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Idaho Fish & Game
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Game Fish Identification

Wednesday, May 25, 2016 

Rainbow Trout Rainbow Trout (Oncorhynchus mykiss) (native)

The rainbow trout is a very popular sport fish in Idaho. It is silver colored with black spots over its body, dorsal and caudal fins. Adult fish have a distinctive "rainbow" band along the side of their body.

Rainbow trout are native to many waters in the state. They are an easy fish to raise in a hatchery and are stocked throughout Idaho. In many cases, rainbow were stocked in both their native and new areas. Today, they are found in lakes, ponds, rivers and small streams throughout the state.

There are many varieties of rainbow trout; some of the varieties have nicknames. We usually think of rainbow trout as a beautiful, but small fish that can be caught most places, most times of the year. These rainbow live their entire life in Idaho.

Kamloop are a type of rainbow trout that was introduced into Idaho. A Kamloop lives part of its life in a lake, and part of its life in a river or small stream. In lakes, Kamloop grow rapidly and many are over 10 pounds when they are caught. A few may get to be over 30 pounds. In fact, the world record rainbow trout was a 39-pound Kamloop from Lake Pend Oreille. Steelhead are a native type of rainbow trout that are anadromous. Anadromous means they spawn in freshwater streams, go to the ocean to grow, and return to fresh water as adults. They are common to the Clearwater, Snake and Salmon rivers.

Life History
Rainbow, Kamloop and steelhead spawn in streams from mid-April to late June. They use areas of gravel, or cobble, depending on the size of the fish. The female rainbow selects a place in a riffle area below a pool to dig a redd (nest). The female displaces the gravel with her body and tail, and the male fertilizes the eggs as they are deposited. The female covers the eggs with gravel by continuing upstream and the current carries the gravel over the eggs.

The eggs hatch in early to midsummer. The young fish may live in the stream a few months, several years, or their entire life. The juvenile Kamloop and steelhead migrate to other waters, usually after two years of rearing in the stream. The juvenile fish that migrate to lakes or the ocean will grow rapidly. The growth of those that remain in the stream varies with the amount of food and temperature of stream.

When they mature and are ready to spawn, the rainbow, Kamloop, and steelhead migrate back to the place they were born. The age of sexual maturity depends on the type of rainbow and where it lives. Most rainbow require 3 to 5 years to mature.

Spawning habitat is not available in many lakes and periodic stocking is required to replenish the population.

Feeding Habits
Rainbow trout eat insects and zooplankton in the water or on the surface. They will also feed on small fish and fish eggs. As they get larger, especially the Kamloop, they will eat larger fish. Adult steelhead holding in the river prior to spawning do not eat much, but will strike at food or lures.

Angling Techniques
The rainbow is popular with Idaho anglers. They are widely distributed in accessible waters. They have a reputation for being strong fighters which makes them popular with novice and experienced anglers alike. There are as many ways to catch rainbow trout as there are fishing methods. Rainbow will take all types of bait and lures including trolling spoons, spinners, salmon eggs, corn, or even marshmallows. Many anglers use either fly casting or spinning equipment. Knowing what they commonly feed on in that specific area will help you to choose the right bait. Ice fishing for rainbows is also popular. Usually a bait of worms, maggots, or corn is suspended off the bottom.

Steelhead Trout Steelhead Trout (native)

Steelhead are a native type of rainbow trout that are anadromous. Anadromous means they spawn in freshwater streams, go to the ocean to grow, and return to fresh water as adults. They are common to the Clearwater, Snake and Salmon rivers. Excellent fishing for Idaho steelhead occurs from October through March. You will need to obtain a steelhead permit before setting out, even during a catch-and-release season.

Life History
Steelhead spawn in streams from mid-April to late June. They use areas of gravel, or cobble, depending on the size of the fish. The female selects a place in a riffle area below a pool to dig a redd (nest). She displaces the gravel with her body and tail, and the male fertilizes the eggs as they are deposited. The female covers the eggs with gravel by continuing upstream and the current carries the gravel over the eggs.

The eggs hatch in early to midsummer. The young fish live in the stream and migrate to the ocean, usually after two years of rearing in the stream. The juvenile fish that migrate to the ocean will grow rapidly.

