TROUTTROUTMrs. Garbiel: Oceanography & Environmental
Science
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 SpeciesSalmon SpeciesPacific SalmonPacific Salmon• Pink or HumpbackPink or Humpback• Chinook or KingChinook or King• Coho or SilverCoho or Silver• Chum or DogChum or Dog• Sockeye or RedSockeye or Red
Atlantic Salmon• Atlantic Salmon
SalmonAnadromousAnadromous• Spends its life in the ocean but returns Spends its life in the ocean but returns
to fresh water to spawnto fresh water to spawn
• Pacific SalmonPacific Salmon die shortly after die shortly after spawningspawning
• 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 TroutTrue TroutCharacteristics:Characteristics:
Black spots on light Black spots on light backgroundbackground
Stream obligate spawners
Nevada’s True Trout:Cutthroat
– Lahontan (Threatened species)
– Bonneville– Yellowstone
Rainbow*Brown
Photo 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
Lahontan Cutthroat TroutLahontan Cutthroat Trout
Cutthroat TroutCutthroat 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
When the female is ready, she will signify the male by arching her back and quivering over the redd (gravel nest) she has built with her tail.
The male fertilizes them by covering them with a milky substance known as milt.
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).
Salmon are born in gravel beds in streams 10 to 700 miles (16 to 1200 km) from the sea. Laid in the fall, the eggs incubate over the winter, frequently under several feet (more than a metre) of snow and ice. Their pink eggs are always covered from direct sunlight. About a month after they have been deposited in the gravel, eyes begin to show. This normally happens in late November or early December. It is essential during this time that water flow and temperature are suitable. The period of greatest mortality in the salmon's life cycle is in the egg-to-fry stage.
TROUT IN THE CLASSROOM
When When will will they they hatchatch?h?
TROUT IN THE CLASSROOMWater Temperature
35 °F 40 °F 45 °F 50 °F 55 °F
Rainbow Trout
Days to hatch - 80 48 31 24
DTU’s - 640 624 558 552
Brown Trout
Days to hatch 156 100 64 41 -
DTU’s 468 800 832 738 -
Hatch between Feb. 12-14th.
TROUT IN THE CLASSROOM
FACTORS EFFECTING EGG DEVELOPMENT
LIGHT
-Direct sunlight or UV light will effect the development of the eggs.
30 minutes of light will kill them
-The optimal thing to do is minimize there light exposure.
TROUT IN THE CLASSROOM
TEMPERATURE
-Fluctuation for developing eggs is a good thing within range.
2°F to 3°F is an optimal temperature variation.
Cutthroat Trout Eggs
• Eyed eggs• 22 days old• @ 47 DegreesF• Our eggs were fertilized on
Jan. 13. 2009
Alevin (sac fry) Development
Stay in gravelStay in gravel
1-6 wks after hatching1-6 wks after hatching
The embryo produces an The embryo produces an enzyme which dissolves the enzyme which dissolves the egg shell (a white foam on the egg shell (a white foam on the surface at hatching time). surface at hatching time).
Eggshells need to be removed Eggshells need to be removed to prevent fungusto prevent fungus
Change half the water and use Change half the water and use the baster to remove shells.the baster to remove shells.
Alevin (sac fry) Development
Newly hatched trout Newly hatched trout have a yolk sac that have a yolk sac that nourishes the young nourishes the young fish until it is mature fish until it is mature enough to feed enough to feed itself. itself.
Sac fry remain in the Sac fry remain in the gravel until their gravel until their yolk sack is yolk sack is absorbed.absorbed.
The vitelline vein, running through the centre of the sac, picks up oxygen from the water.
Cutthroat Trout Alevin(sac fry)
They will remain in the gravel and avoid light. Keep in darkness.
– Sac Fry– 35 days old– @ 47 degrees F
Cutthroat Trout Sac Fry
– Sac Fry in late development
– 44days– @ 47 Degrees F
Cutthroat Trout Fry
• Fry• 55 days• @ 47 Degrees F
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
2-5 “
Most hatchery trout are stocked into lakes at this size
Develops “finger” markings
At about 6” in length called Parr
Fingerlings/Parr
SmoltAt this point, the juvenile salmon loses its vertical markings on its body and turns silvery in color. Now considered Smolt, they will school together in large groups. It's at this time that the young salmon will adjust their bodies to saltwater, allowing them to swim out into the Pacific Ocean to feed and grow into adult salmon.
Juvenile DevelopmentTo reach maturity a juvenile fish must:
•avoid predators,
•Find adequate food
•Survive summer heat and winter cold
•Release 5-7 days after “button up”…
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
