Little Kern golden trout | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Salmoniformes |
Family: | Salmonidae |
Genus: | Oncorhynchus |
Species: | |
Subspecies: | O. m. whitei |
Trinomial name | |
Oncorhynchus mykiss whitei | |
Kern River trout range map |
The Little Kern golden trout (Oncorhynchus mykiss whitei) is a brightly colored subspecies of rainbow trout native to the main stem and tributaries of the Little Kern River in Tulare County, California. Together with the California golden trout (the state fish of California [3] ) and the Kern River rainbow trout, the Little Kern golden trout forms what is sometimes referred to as the "golden trout complex" of the Kern River basin. [4]
The evolutionary relationships between salmonoids is a matter of ongoing discovery, and there are different opinions about how specific populations should be grouped and named. The same can be said for the Little Kern golden trout, which has experienced several classification revisions since its first formal description.
The Little Kern golden trout was first described as Salmo Whitei in 1906 by the biologist Barton Warren Evermann in his book ...The Golden Trout of the Southern High Sierras. [5] Everman had been sent to the Kern Plateau by Theodore Roosevelt, after Roosevelt's friend Stewart Edward White had expressed concern that the brightly colored trout of the region were at risk of being fished into extinction. Everman named the fish in honor of White's role in its recognition.
In 1989, morphological and genetic studies by Gerald Smith and Ralph Stearley indicated that trouts of the Pacific basin were genetically closer to Pacific salmon ( Oncorhynchus species) than to the Salmos; brown trout (Salmo trutta) or Atlantic salmon (Salmo salar) of the Atlantic basin. [6] Furthermore, in 1992 the Little Kern golden trout was then classified as a subspecies of rainbow trout (Oncorhynchus mykiss) by Robert J. Behnke. [7] This led to the classification most commonly accepted today; Oncorhynchus mykiss whitei. [8]
The Little Kern golden trout is a brightly colored fish with profuse black spots on the back and tail. The belly and cheeks are typically a bright orange to orange-red. The lower sides of the fish range from a light yellow to bright gold. The back is olive green. The pectoral, pelvic and anal fins are orange with white tips. [9] Unlike many varieties of rainbow trout, but similar to other redband trout and trout in the "golden trout complex", the Little Kern golden trout typically retain into adulthood up to ten parr marks along their sides. There is also often an intermediate row of smaller parr marks occurring above and/or below the main row of parr marks.
Morphologically, the Little Kern golden trout sits somewhat in between the California golden trout and the typical coastal rainbow trout (Oncorhynchus mykiss irideus). Compared to the California golden trout, the brilliance of coloration in the Little Kern golden trout is usually a bit more subdued. Little Kern goldens tend to have more black spots along its back, especially anterior to the caudal peduncle, and onto its head in comparison to California golden trouts. Compared to coastal rainbow trout, Little Kern goldens tend to have fewer, larger, and rounder spots. Little Kern golden trout in their native small stream habitat rarely exceed 12 inches (30 cm) in length and any fish exceeding 10 inches (25 cm) would be considered large. [10]
Little Kern golden trout historically occupied roughly 100 miles (160 km) of the Little Kern River and its tributaries above a natural waterfall barrier preceding its confluence with the main stem Kern River. [11]
As a result of hybridization with hatchery rainbow trout introduced into its watershed, the Little Kern golden trout as a distinct subspecies experienced a widespread contraction in its range. By the 1960s it was limited to only about 8 miles (13 km) of small headwater streams above three natural barriers. [12] To address the problems of hybridization, planting of non-native trout ceased in the 1950s, and the California Department of Fish and Game (CDFG) began surveys in 1965 to initiate restoration efforts. Allozyme electrophoretic analyses begun in 1976 at UC Davis ultimately identified, what they thought were six pure populations of Little Kern Golden Trout. Restoration efforts began in 1975 with the first rotenone treatments being used to kill off non-native fish in the historic habitat. After chemical treatments there was a period of restocking of treated waters with pure Little Kern golden trout raised at the Kern River Fish Hatchery near Kernville, California from broodstock collected in the six "pure" populations previously identified. Additional restoration efforts included construction of barriers to the upstream movement of non-native trout, habitat improvement of streams damaged by cattle grazing, public education, and continued monitoring of fish populations, their genetic integrity, and habitat conditions. By 1996, restoration was believed to have been complete. [13]
Later studies showed that one of the six populations used to form the Little Kern River golden trout broodstock, clustered genetically with California golden trout and rainbow trout instead of Little Kern golden trout. [14] This study also showed that one individual fish collected as broodstock from Deadman Creek genetically clustered entirely with hatchery rainbow trout reference populations. This individual was likely inadvertently mixed with pure Little Kern Golden trout at the Kern River Fish Hatchery. The consequence of these two oversights meant that fish hybridized with rainbow trout and California golden trout were reintroduced back into Little Kern habitat.