When they mature and are ready to spawn, the steelhead migrate back to the place they were born. They enter the lower river drainages in the fall (Sept.-Oct.) and winter over to spawn the following spring, which allows a fall and spring fishing season.Most require 3 to 5 years to mature.

Feeding Habits
Steelhead trout eat insects and zooplankton in the water or on the surface. They will also feed on small fish and fish eggs. As they get larger, they will eat larger fish. Adult steelhead holding in the river prior to spawning do not eat much, but will strike at food or lures.

Angling Techniques
Steelhead respond to a variety of angling techniques. Since they are not feeding as they wait to spawn, the angler pesters the steelhead enough to get it to strike. They're aggressive and will take a variety of bait, lures, and flies. Some anglers prefer plugs, shrimp or fresh roe (fish eggs).

Yellowstone Cutthroat Trout Westslope Cutthroat Trout Cutthroat Trout - The Idaho State Fish (Onchorhynchus clarki) (native)

Cutthroat trout are named for the bright red-orange streak in the fold under the jaw. Cutthroat are native to mountain streams, lakes and rivers throughout Idaho. This is the primary reason for its designation as Idaho's state fish. They are great indicators of water quality, since they prefer very clean, pristine waters. They have been introduced into many of the high mountain lakes. Cutthroat prefer colder water than do the closely related rainbow trout.

Life History
Spawning takes place in the late spring in small tributary streams. The female digs a redd in the gravel with her tail. Cutthroat may spawn more than once and with different partners. Both the male and female are aggressive if other fish try to spawn too close to their redd. Once spawning has been completed, the female will use her body and tail to displace gravel upstream of her redd to cover it. They may spawn during the day or night. The eggs will hatch in about five weeks, early in the summer. The small cutthroat trout may live in the stream where they were born, migrate to another stream, or migrate to a lake. In many Idaho rivers, cutthroat will migrate in the fall, over-winter, and move back to their summer home. You may find yourself angling for cutthroat during only one season in order to find cutthroat large enough to catch. Like the rainbow, their size and age of sexual maturity varies. Cutthroat are usually three years old when they spawn for the first time.

Lahontan Cutthroat Trout Snake River Cutthroat Trout

Feeding Habits
Cutthroat trout will feed on aquatic and terrestrial insects. They feed along the surface, but may take insects at any level in the water. Larger cutthroat may feed on smaller fish when available.

Angling Techniques
The cutthroat trout is one of the most popular sport fish in the state. They feed aggressively, rising freely to dry flies. Fine leaders and small fly patterns are useful, but not necessary, for successful fishing. They also take nymphs, wet flies, bucktails, spinners, spoons, and natural bait such as worms or maggots. Lightweight fly and spinning setups are ideal for most streams and lakes. Heavier tackle is handy for the bigger cutthroat found in the large rivers and lakes of southeastern Idaho.

Brown Trout Brown Trout (Salmo trutta) (not native)

Brown trout are golden brown in color with large black spots, red spots with pale halos. They are the only trout with both red and black spotting. Young browns have an orange adipose fin.

Brown trout are native to Europe. They were introduced into Idaho waters in 1892. It was not until 1948 that introductions were successful. The brown trout is more tolerant of silt and warm water than native trout and, therefore, has been stocked in areas disturbed by man.

They may be found in rivers, streams, lakes, and reservoirs in the southern part of the state, particularly in the Henry's Fork River Basin. There are small populations in the Clark Fork River, Lake Pend Oreille, and other waters in the north.

Life History
Spawning occurs in October and early November. With her tail, the female digs a shallow depression in which eggs are deposited. After spawning, she covers the eggs with gravel. The eggs hatch the following April. The juvenile brown trout grow quickly for the first three years. As they reach maturity, growth slows. An adult brown might be 4 to 15 years old.

Feeding Habits
The brown trout is aggressive and territorial, chasing other species away from good cover. It feeds on many different varieties of invertebrates and small fish, both on the bottom and on the surface. Browns forage freely on the surface when mayflies, caddis flies and stone flies are emerging. They will also eat other fish.

