpose is to conduct research, and educate the public about wild salmon and issues surrounding them. Information about fisheries and habitat management topics, particularly in Canada.
Meta Description: [ Information on water use planning, local water issues, salmon conservation, the dangers of salmon farming and other freshwater and marine issues ]
West Galloway Fisheries Trust - Manage Salmon fisheries in Scotland.
Meta Description: [ Galloway Fisheries Trust are a fisheries trust based in Scotland. ]
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Whirling Disease Initiative - U.S. National Partnership on the Management of Wild and Native Cold Water Fisheries research and information on this trout infection caused by a parasite (Myxobolus cerebralis) with a two-host life cycle -- fish and worms.
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