Kokanee salmon

The word kokanee means "red fish" in the Sinixt Interior Salish language, and "silver trout" in the Okanagan language. ==Distribution==

Kokanee are native to many lakes in the western United States and Canada, including Alaska, Washington, Oregon, California, and Idaho in the United States and British Columbia and Yukon in Canada. Kokanee have also been introduced to lakes in southern Alberta and Saskatchewan in Canada. ==Genetic and morphological diversity==

Debate remains as to whether the kokanee has enough genetic distinction to be classified as a subspecies or a separate species from the sockeye salmon. Genetic evidence suggests that the evolution of landlocked sockeye has occurred more than once with different kokanee populations, showing genetic differences between populations. Most evidence points to events that land-locked the lake-type sockeye (which spawns in streams and lakes, rather than tributaries like the sea-type sockeye, but is still anadromous and spends most of its adult life out at sea), which evolved into the nonanadromous form. Studies done in Okanagan Lake in British Columbia and Lake Sammamish in Washington suggested that the genetic diversity between the lake-type sockeye and the kokanee marks the divergence of two species because cohabitating sockeye and kokanee did not interbreed, despite the fact that interbreeding was possible. Some morphological divergences are seen between the kokanee and sockeye. The most noticeable difference is size. The kokanee is often smaller than the sockeye due to less nutrient availability in fresh water. Other morphological differences include higher gill raker counts in the kokanee, failure to develop the changes that allow the sockeye to transition between fresh and salt water, and juvenile kokanee's lower mean swim velocity compared to juvenile sockeye. Egg sizes are also a difference. Due to its size, the kokanee should theoretically have smaller eggs to increase fecundity. In reality, the kokanee egg size varies, though the energetic cost of larger eggs can limit the fecundity of kokanee populations. Studies have found that kokanees can extract carotenoids (which provide red pigmentation during breeding) from food better than sockeyes due to sexual selection and mate choice. Again, the degree of morphological variation, such as gill raker count, can vary from population to population. The Japanese kokanee, also known as the kunimasu salmon or black kokanee, is considered a subspecies of the sockeye salmon by some, or even a separate species Oncorhynchus kawamurae, and occurs naturally in Lakes Akan and Chimikeppu in Hokkaido. The Japanese kokanee varies from its sea-going sockeye relative in a few ways. The black kokanee breeds in March at a depth of 30–40 feet, while sockeye salmon breed in the fall and have a different number of gill rakers than the kokanee. In addition, the black kokanee is much darker in color than the sockeye or any other kokanee population. The fish has been introduced to different lakes around Japan for commercial fishing practices. It seems that commercial captive-breeding programs, the introduction of non-native kokanee populations from Canada, and a population crash have decreased the genetic distinctiveness between the black kokanee and its sockeye relatives. These factors have also caused a decrease in native kokanee populations. ==Identification, lifecycle, and development==

While size range of kokanee is often lake-specific and depends on many factors, in typical populations, the kokanee grows to a typical size of with an average weight of . In bodies of water with more favorable conditions, it can reach a size up to and weigh . The largest documented kokanee, caught by hand in Lower Arrow Lake in British Columbia in 2015, weighed . Adult kokanee can be found in open water where the thermocline is around . They can have between 29 and 40 gill rakers. As fish that inhabit fresh water throughout their lifecycle, they are often smaller than their sea-going sockeye relatives, due to less food availability. The female kokanee creates a nest called a redd. She then lays around 1,000 eggs, depending on food availability. Eggs hatch within 110 days, and the juveniles swim out to the lake. the males turn bright red and develop a humped back and an elongated jaw similar to the male sockeye salmon. Females also take on a dark red hue during the breeding season, which also corresponds with the breeding season of sockeye salmon. Competition with introduced lake trout can lead to a decline in kokanee populations during the summer. Lake trout are predatory and will eat young kokanee. Predation by lake trout accounted for 83 of the 88% decline in kokanee populations in Lake Chelan, Washington. Other factors, such as pollution, habitat loss, and warming global temperatures, put the kokanee at risk in some areas. ==Conservation==

made with himemasu Some kokanee populations have declined in the US and Canada, while others thrive. The kokanee's status is variable among different locations under the Endangered Species Act. They are listed as threatened in Ozette Lake in Washington. The current IUCN red list standing of sockeye salmon (Oncohynchus nerka), which does not distinguish kokanee, is of least concern. Even so, King County, Washington, in partnership with the US Fish and Wildlife Service, has issued conservation measures to save the fish that once numbered in the thousands. As few as 150 fish spawned in 2007–2008, marking a critical need for conservation of the state's kokanee population. Currently, restoration of streams and habitats, hatchery breeding, and a ban on fishing for kokanee has caused an increase in native kokanee populations. Lakes in Canada have also seen a decline in native kokanee, with numbers dropping from 2,800 fish to just 88 fish in 2007 in the Kluane National Park and Reserve. The park has outlawed fishing of kokanee, and possession of a kokanee salmon is illegal. Conservation efforts have been largely successful, with 4,660 kokanee spawning in the park in 2015. Why the kokanee population crashed in the mid- and late 2000s is unclear. == References ==