Angling Techniques
Browns are wary and hard to catch. Bait, spoons and spinners have all proven effective in taking browns. However, for many anglers the ultimate sport is taking this species on a fly. The brown are inherently cautious, so angling with a fly requires experience to catch them consistently. They are most active at dawn and dusk; some of the larger trout are caught after dark.

Bull Trout Bull Trout (Salvelinus confluentus) (native)

The bull trout and the coastal Dolly Varden are close relatives. In fact, they are so similar that the name bull trout and Dolly Varden were used almost interchangeably until just a few years ago. Both are members of the char family. They have a green to blue-gray back, with silvery sides. No spots on the dorsal (back) fin. Yellow, orange or red spots dot its sides. The pelvic pectoral and anal fins have a white leading edge. They may weigh up to 32 pounds.

Native to Idaho, bull trout occur in most of the mountain creeks, rivers, and lakes. Although they are widely distributed, they are not abundant. They are well adapted to very cold environments, but are not very tolerant of warm water or sediment.

Life History
Bull trout spawn in October in areas with moderate stream current and good-sized gravel. The female digs a redd that may be a foot deep, and up to 3 feet by 6 feet across. Once spawning is complete, the female covers the nest by loosening gravel upstream and letting the current wash it over the nest containing the fertilized eggs. After spawning, the adults move into lakes or deeper pools to rest.

The eggs hatch in the winter and the small fish live in the gravel until early spring. The juveniles may remain in the stream or migrate to a lake. In lakes they grow rapidly and may reach 30 pounds. They are sexually mature within 4-6 years. Adult bull trout may spawn several times during their lives but may not spawn each year.

Feeding Habits
Juvenile bull trout feed on aquatic insects. As soon as they are large enough to eat fish, they do. The adults are predatory, eating primarily fish eggs of other fish.

Angling Techniques
It is illegal to harvest bull trout in Idaho. They are listed as threatened under the Endangered Species Act .

Bull trout are secretive and almost impossible to see in streams unless they are spawning. You will need to be patient to catch a glimpse.

State of Montana bull trout identification test. If anglers can effectively identify bull trout and learn about their importance, bull trout will benefit.

Lake Trout Lake Trout (Salvelinus namaycush) (not native)

Lake trout (also called Mackinaw) are the largest member of the char family in Idaho. These trout are dark gray with numerous light gray spots on the sides, both above and well below the lateral line. The tail is deeply forked. The lake trout was introduced into deep cold lakes in Idaho. Today, four Idaho lakes boast lake trout populations: Priest, Pend Oreille, Payette, and Bear.

Life History
Lake trout spawn in September in lakes, in waters 1 to 120 feet deep. They may spawn in pairs or several may spawn as a group. The eggs are quite large (1/2 inch in diameter), and are spread over boulders, or gravel. The eggs are fertilized as they fall between the rocks. Incubation may require several months; hatching has at least begun by March. The juvenile fish grow very slowly. Most of the lake trout caught are less than 10 pounds but some become large, exceeding 40 pounds. Lake trout first mature as a 6- or 7-year-old fish and may live up to 35 years.

Feeding Habits
Young lake trout feed on freshwater shrimp and other aquatic invertebrates. Larger lake trout are usually predators and eat other species of fish. In Idaho, kokanee and sculpins are often eaten by lake trout.

Angling Techniques
In early spring and fall, lake trout frequent shallow areas. When the water is fairly uniform in temperature, they can be found at all depths. As upper water temperatures increase in summer, mackinaw seek cooler, well-oxygenated levels deeper in the lakes. Lake trout prefer water temperatures of 50 degrees F. or less. As a result, the best fishing for this species is in the early spring right after ice out or in the late fall when the surface water is cold. The lake trout are a prized game fish, and may be taken be fly casting, spin or bait casting. Streamer flies, spoons, spinners and plugs are effective lures if fished close to the bottom. The most common method is trolling with large spoons. Lake trout are extremely sensitive to water temperature and some local knowledge of the area being fished is a great advantage.