An additional shortfall of the recovery is that the broodstock populations all came from small headwater streams with small individual populations and low genetic diversity. It is likely that the original removal of hybridized fish from the Little Kern Basin, also removed some native Little Kern golden genetic diversity that now cannot be restored. There is concern that the adaptability of the species has suffered as a result leading to an increased risk of extinction from disease or climate change. Furthermore, these populations are markedly divergent from each other; reflecting long isolation and population structure. Future work is needed to determine the extent to which divergent populations should be admixed when trying to expand the species back into its native range. [15]
Trout is a generic common name for numerous species of carnivorous freshwater ray-finned fishes belonging to the genera Oncorhynchus, Salmo and Salvelinus, all of which are members of the subfamily Salmoninae in the family Salmonidae. The word trout is also used for some similar-shaped but non-salmonid fish, such as the spotted seatrout/speckled trout.
The rainbow trout is a species of trout native to cold-water tributaries of the Pacific Ocean in North America and Asia. The steelhead is an anadromous (sea-run) form of the coastal rainbow trout(O. m. irideus) or Columbia River redband trout (O. m. gairdneri) that usually returns to freshwater to spawn after living two to three years in the ocean. Freshwater forms that have been introduced into the Great Lakes and migrate into tributaries to spawn are also called steelhead.
Steelhead, or occasionally steelhead trout, is the anadromous form of the coastal rainbow trout (Oncorhynchus mykiss irideus) or Columbia River redband trout. Steelhead are native to cold-water tributaries of the Pacific basin in Northeast Asia and North America. Like other sea-run (anadromous) trout and salmon, steelhead spawn in freshwater, smolts migrate to the ocean to forage for several years and adults return to their natal streams to spawn. Steelhead are iteroparous, although survival is only approximately 10–20%.
The cutthroat trout is a group of four fish species of the family Salmonidae native to cold-water tributaries of the Pacific Ocean, Rocky Mountains, and Great Basin in North America. As a member of the genus Oncorhynchus, it is in the Pacific trout group, which includes the widely distributed rainbow trout. Cutthroat trout are popular gamefish, especially among anglers who enjoy fly fishing. The common name "cutthroat" refers to the distinctive red coloration on the underside of the lower jaw. The specific name clarkii was given to honor explorer William Clark, coleader of the Lewis and Clark Expedition.
The Californiagolden trout (Oncorhynchus aguabonita or Oncorhynchus mykiss aguabonita) is a species of trout native to California. The golden trout is normally found in the Golden Trout Creek, Volcano Creek, and the South Fork Kern River. The Golden trout is the official freshwater state fish of California since 1947.
Oncorhynchus is a genus of ray-finned fish in the subfamily Salmoninae of the family Salmonidae, native to coldwater tributaries of the North Pacific basin. The genus contains twelve extant species, namely six species of Pacific salmon and six species of Pacific trout, all of which are migratory mid-level predatory fish that display natal homing and semelparity.
Lahontan cutthroat trout is the largest subspecies of cutthroat trout and the state fish of Nevada. It is one of three subspecies of cutthroat trout that are listed as federally threatened.
Redband trout are a group of three recognized subspecies of rainbow trout. They occur in three distinct regions in Pacific basin tributaries and endorheic basins in the western United States. The three subspecies are the Columbia River redband trout, the McCloud River redband trout and the Great Basin redband trout.
