Trout
Trout is the common name given to a number of species of
freshwater fish belonging to the
salmon family,
Salmonidae.
All fish called trout are members of the subfamily Salmoninae. The name is commonly used for species in three of the seven genera in the sub-family:
Salmo, which includes
Atlantic species;
Oncorhynchus, which includes
Pacific species; and
Salvelinus, which includes fish also sometimes called char or charr. Fish referred to as trout include:
*Genus Salmo
**Adriatic trout - Salmo obtusirostris
Encyclopedia
Trout is the common name given to a number of species of
freshwater fish belonging to the
salmon family,
Salmonidae.
All fish called trout are members of the subfamily
Salmoninae. The name is commonly used for species in three of the seven genera in the sub-family:
Salmo, which includes
Atlantic species;
Oncorhynchus is a genus [i] of the family [i],
Salmonidae. ...
, which includes
Pacific species; and
Salvelinus, which includes fish also sometimes called char or charr. Fish referred to as trout include:
- Genus Salmo
- Adriatic trout - Salmo obtusirostris
- Brown trout -Salmo trutta
- Flathead trout - Salmo platycephalus
- Marmorata or Soca trout - Salmo trutta marmoratus
- Ohrid trout - Salmo letnica
- Sevan trout - Salmo ischchan
Trout are usually found in cool, clear streams and lakes, although many of the species have anadromous strains, as well. They are distributed naturally throughout
North America, northern
Asia and
Europe. Several species of trout were introduced to
Australia and
New Zealand by amateur fishing enthusiasts in the
19th century, effectively displacing several upland native fish species.
Trout have fins entirely without spines, and all of them have a small adipose fin along the back, near the tail. There are many species, and even more populations that are isolated from each other and morphologically different. However, many of these distinct populations show no significant genetic differences, and therefore what may appear to be a large number of species is considered a much smaller number of distinct species by most
ichthyologists.
The trout found in the eastern
United States are a good example of this. The brook trout, the aurora trout and the silver trout all have physical characteristics and colourations that distinguish them, yet
genetic analysis shows that they are one species,
Salvelinus fontinalis.
Lake trout , like brook trout, actually belong to the char genus. Lake trout inhabit many of the larger lakes in North America and live much longer than rainbow trout which have an average maximum life span of 7 years. Lake trout can live many decades and can grow to more than 30
kg .
Trout generally feed on soft bodied aquatic invertebrates, such as
flies, mayflies,
caddisflies,
stoneflies, and
dragonflies. In lakes, various species of
zooplankton often form large parts of the diet. In general, the larger specimens of trout prey almost exclusively on small fish, if they are available.
As a group, trout are somewhat bony, but the flesh is generally considered to be tasty. Additionally, they provide a good fight when caught with a
hook and line, and are sought after
recreationally. Because of their popularity, trout are often raised on
fish farms and planted into heavily fished waters in an effort to mask the effects of
overfishing. While they can be caught with a normal rod and
reel,
fly fishing is a distinctive method developed primarily for trout and now extended to other species. Farmed trout and char are also sold commercially as food fish.
Trout that live in different environments can have dramatically different colorations and patterns. Mostly, these colors and patterns form as
camouflage, based on the surroundings, and will change as the fish moves to different habitats. Trout in, or newly returned from the sea, can look very silvery, while the same "genetic" fish living in a small stream or in an alpine lake could have pronounced markings and more vivid coloration. It is virtually impossible to define a particular color pattern as belonging to a specific breed; however, in general, wild fish are claimed to have more vivid colors and patterns.
The cutthroat trout has 14 recognized subspecies , such as the Lahontan cutthroat trout
Oncorhynchus clarki henshawi,
Bonneville cutthroat trout Oncorhynchus clarki utah,
Colorado River cutthroat trout,
Yellowstone cutthroat trout.
See also
References
- Trout and Salmon of North America, Robert J. Behnke, Illustrated by Joseph R. Tomelleri, The Free Press, 2002, hardcover, 359 pages, ISBN 0-7432-2220-2
External links