Brook Trout MaleBrook Trout Female Brook Trout (Salvelinus fontinalis) (not native)

The brook trout is one of the most colorful of the trout species. The brook trout is actually a char, characterized by light spots on a dark background. The back is dark green with pale wavy lines; some people these as worm-like markings. The sides are a purple sheen with blue-haloed red spots. There are no black spots on this fish. The pelvic, pectoral and anal fins have white leading edges. Originally native to the eastern U.S. and Canada, the brook trout was introduced into Idaho waters in the early 1900's. They are now found in many of our streams and lakes.

Life History
The brook trout spawns in October and the eggs hatch in the spring. They can first spawn when they are 18 months old and only three inches long. This feature causes many brook trout populations to overcrowd their habitat resulting in individuals becoming stunted in size.

Feeding Habits
The diet of the brook trout is extremely variable as it includes invertebrates, insects, and fish. Because of this varied diet, many different fishing techniques can take brook trout.

Angling Techniques
Small spinners or spoons are often quite effective, as are both wet and dry flies. Worms also work quite well. To catch brook trout, the lure should be placed close to cover, such as submerged logs or undercut banks. Once the fish has been hooked, it is important to get it into open water as brook trout are notorious for tangling the angler's line around logs and rocks.

Kokanee Salmon Kokanee Salmon (Onchorhynchus nerka) (native)

Kokanee are a resident form of the sockeye salmon; they live in Idaho all their lives. This native fish, often called the "blueback," has greenish-blue back with faint speckling. The sides and belly are silver colored, hence another nickname, "silvers." They are usually found in large, deep lakes all over the state and in reservoirs of the southern part of the state. Individual size varies; they may be stunted 5 inch fish or a 6-pounder. Idaho kokanee are usually 10-12 inches long and weigh one-half pound to one pound.

Life History
From September through December many kokanee salmon leave their normal lake and reservoir environment for streams. Kokanee spawn upstream from the reservoir or lake. Some kokanee will remain in the lake and spawn along the shore. They dig redds, like other salmon spawning in rivers. They spawn on rocky bottoms in Idaho's larger lakes.

Their bodies become "leathery" and turn dark red to bright scarlet while their heads remain dusky green, just before spawning. As with all salmon, the kokanee die after spawning. The eggs hatch early in the spring. Soon after they swim up out of the gravel, the tiny fry migrate down the river to the lake. They usually move at night. The juvenile kokanee travel together in groups called schools of fish. They rarely live near the shore; instead they live out in the middle of the lake. These schools move around the lake in a characteristic pattern. Experienced anglers who have figured out these patterns, can be consistently successful finding kokanee.

Feeding Habits
Kokanee feed primarily on zooplankton; however, a few midges and aquatic insects are occasionally eaten. They use sieve-like structures in their mouths, called gill rakers, to strain the small plankton and invertebrates from the water. During the summer, they are deep in the lake until dusk, when they venture near the surface to feed.

Angling Techniques
Trolling or hand lining are effective methods for catching kokanee. Trolling techniques vary from trolling with small spinners, using corn on a glow hook. Hand lining is popular in the northern part of the state. It is an effective technique wherever kokanee are abundant. Anglers may use trolling techniques to find a school of kokanee. Once they locate a school they may switch to a different technique.

Coho Salmon Coho Salmon (Onchorhynchus kisutch) (native)

Coho salmon, also known as "silver salmon," are anadromous fish. That means they are born in freshwater, migrate to saltwater, and return to freshwater to spawn. Adult coho range from 8-12 pounds. They are a bright silver color in the ocean, but turn red when spawning. Upper and lower jaws become "hooked" as Coho approach spawning. Sharp teeth appear on tongue and roof of mouth. Spotting on tail fin is limited to the upper half. Coho have black mouths and white gums.

Life History
Coho spawn in October and November. Males and females die after spawning. The fry usually hatch out in March or April. Coho generally spend at least one year in fresh water before migrating to the ocean. They will generally return to their freshwater spawning grounds as three year olds, with a few waiting one more year.

Feeding Habits
Young Coho are voracious feeders focusing on plankton and aquatic insects in fresh water. Once they reach salt water they turn to a diet of fish. Adults returning to fresh water do not feed actively.

