Date post: | 26-Dec-2015 |
Category: |
Documents |
Upload: | francis-porter |
View: | 217 times |
Download: | 0 times |
TROUTTROUTProduced by Kim Tisdale
Fisheries BiologistNevada Department of Wildlife
2004
Salmon FamilyScientific 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 SpeciesPacific Salmon• Pink or Humpback• Chinook or King• Coho or Silver• Chum or Dog• Sockeye or Red
Atlantic Salmon• Atlantic Salmon
SalmonAnadromous• 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
KokaneeKokanee SalmonSalmon
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 CharTrout and Char
Photo courtesy of Mike Sevon
Trout FactsAll 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:CutthroatRainbowBrownPhoto courtesy of Mike Sevon
CharCharacteristics:
Light spots on dark background
Prefer colder water than trout
Spawn in the fall
Can spawn in a lake environment
Nevada’s Chars:Lake TroutBrook TroutBull 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
Lahontan Cutthroat TroutLahontan Cutthroat 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 TroutRainbow 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 TroutBrown 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 TroutBrook 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)Lake Trout (Mackinaw)
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 TroutBull Trout
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)
Life Cycle of Salmon and Trout
SpawningSpawning 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
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.
Females can lay between 200 to 8,000 eggs (depending on the size of the fish).
Alevin DevelopmentNewly 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.
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.
Fry Development
Juvenile DevelopmentTo reach maturity a juvenile fish must:
•avoid predators,
•Find adequate food
•Survive summer heat and winter cold
Adult
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.
Lahontan Cutthroat Trout – Pyramid Lake