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Brown trout

2007 Schools Wikipedia Selection. Related subjects: Insects, Reptiles and
Fish

            iBrown Trout and Sea Trout

                             Conservation status

   Least concern (LR/lc)
            Scientific classification

   Kingdom: Animalia
   Phylum:  Chordata
   Class:   Actinopterygii
   Order:   Salmoniformes
   Family:  Salmonidae
   Genus:   Salmo
   Species: S. trutta

                                Binomial name

   Salmo trutta
   Linnaeus, 1758

                                   Morphs

   Salmo trutta morpha trutta
   Salmo trutta morpha fario
   Salmo trutta morpha lacustris
   Fishes in the Faroe Islands:Brown trout (Salmo trutta fario)Faroese
   stamp issued: 7 Feb 1994Artist: Astrid Andreasen
   Enlarge
   Fishes in the Faroe Islands:
   Brown trout (Salmo trutta fario)
   Faroese stamp issued: 7 Feb 1994
   Artist: Astrid Andreasen

   The Brown Trout (Salmo trutta morpha fario and S. trutta morpha
   lacustris) and the Sea Trout (S. trutta morpha trutta) are fish of the
   same species distinguished chiefly by the fact that the brown trout is
   largely a freshwater fish, while the sea trout shows anadromous
   reproduction, migrating to the oceans for much of its life and
   returning to freshwater only to spawn. The lacustrine morph of brown
   trout is most usually potamodromous, migrating from lakes into rivers
   or streams to spawn, although there is some evidence of stocks which
   spawn on wind-swept shorelines of lakes. S. trutta morpha fario form
   stream-resident populations, typically in alpine streams but sometimes
   in larger rivers, as well. There is evidence that anadromous and
   non-anadromous morphs coexisting in the same river can be genetically
   identical . In common usage, the name "Brown Trout" is often applied
   indiscriminately to the various morphs.

   The brown trout is normally considered to be native to Europe and Asia
   but the natural distribution of the migratory forms may be, in fact,
   circumpolar. There are also landlocked populations far from the oceans,
   for example in Greece and Estonia. The fish is not considered to be
   endangered although, in some cases, individual stocks are under various
   degrees of stress mainly through habitat degradation, overharvest and
   artificial propagation leading to introgression. S. trutta morpha fario
   prefers cold, well- oxygenated upland waters, especially large streams
   in mountainous areas. Cover is important to trout, and they are more
   likely to be found where there are submerged rocks, undercut banks, and
   overhanging vegetation.

   The brown trout is a medium sized fish, growing to 20 kg or more in
   some localities although in many smaller rivers a mature weight of 1 kg
   (2 lb) or less is common. The current International Game Fish
   Association (IGFA) world "all tackle" record brown trout, 18.25 kg (40
   pounds, 4 ounces), was caught in May of 1992 from the Little Red River,
   Arkansas by Howard "Rip" Collins. (Story with images)

   Brown trout may live for several years although, as with the Atlantic
   salmon, there is a high proportion of death of males after spawning and
   probably fewer than 20% of female kelts recover from spawning. The
   migratory forms grow to significantly larger sizes and may live longer.
   Brown trout are active both by day and by night and are opportunistic
   feeders. While in fresh water, the diet will frequently include
   invertebrates from the streambed, small fish, frogs, and insects flying
   near the water's surface. The high dietary reliance upon insect larvae,
   pupae, nymphs and adults is what allows trout to be a favoured target
   for fly fishing. Sea trout are especially fished for at night using wet
   flies.

   The spawning behaviour of brown trout is similar to that of the closely
   related Atlantic salmon. A typical female produces about 2000 eggs per
   kilogram (900 eggs per pound) of body weight at spawning.

   Trout is a favourite food fish, and is used both fresh and smoked;
   there are many recipes for it, and it may be eaten fried, grilled,
   baked or microwaved.

   The specific epithet trutta derives from the Latin trutta, meaning,
   literally, "trout".

Stocking, farming and non-native brown trout

   The species has been widely introduced for purposes of sport into North
   America, South America, Australia and New Zealand. Brown trout have had
   serious negative impacts on upland native fish species in some of the
   countries where they have been introduced, particularly Australia.
   Because of the trout's importance as a food and game fish, it has been
   artificially propagated and stocked in many places in its range, and
   fully natural populations (uncontaminated by allopatric genomes)
   probably exist only in isolated places, for example in Corsica or in
   high alpine valleys on the European mainland.

   Farming of brown trout has included the production of infertile
   triploid fish by increasing the water temperature just after
   fertilisation of eggs, or more reliably by a process known as pressure
   shocking. Triploids are favoured by anglers because they grow faster
   and larger than diploid trout. Proponents of the stocking of triploids
   argue that, because they are infertile, they can be introduced into an
   environment that contains wild brown trout without the negative effects
   of cross-breeding. However, it is possible that stocking triploids may
   damage wild stocks in other ways. Triploids certainly compete with
   diploid fish for food, space and other resources. They could also be
   more aggressive than diploid fish and they may disturb spawning
   behaviour.

   Sea trout populations in recent years have seriously declined due to
   infestation by sea lice from salmon farms.
   Retrieved from " http://en.wikipedia.org/wiki/Brown_trout"
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   with only minor checks and changes (see www.wikipedia.org for details
   of authors and sources) and is available under the GNU Free
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