Angling Techniques
It is illegal to harvest Coho in Idaho. The Coho in the Clearwater River Drainage are the result of a reintroduction effort by the Nez Perce Tribe in cooperation with the Idaho Department of Fish and Game. To date the program has not produced enough returning adults to justify a season. Because this is a reintroduced run of fish, it is not listed under the Endangered Species Act.

Chinook Salmon Chinook Salmon (Onchorhynchus tshawytscha) (native)

This native fish is one of the most fascinating fishes found in Idaho. Its body is silver to olive-colored. The inside of its mouth is unique; it's black. They range from 18-40 inches and can attain a weight of 45 pounds.

Most of Idaho's Chinook migrate to the ocean for part of their lives. At one time, these fish were found in many of the state's river drainages. However, changes in habitat, including dam construction on the Columbia and Snake rivers, put these fish in a precarious position. The population has declined and hatchery programs are needed. Despite hatchery programs, only a few Chinook return to Idaho each year.

Fishery managers have stocked land-locked populations of Chinook in several Idaho lakes.

Life History
Chinook return to their spawning habitat in the fall after one to three years at sea. The female builds a large redd (nest) that may be six feet in diameter and one to four feet deep.

They lay between 4,500 and 10,000 eggs. When spawning is completed, both male and female die. The eggs hatch in the spring and the juvenile fish live the next year in fresh water, except for fall chinook that only live a couple months in fresh water before leaving for the ocean.

Feeding Habits
Young fish in fresh water eat both aquatic and terrestrial insects. They turn to a diet of fish once they reach salt water. Adults returning to spawn do not eat; they live off their fat reserves.

Angling Techniques
Regulations require the use of rod and reel when fishing for chinook. In streams, chinook strike bright lures or fresh roe.

In lakes, the land-locked Chinook are caught by trolling flashy lures and/or large flies on down riggers, or by jigging large lures near the bottom.

Mountain Whitefish Mountain Whitefish (Prosopium williamsoni) (native)

Mountain whitefish have large scales, no spots, and small mouths without teeth. Generally, the body is a bronze-white or greenish-white color.

Mountain whitefish are native to many of the waters of Idaho. Usually they live in rivers, moving in large groups or schools from pool to pool. Adult mountain whitefish undertake spawning migrations in the fall and feeding migrations in the spring.

These fish are more flexible in their environmental requirements than other cold-water sport fishes. They have maintained large populations in most Idaho rivers and streams. Large hydroelectric reservoirs often provide suitable habitat for these fish, and large populations are often present.

Life History
Mountain whitefish spawn in the fall over river gravel or the gravel along the lake shores. Spawning usually occurs at night during October or November. No nest is built. The eggs and milt are just deposited on the stream bottom. The eggs hatch in early to mid-March.

When they hatch the young fish are extremely small. They are almost clear. When they grow to be about 1.5 inches long, they may move away from the shallow edge of the waterway. They may live in lakes or rivers, but are rarely found in small streams. Mountain whitefish mature within 3 or 4 years and may live to be almost 20 years old.

Feeding Habits
Mountain whitefish feed primarily on bottom-dwelling aquatic insects. They also feed on terrestrial insects on the surface. It is rare, but they have been known to eat fish eggs and other smaller fish.

Angling Techniques
Mountain whitefish provide a good fight if taken on light line. Natural bait, such as worms, maggots, or the larvae of bottom-dwelling insects (such as stone fly nymphs), are usually good choices of terminal gear. They will take both wet and dry flies, but take nymphs consistently. Most anglers seek whitefish during the winter. Some whitefish are caught through the ice in lakes using a small plain baited hook.

Lake Whitefish Lake Whitefish (Coregonus clupeaformis) (not-native)

Lake whitefish have large scales, no spots, and small mouths without teeth. Generally, the body is olive green to light brown, not silvery. Their bodies are robust, not sleek. Lake whitefish are not native to Idaho. They were planted in Lake Pend Oreille and are abundant there today.

Life History
Adults congregate in the fall and early winter to spawn. They spawn well above the bottom of the lake and the eggs sink slowly. After hatching in the lake, the young whitefish continue to live deep in the lake. They travel in schools and grow rapidly.

