Rainbow Trout - Oncorhynchus mykiss

Fish World | Rainbow Trout - Oncorhynchus mykiss | Rainbow trout are known for their fighting qualities, making them one of the most popular sport fish freshwater in the world. Rainbow trout are from America and were introduced into New Zealand in 1883. Rainbow's average can reach 50cm (20 inches) tall and weighs about 3 kilograms (6.5 pounds). This athletic fish can easily Waterfalls 3 meters (10 feet) upstream during their spawning run clear.

The members of the family salmon, rainbow trout are salmon, living in fresh water after they hatch. They are found in Asia and most of North America. The anadromous species, those which hatch in fresh water flows back to the ocean was introduced in forty-five countries, to be used as a sport or food. These fish are known as steelhead or ocean trout. The rainbow trout is a dark olive color that becomes silvery white underneath with a prominent speckled pink body and a red stripe down the side of his body.
The rainbow trout (Oncorhynchus mykiss) is a species of salmonid native to tributaries of the Pacific Ocean in Asia and North America. The steelhead is a sea run rainbow trout (anadromous) typically return to freshwater to spawn after 2-3 years at sea. In other words, rainbow trout and steelhead trout are the same species. The fish are often called salmon trout. Several other fish in the salmonid family are called trout, some are anadromous like salmon, while others are resident only in fresh water.
The species has been introduced for food or sport at least 45 countries and all continents except Antarctica. In some locations, such as southern Europe, Australia and South America, have a negative effect on higher native species, either by eating them, outcompeting them, transmitting infectious diseases (like Whirling disease by Tubifex) or hybridization with closely related species and subspecies specific to western North America.

The species was originally named after Johann Julius Walbaum in 1792 based on type specimens from Kamchatka. Richardson named a specimen of this species Salmo gairdneri in 1836, and in 1855, WP Gibbons found a population and named it Salmo Iridia, later corrected to Salmo irideus, but these names disappeared once it was determined that Walbaum type description species was therefore had precedence (see eg Behnke, 1966). More recent DNA studies showed rainbow trout are genetically closer to Pacific salmon (Onchorhynchus species) than to brown trout (Salmo trutta) and Atlantic salmon (Salmo salar), so the family had changed.
Unlike the species 'former name of the Iridia epithet (Latin: Rainbow), the specific epithet mykiss derives from the local Kamchatkan name' mykizha, all kinds of names were based on Walbaum Kamchatkan local names.

The ocean going (anadromous) form (including those returning for spawning) are known as steelhead, (Canada and United States) or ocean trout (Australia), although the same species.

Like salmon, steelhead are anadromous: they return to their original hatching ground to spawn. Like Atlantic salmon, but unlike their Pacific Oncorhynchus kin salmonids, steelhead are iteroparous (capable of multiple, separated by one month spawn) and make some spawning trips between fresh and salt water. The steelhead smolts (immature or young fish) remain in the river for about one year before going to the sea, whereas salmon typically return to the sea as smolts. Different populations of steelhead migrate upriver at different times of the year. "Summer-run steelhead" migrate between May and October, before their reproductive organs are mature. They mature in freshwater before spawning in the spring. Most Columbia River steelhead are "summer run". "Winter-run steelhead" mature fully in the ocean before migrating, between November and April, and spawn shortly after his return. The maximum recorded lifespan for a rainbow trout is 11 years.

Rainbow trout are predators with a varied diet, and will almost eat anything they can grab. Their image as a selective eater is just a legend. Rainbows are not as piscivorous or aggressive as brown trout or lake trout (char). Young rainbows survive on insects, fish eggs, smaller fish (up to 1 / 3 of their length), along with crayfish and other crustaceans. As they grow, although the proportion of fish rising in almost all populations. Some lines are more home-planktonic feeders. While in flowing waters inhabited by salmonids, trout eat a varied diet of fish eggs, including salmon, trout killer, like the eggs of other rainbow trout, alevin, fry, young fish and even left-over carcasses.