"Oncorhynchus clarki clarki"

From marinelife1011

Contents 1 "Coastal Cutthroat Trout" (Oncorhynchus clarki clarki) 2 Description 3 Life Cycle 4 Distribution 5 Habitat and Ecology 6 References

"Coastal Cutthroat Trout" (Oncorhynchus clarki clarki)

Coastal Cutthroat Trout Oncorhynchus clarki clarki is a small relative to the larger Pacific Salmon. They are commonly referred to as Sea-Run Cutthroat, Harvest Trout, Blueback Trout or simply "Cutties".

Description

The Coastal Cutthroat's coloration, compared to its' inland relatives caters to the side of modesty. With their subdued flash and lower body fins tinted yellow and fringed with olive, and the defining mark, a yellowed slash mark on the underside of the lower gill structure. This coloration comes after spending 2 to 3 months in marine waters, making them resemble small Steelhead to the untrained eye. Spotting patterns in this anadromous species are unlike any of the other subspecies, with spots over the entirety of the body in a variety of sizes.

In the early spring many coastal streams welcome these trout home on the migration to their spawning grounds. During this process the trout loses much of its body weight to egg or milt production, giving it a long, thin, emaciated appearance, a stage in which they are commonly called "Kelts". This stage of the fishes life tends to be the most colorful, with lower body fins turning a rosy hue with white tips. The body in a faded shade of gold and brown with the slash on the underside of the gill structure turning a vibrant red. ^[1]

Life Cycle

The Coastal Cutthroat is like most of its relatives in the salmonid family, because it may spawn more than once, a reproductive strategy called Semelparity. Sexually mature adults enter streams during the fall with salmon to gorge on loose eggs and salmon flesh while building protein for reproductive organ development. The female cutthroat digs a nest or redd and the male fertilizes the eggs, going through the same courtship rituals as the relative salmon. Female cutthroat contains 200 to 4,400 eggs, which incubate and hatch in 6 to 7 weeks, emerging from their gravel nest 1 to 2 weeks after. ^[1] Young cutthroat don't act the same as salmon and rainbow trout out-migrants, instead dropping out to the marine waters in three years, though some smolts hang out for up to 7 years before leaving in the spring. Cutthroat typically spend under a year in salt water before their return migration, adults range 2 to 10 years in age, with first time spawners usually being 3 or 4 years old. Post-spawn adults are commonly called 'kelts' and are ravenous beasts rushing to put back on lost body weight before returning to salt water in late March or early April. Juveniles and adults are carnivorous, feeding mostly on insects, crustaceans, and other fish throughout their lives.

Distribution

The most widely distributed of all the western trout of North America, The coastal cutthroat trout normally does not exist more than 100 miles inland. It is known to inhabit waters as far north as Prince William Sound, AK south to the Eel River in California. Coastal cutthroat do not make lengthy migrations out to sea, and will remain in or near estuarine waters, within 5–10 mi of their natal stream. Coded wire tagging experiments have been shown that cutthroat move as far as 70 mi into the open ocean, there are also lacustrine and riverine populations mixed in with these anadromous fish that residualized in the watershed and are a vital element in the genetic diversity of each years spawning class.

Inland species range from southern Alberta, Canada, to New Mexico, and east to Colorado and Montana, and west to eastern California, all of which are non-anadromous A rare and location specific subspecies occurs in northern Baja California, Mexico and despite being a possible historical plant, it has been relocated to several locations including; the east coast of Quebec, Canada, and Europe.

Habitat and Ecology

When the trout is in the estuarine or Marine phase of life, the cutthroat utilizes tidal sloughs, bogs and marshes as holding areas and feeding grounds. These intertidal areas are crucial for the survival of the cutthroat, providing a home for small fish species, crustaceans and marine invertebrates for which to prey upon.

Large woody debris and in-stream structures play are the key structure in providing valuable habitat for coastal cutthroat trout. Adult cutthroat stake out territory in large pools while the young reside in riffles, most commonly in upper tributaries of small rivers. Cutthroat trout utilize a wide variety of habitat types during their journey, spawning in small tributary streams, and feeding in slow flowing backwater areas, low velocity pools, while the young of the year find the side channels for rearing.^[2] Healthy riparian zones, wooded uplands, in-stream woody debris, and a strong invertebrate community is necessary for a stable, sustainable population.

References

1. ↑ ^{1.0 1.1} Robert J. Behnke, Joseph R. Tomelleri (2002). Trout and Salmon of North America. New York: Simon and Schuster.
2. ↑ Orlay W. Johnson, Mary H. Ruckelshaus, et al. (1999). Status Review of Coastal Cutthroat Trout from Washington, Oregon, and California. Northwest Fisheries Science Center Coastal Zone and Estuarine Studies Division 2725 Montlake Blvd. E. Seattle WA 98112-2097

http://en.wikipedia.org/wiki/Coastal_cutthroat_trout

http://wdfw.wa.gov/fishing/salmon/cutthroat.html