Feeding Habits
Lake whitefish feed on zooplankton. They thrive on a particular invertebrate, the mysis shrimp, which is abundant in Lake Pend Oreille.

Angling Techniques
Summer is the preferred angling season. Most anglers use a boat to get out in the lake, and handline with bait or small jigs. Often anglers must get the lure 100 feet down to reach the fish. Fishing from a dock can be successful in the fall.

Bullhead Catfish Bullhead Catfish (Ictaluras melas, I. Nebulosus) (not native)

Both the black and brown variety of bullhead have been introduced into Idaho. They have become a popular game fish for springtime anglers using worms as bait. They are a type of catfish, but never get as big as the channel catfish. Their back is yellowish brown to almost black with an undersurface of yellow to white. It is not native to Idaho, the distribution of both the black and brown bullhead is sparse. These species require warm waters to shallow ponds, lakes, or river sloughs. The black bullhead prefers places with aquatic weeds.

Life History
In the spring, females scoop out saucer-shaped nests in mud or sand. The adhesive-type eggs are guarded by one or both parents. They fuss over the eggs, fanning the eggs with their tails and stirring them with their barbells. The fry leave the nest in a school, and the parents continue to guard them until they are about an inch long.

Feeding Habits
Food of both the black and brown bullhead is composed of snails, worms, aquatic insects, and plant material.

Angling Technique
The most popular way to fish for bullheads is by dunking a worm or cut bait. They are nocturnal feeders, so fishing is best at night. Spring is the most popular time of year to catch them.

Channel Catfish Flathead Catfish Catfish (Ictalurus punctatus) (not native)

A favorite prey for anglers with spring fever, the catfish is found in much of the Snake River. A 30-pound "cat" is a trophy fish and keeps people coming back. The back is bluish to greenish-gray with a grayish-white belly. This introduced species was first brought to Idaho in 1893 when 100 fish were planted in the Boise River.

Life History
In Idaho, catfish spawn in June and July when water temperatures exceed 75 degrees F. Dark, secluded areas under logs and rocks are preferred. The nest is prepared by the male. After the female lays the eggs, the male guards the nest until the young leave.

Feeding Habits
Catfish are omnivorous; that is, they eat plants and animals that are readily available.

Angling Techniques
Bottom fishing is best with worms, cut bait, and smelly concoctions called "stink bait."

Largemouth Bass Smallmouth Bass Bass (Micropterus salmoides, M. dolomieui)(not native)

The reputation of these fish is legendary. These introduced species grow slowly in Idaho's cold waters. Four and six pound fish are excellent fighters. The largemouth bass is dark green on the back and sides with a white belly. They can attain a size of 10 pounds. The smallmouth bass can attain 7 pounds. They have reddish eyes, a dark olive to brown back, bronze sides, and a white belly.

Populations are dispersed throughout the state. The smallmouth is not as widely distributed as the largemouth.

Bass is a very popular sport fish where they are found. There are national clubs dedicated to bass fishing. Some of these clubs have come to Idaho for competitive fishing events.

Life History
Male bass build a shallow nest when spring water temperatures reach 60 to 65 degrees F. The female will lay the eggs and then leave, or is driven off by the male. The males guard the nest until the fry (young fish) are ready to leave. Largemouth bass males will continue to guard the small school of young bass from the nest for up to a month.

Survival of the young fish through their first year is low. Largemouth can tolerate warmer water than smallmouth bass. Both species mature after about four years. They may live to spawn many times.

Feeding Habits
Bass are voracious and turn to a fish diet early in life. Frogs and crayfish are also eaten.

Angling Techniques
Anglers often fish from a boat when seeking bass, beginning the fishing trip early in the morning. Largemouth bass are night feeders and feed at the surface morning and evening near shore and usually close to cover or vegetation. Surface lures and jigs work best. Smallmouth bass can be taken on similar gear, but also on jigs fished below the surface. Look for largemouth near weeds or brushy cover. Look for smallmouth near large rocks.

