TROUT Produced by Kim Tisdale Fisheries Biologist Nevada Department of Wildlife 2004
SalmonFamily • Scientific Family name is Salmonidae • Includes three subfamilies: • Salmon, Trout, and Char • Whitefish • Grayling • Economically the most important family of cold water fishes in North America • Sport Fisheries • Commercial Fishing • Hatcheries and Fish Farms
Salmon Species Pacific Salmon • Pink or Humpback • Chinook or King • Coho or Silver • Chum or Dog • Sockeye or Red Atlantic Salmon • Atlantic Salmon
Salmon Anadromous • Spends its life in the ocean but returns to fresh water to spawn • Pacific Salmon die shortly after spawning • Atlantic Salmon may live to spawn two or more times
KokaneeSalmon Landlocked Sockeye Salmon are called Kokanee Salmon. Kokanee were originally stocked into Lake Tahoe in 1950. Every fall, thousands of kokanee ascend Taylor Creek (Tahoe tributary) to spawn.
Trout and Char Photo courtesy of Mike Sevon
Trout Facts All salmonids are characterized by the presence of an adipose fin All salmonids require clean, cold water in which to live and have a low tolerance to habitat degradation. Primarily freshwater fish, however, many species develop seagoing races. • Can you name the anadromous form of the rainbow trout? Steelhead
True Trout Characteristics: Black spots on light background Stream obligate spawners Nevada’s True Trout: Cutthroat Rainbow Brown Photo courtesy of Mike Sevon
Char Characteristics: Light spots on dark background Prefer colder water than trout Spawn in the fall Can spawn in a lake environment Nevada’s Chars: Lake Trout Brook Trout Bull Trout
Can You Name the Trout Native to Nevada? Cutthroat Trout • Lahontan (Threatened species) • Bonneville • Yellowstone • Bull Trout • Threatened species • Redband Trout • Inland rainbow trout
Cutthroat Trout • Once the predominant native trout in lakes and streams across the Great Basin • Competition with non-native trout and habitat degradation can be attributed to the decline in the species • Recovery activities by NDOW and other agencies are ongoing to reestablish these fish in their historic range Official State Record Cutthroat Trout: 23 pounds 8 ounces (Pyramid Lake, 1977) Unofficial Record: 41 pounds (Pyramid Lake, 1925)
Rainbow Trout Photo courtesy of John Rupp
Rainbow Trout • The most important trout in North America based on its contribution to sport fisheries • Comprise over 90% of the hatchery production from Nevada’s four hatcheries • Rainbow are native to waters along the Pacific coast • All rainbow trout existing in Nevada are introduced with the exception of the Redband Trout which can be found in 12-mile Creek in the Northwest corner of Nevada • State Record: 16 pounds 4 ounces (Lake Mohave, 1971)
Brown Trout Photo courtesy of Mike Sevon
Brown Trout • Imported from Europe in the late 1800s and stocked throughout the United States. They were first introduced into the Truckee River in 1895. • Often described as the wariest and hardest to catch of all trout • While they prefer colder water, brown trout can tolerate temperatures as warm as 75°F and can be found in slower moving water that would be unsuitable to other trout • State Record: 27 pounds 5 ounces (Cave Lake, 1984)
Brook Trout Photo courtesy of Mike Sevon
Brook Trout • Native to the Eastern U.S. • Stocked extensively throughout the U.S. approximately 100 years ago. • Usually found inhabiting high mountain lakes and streams due to their preference for cold water (rarely found where temps exceed 65°F.) • Popular with anglers – considered the easiest trout to catch and the best tasting • State Record: 5 pounds 10 ounces (Bull Run Reservoir, 1980)
Lake Trout (Mackinaw) • Native range is the northern portion of North America from Alaska to Labrador and includes the Great Lakes • Highly prized as a sport fish due to its large size (World Record – 72 pounds 4 ounces) • Generally only found in deep, cold lakes • In Nevada, they’re found in Lake Tahoe where they have been reported at depths as deep as 1,400 feet • State Record: 37 pounds 6 ounces (Lake Tahoe, 1974)
Bull Trout • Native to the Jarbidge River system north of Elko. • The Jarbidge is a tributary to the Snake River in Idaho, however, the populations are separated by 150 miles of unsuitable trout habitat and several impassable dams. • Federally listed as Threatened • State Record: 4 pounds 6 ounces (Jarbidge River WF, 1985) • World Record: 32 pounds 0 ounces (Lake Pend Oreille, Idaho)
Spawning Spawning occurs in the spring for Rainbow and Cutthroat All other Nevada salmonids are fall spawners Female seeks out a suitable location for her nest and begins digging her redd Video footage courtesy of Manu Esteve, University of Washington
Factors Influencing Nest Location • Water Temperature • Depth • Velocity • Substrate • Cover for maturing fish • Size of Spawners (Larger fish may choose larger streams with bigger substrate) • Trout and Char often spawn in the transition area between pools and riffles where water velocity is accelerating.
Spawning Males will fight for spawning rights to the female. The most dominant male will spawn. The process of courtship and nest building will last for hours Only when the female is ready will spawning commence. Video footage courtesy of Manu Esteve, University of Washington
Spawning When the female is ready, she will signify the male by arching her back and quivering over the redd. The male will join her and they both open their mouths and release their eggs and sperm. The female immediately begins to bury the newly laid eggs. Video footage courtesy of Manu Esteve, University of Washington
Egg Development Females can lay between 200 to 8,000 eggs (depending on the size of the fish). Eggs are extremely vulnerable to predators, suffocation and fungus spores. Egg development depends entirely on water temperature Rainbow trout eggs will hatch in about three weeks at a water temperature of 54°F.
Alevin Development Newly hatched trout have a yolk sac that nourishes the young fish until it is mature enough to feed itself. Sac fry remain in the gravel until their yolk sack is absorbed.
Fry Development Once it is “buttoned-up”, the fry will work their way through the gravel to the top of the stream bed. These “swim-up” fry dart to the surface and gulp air to fill their air bladders. From this point, they are free swimming fish and begin to feed.
Juvenile Development • To reach maturity a juvenile fish must: • avoid predators, • Find adequate food • Survive summer heat and winter cold
Adult Lahontan Cutthroat Trout – Pyramid Lake Only about 2% of fertilized eggs survive to become mature adults. Most salmonids reach sexual maturity at 3 to 5 years. Some precocious fish (usually males) mature at 2 years.