The westslope cutthroat trout, also known as the black-spotted trout, common cutthroat trout and red-throated trout is a subspecies of the cutthroat trout and is a freshwater fish in the salmon family of order Salmoniformes. The cutthroat is the Montana state fish. This subspecies is a species of concern in its Montana and British Columbia ranges and is considered threatened in its native range in Alberta.
San Leandro Creek is a 21.7-mile-long (34.9 km) year-round natural stream in the hills above Oakland in Alameda County and Contra Costa County of the East Bay in northern California.
The coastal cutthroat trout, also known as the sea-run cutthroat trout, blue-back trout or harvest trout, is one of the four species of cutthroat trout found in Western North America. The coastal cutthroat trout occurs in four distinct forms. A semi-anadromous or sea-run form is the most well known. Freshwater forms occur in both large and small rivers and streams and lake environments. The native range of the coastal cutthroat trout extends south from the southern coastline of the Kenai Peninsula in Alaska to the Eel River in Northern California. Coastal cutthroat trout are resident in tributary streams and rivers of the Pacific basin and are rarely found more than 100 miles (160 km) from the ocean.
The Mexican golden trout is a species of fish in the family Salmonidae. The species is endemic to high-elevation headwaters of the Fuerte River, Sinaloa River, and Culiacán River drainages in the Sierra Madre Occidental in Mexico.
The Golden Trout Wilderness is a federally designated wilderness area in the Sierra Nevada, in Tulare County and Inyo County, California. It is located 40 miles (64 km) east of Porterville within Inyo National Forest and Sequoia National Forest.
The cutbow is an interspecific fertile hybrid between rainbow trout and cutthroat trout. While natural separation of spawning habitat limited hybridization in most native populations of rainbow and cutthroat trout, introduction of non-native hatchery-raised rainbow trout into native cutthroat trout range increased hybridization across the landscape. Due to these introductions, many populations of cutthroat trout are at risk of genetic pollution. As a result, significant management intervention at state and federal levels has occurred to preserve native populations of cutthroat trout.
The Baja California rainbow trout or San Pedro Martir trout or Nelson's trout is a localized subspecies of the rainbow trout, a freshwater fish in the family Salmonidae.
The McCloud River redband trout is one of three redband trout subspecies of the rainbow trout in the family Salmonidae. The trout is native in small tributaries of the McCloud River and Pit River which are tributaries of California's Sacramento River. Its historic range has declined significantly since it was first described in 1894. Remaining populations of genetically pure McCloud River redband trout are threatened by predation, habitat loss, competition with introduced trout species and by hybridization with hatchery rainbow trout introduced to support sport fishing.
The Sheepheaven Creek redband trout is a local Californian variety of the rainbow trout, a freshwater fish in the family Salmonidae. It is considered either a distinct western form of the McCloud River redband trout, or a subspecies of its own, which has not been scientifically named and described yet. It is native to Sheepheaven Creek, Siskiyou County, California, United States. It has been transplanted into Swamp Creek in 1972 and 1974 and into Trout Creek in 1977. They can now be found in both locations. Sheepheaven Creek redband are found to be the most distinct anatomically among all other western North American trout groups, and therefore has been suggested to merit recognition as a new subspecies. A key diagnostic character is that they have the fewest gill rakers of any western trout.
The Kern River rainbow trout is a localized subspecies of the rainbow trout, a variety of fish in the family Salmonidae. It is found in a short section of the main stem of the Kern River and several tributaries in the southern Sierra Nevada in California. The Kern River rainbow trout is a "Species of Special Concern" in the state of California due to habitat loss and hybridization with other native and non-native trout in their range.
Mexican native trout —Mexican rainbow trout, sometimes Baja rainbow trout and Mexican golden trout —occur in the Pacific Ocean tributaries of the Baja California peninsula and in the Sierra Madre Occidental of northwestern Mexico as far south as Victoria de Durango in the state of Durango. Many forms of the Mexican rainbow trout, subspecies of the rainbow trout, have been described. The Mexican golden trout is a recognized species.
The Athabasca rainbow trout is a population of rainbow trout, a fish in the family Salmonidae.