Yellow Perch Yellow Perch (Perca flavescens) (not native)

Yellow perch are a greenish-yellow color down the back, with darker colored bands on their sides. The fins of this cool water species are typically orange. The first dorsal fin is spiny, and there is a very sharp edge on the gill covering. Yellow perch are small fish, averaging around seven to nine inches, but their size varies from lake to lake. "Big" perch are 12 inches long. Some lakes are known as producers of "jumbo" perch that are consistently large. Cascade Reservoir and Hayden Lake boast good perch fishing.

Perch flesh is tasty and is the preferred eating fish for many people in Idaho.

Yellow perch have been introduced to Idaho. They are found almost exclusively in lakes and reservoirs. They are rarely found in flowing water.

Life History
Spawning occurs in late April or early May. Perch prefer shallow lake areas close to reeds, cattails or fallen trees. Eggs are released during the night or early morning, and each female's eggs are fertilized by many males. Eggs are deposited in long bands of jelly-like material containing numerous eggs. These bands adhere to submerged vegetation or other underwater material, and remain there until the eggs hatch.

After hatching the young fish travel together in schools. They grow slowly in Idaho, unless they live in a warm productive reservoir. They are active all winter.

Feeding Habits
They feed on zooplankton and aquatic insects. As they get larger they may feed on other fish. They usually feed during the day. Because they are actively feeding all winter, they are great to fish for through the ice.

Angling Techniques
Many angling methods can be used to catch perch. Natural bait (worms, maggots, or eggs) often works well. Keep your hook on or near the bottom, suspended under a float. Cut bait is also used extensively. Jigging is also effective.

When ice fishing, natural bait on a bare hook has proven effective. Perch tend to be in fairly deep water (up to 40 feet) in the winter. Although perch are not known for their fighting ability, their large population and readiness to bite make them especially popular with most anglers.

Walleye Walleye (Stizostedion vitreum) (not native)

Introduced in 1974, the walleye is becoming popular with many anglers. It is greenish-yellow on the back, brassy-silver on the sides and whitish on the belly. The fairly large mouth has numerous teeth. It has a double dorsal fin, the first one being spiny, the second one having soft rays. The gill cover has a razor-sharp edge. Two other predominant characteristics are the white tip on the bottom lobe of the tail fin, and the unique glassy appearance of the large eyes. Generally, walleye average two pounds or less, but will grow up to 11+ pounds. The walleye is found in only a few reservoirs in southern Idaho.

Life History
Spawning takes place in the spring, and during the night. Most spawning occurs in lakes over boulder or gravel shoals. The males arrive first on the breeding ground, with the females arriving shortly after. The males show some pre-spawning display, primarily pursuing and circling. The female is attended by one or two smaller males. No nest is prepared: the eggs fall directly on the bottom, lodging in crevices or cracks. The eggs hatch approximately two weeks after being deposited. After hatching, growth is fairly rapid.

Feeding Habits
Walleye feed primarily at night in shallow water. During the day they move into deeper water where the light is dim. The diet of the adult walleye consists mainly of small fish and a few insects.

Angling Techniques
Jigs, spinners, spoons or natural bait all work well to catch walleye in certain situations. Remembering these basic facts will help you find success: Walleye tend to congregate in schools; when you catch one it is likely there are others in the same spot or vicinity. Except on rare occasions, walleye are found on the bottom of the lake, so the odds are with you if you keep your bait on or near the bottom. They are usually found near or on a sandbar or physical feature which provides a good feeding area in proximity to deeper waters. The primary food of walleye is fish. Your bait should resemble a bait fish in some manner and be slow moving. Walleye feed primarily in late evening, at night or in the very early morning.

Bluegill Bluegill (Lepomis macrochirus) (not native)

This introduced fish is common to lower elevation ponds in southwestern Idaho. They're great fishing for kids from 3 to 103. A three-pound bluegill caught on a fly rod or light spinning gear provides real excitement. The adult is yellowish-olive to olive-green above with bluish luster. The sides are blue with yellow bellies. The body is compressed and very short and deep.

Life History
When spring temperatures heat the water to approximately 50 degrees F, the males build saucer-shaped nests a few to 18 inches in diameter in one to five feet of water. They are fierce guardians of the nest. Females can only access the nest when they are ready to lay eggs. The male guards the young until they disperse. Bluegills generally school for life.

Feeding Habits
An avid feeder, the bluegill's diet is largely aquatic insects and invertebrates.

Angling Techniques
Bluegills bite a variety of baits, lures and artificial flies. They are excellent fighters when caught on light equipment such as a light spinning or fly fishing set-ups.

Black Crappie Black Crappie (Pomoxis nigromaculatus) (not native)

Another introduced species in Idaho is the crappie. This member of the sunfish family is olive to silvery-green with lighter sides. Black or olive flecks on the sides are randomly arranged. They rarely get over two pounds.

Life History
Crappie spawn in May and June. Like other sunfish, crappie males clear a shallow depression or nest. The female will then lay eggs which the male guards until the fry leave. The young grow rapidly.

Feeding Habits
Crappie feed on aquatic insects, crustaceans, and other aquatic insects. As they get larger, crappie feed on small fishes, especially members of the minnow family.

Angling Techniques
When fish are biting, things can get "hot." Crappie feed in schools and will take a large variety of lures and baits. Jigs and flies work well during late May to early July. They don't fight much, but are fun to fish for. Try small jigs under docks or near lily pads.

Northern Pike Northern Pike (Esox lucius) (not native)

The northern pike can be easily identified by its long slender body with light spots on a darker greenish background. The upper part of the fish is dark green, becoming lighter, almost milk-white, along the belly. A prominent feature of the pike if its very large mouth with many teeth, and the dorsal fin located far to the back of the body.

In Idaho, pike are found in the northern part of the state. They are not native. They arrived in Idaho accidentally, emigrating downstream from waters in Montana where they had been planted by agencies or stocked illegally by anglers.

Life History
Northern pike spawn in April and early May. Spawning occurs in shallow, slow waters of heavily vegetated areas in rivers, marshes, and bays of lakes. A larger female is usually attended by one or two smaller males. Only a few eggs are laid at a time so an individual fish spawns for several days. The eggs are scattered at random and adhere to the vegetation. Fertile eggs will hatch in four or five days. The young pike grow rapidly during their first summer. Juvenile fish eat aquatic insects until they are two inches long, and begin feeding on other fish.

Feeding Habits
Northern pike are a predatory fish. They feed primarily on other fish, and are known to eat frogs, mice, young muskrats and ducklings.

Angling Techniques
Morning is considered one of the better fishing periods as pike are mainly daylight feeders. Medium and shallow-running lures, jigs or large bait are generally used. Many types of artificial lures will work. Jigging a spoon or hook is also an effective way of taking pike through the ice.

White Sturgeon White Sturgeon (Acipenser transmontanus) (native)

The sturgeon is the largest of all American freshwater fish. They reside in the depths of the Snake, Kootenai, and lower Salmon Rivers. Historically, sturgeon up to 1,500 pounds were caught on set lines. Today, catch and release sturgeon fishing is allowed in the Snake and Salmon rivers. Fish up to ten-feet can be caught. Any sturgeon caught may not be removed from the water and must be released immediately. However, sturgeon fishing is not allowed in the Kootenai River as this population is listed under the Endangered Species Act.

Life History
Sturgeon spawn for the first time when they are 15-30 years old. Eggs are laid over rocky bottom in swift currents. Spawning usually takes place in May and June. It is estimated that a 350-pound female could lay 700,000 eggs. Some larger females could lay four million eggs.

Most newly hatched sturgeon die within their first year. They grow and mature very slowly. Little is known about their early life history compared to other species of fish. We know they used to migrate long distances. The fish remaining in Idaho no longer have the opportunity to migrate because of hydroelectric developments.

Feeding Habits
The sturgeon is mostly a bottom feeder and will eat almost any plant or animal matter dead or alive - with fish a large part of the diet.

Angling Techniques
Cut bait, squid, herring and shrimp are all popular baits, and are usually fished on the bottom of deep holes. Barbless hooks with a sliding sinker rig must be used.
Check out this brochure for Low impact sturgeon fishing rules and tips [PDF, 970 KB].

Last Updated: January 4, 2016 
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