List of fishes of Colorado facts for kids

The location of the State of Colorado in the United States of America.

Colorado is a state in the United States that is home to many different kinds of fish. There are 101 types of fish living here. About 55 of these fish are naturally found in Colorado, meaning they are native species. Sadly, 23 of these native fish are in danger. This means their populations are very low. Some of the fish that are most at risk include the Humpback Chub, Bonytail, Colorado Pikeminnow, and Razorback Sucker.

Amazing Fish of Colorado
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Amazing Fish of Colorado

Colorado's waters are filled with a wide variety of fish, each with unique features and habits. Let's explore some of these fascinating creatures, from tiny minnows to large catfish!

Suckers: Bottom Feeders with a Purpose

Suckers are a group of fish that often feed on the bottom of rivers and lakes. They play an important role in keeping our waters clean.

American Eel

The American eel (Anguilla rostrata) is not native to southern Colorado. It usually lives on the East Coast in freshwater rivers. Female eels can grow up to 5 feet long, while males are usually about 2 feet long. These eels are very good at adapting to different places. They can travel from freshwater rivers all the way to the ocean to lay their eggs!

River Carpsucker

The River carpsucker (Carpiodes carpio) is native to eastern Colorado. These fish like large, deep rivers with sandy or silty bottoms where the water moves slowly. They can also be found in smaller creeks. River carpsuckers are not in danger. They usually grow to be 12 to 18 inches long and weigh 1 to 3 pounds. They live for about 2 to 4 years.

Quillback

The Quillback (Carpiodes cyprinus) has been seen in southeastern Colorado. These fish live in warm rivers and lakes. They prefer clear, slow-moving, shallow waters. Quillbacks eat both plants and small animals, like insects, tiny water creatures, leaves, and algae. They can live for a long time, up to 11 years, and grow to about 15 to 20 inches long.

Longnose Sucker

The Longnose sucker (Catostomus catostomus) is native to the eastern slopes of Colorado. They live in clear lakes and streams, preferring water that moves at a moderate to fast speed. These suckers can grow to 15 to 20 inches long and weigh 1 to 2 pounds. They are bottom feeders, slowly searching for small water creatures, algae, and fish eggs to eat.

White Sucker

The White sucker (Catostomus commersoni) is native to eastern Colorado. It was later brought to the western slopes. You can find white suckers in cool, clear rivers, streams, and lakes. They usually eat aquatic plants, algae, and small water creatures. White suckers can reach about 20 inches long and weigh 2-3 pounds. They often live for about 15 years.

Bluehead Sucker

The Bluehead sucker (Catostomus discobolus) is native to the western slopes of Colorado. These fish are found in streams and large rivers. They need water that moves at a medium to fast speed, so you won't find them in lakes. Bluehead suckers like rocky riverbeds. They feed on algae, small water creatures, and bits scraped from rocks.

Flannelmouth Sucker

The Flannelmouth sucker (Catostomus latipinnis) is native to Colorado. It lives in large streams and rivers with cloudy water and sandy or muddy bottoms. As a bottom feeder, the flannelmouth sucker eats algae and small water creatures like insect larvae. These fish can grow up to 28 inches long and live for up to 30 years!

Mountain Sucker

The Mountain sucker (Catostomus platyrhynchus) is native to northwestern Colorado. They live in smaller rivers and streams with gravel, sand, and mud bottoms. You can also find them in calm spots (eddies) and small pools with a medium current. Younger suckers stay in shallower, calmer areas. Mountain suckers eat algae, insects, and larvae.

Rio Grande Sucker

The Rio Grande sucker (Catostomus plebeius) is native to southern Colorado. These fish live in rocky pools, fast-moving sections of rivers, and small to medium-sized rivers. They prefer fast-flowing water for cover. They generally feed on algae and small water creatures.

Smallmouth Buffalo

The Smallmouth buffalo (Ictiobus bubalus) is not native to Colorado. These fish can be found in rivers and lakes. They prefer clean or slightly cloudy, warm, and deep waters with lots of plants. Smallmouth buffalo eat shellfish, algae, insects, and other creatures found on the bottom. They can grow up to 36 inches long and weigh between 2 and 10 pounds.

Shorthead Redhorse

The Shorthead redhorse (Moxostoma macrolepidotum) is not native to Colorado. These fish usually live in lakes, often in shallower areas with sand and gravel. They prefer clean, clear water. Their diet includes small snails, insects, insect larvae, and other small water creatures. Shorthead redhorse fish usually grow to 12 to 18 inches long and weigh about two to three pounds. Some can reach 25 inches.

Razorback Sucker

The Razorback sucker (Xyrauchen texanus) is native to western Colorado. This is a large native sucker that can grow up to 20 inches long and weigh 2-3 pounds. Adults live in deeper waters, from 4–10 feet, where currents are strong. They feed on algae and small water creatures. This species is critically endangered.

Sunfish and Bass: Popular Game Fish

This group includes many fish that are popular for fishing, known for their feisty nature.

Sacramento Perch

The Sacramento perch (Archoplites interruptus) is not native to Colorado. They live in calm waters like ponds and slow-moving rivers. They can adapt to clear waters with plants or cloudy waters with rocky bottoms. Sacramento perch eat insects, insect larvae, small water creatures, and small fish. They are typically about 12 inches long and weigh about three-quarters of a pound. This species is endangered.

Rock Bass

The Rock bass (Ambloplites rupestris) is not native to Colorado. They live in clear streams, rivers, and lakes. They like places with cover, such as rock piles, large boulders, and tree roots, often found along the shoreline. Rock bass mainly eat aquatic insects, crayfish, and minnows. They usually grow to 7 to 10 inches.

Green Sunfish

The Green sunfish (Lepomis cyanellus) is native to Colorado and found in small lakes and ponds. This common fish can sometimes over-populate lakes. Green sunfish will eat almost anything that fits in their mouths, like insects, small fish, small crayfish, and frogs. They live in many different environments. Their typical length is between three and six inches.

Pumpkinseed

The Pumpkinseed (Lepomis gibbosus) is not native to Colorado. This sunfish usually lives in lakes and ponds with lots of plants. They prefer shallow waters near cover like weeds, docks, and sunken plants. Pumpkinseeds are typically six to eight inches long and can live up to eight years. They eat insects, insect larvae, small water creatures, and small fish.

Warmouth

The Warmouth (Lepomis gulosus) is native to Colorado. Warmouth live in lakes, ponds, swamps, and slow-moving streams. They prefer muddy or plant-filled bottoms and hide in rocky banks or near tree stumps. Warmouth hunt by sight, eating crayfish, insects, and small fish. A typical warmouth is 4 to 10 inches long.

Orangespotted Sunfish

The Orangespotted sunfish (Lepomis humilis) is native to northern Colorado. Like green sunfish, they stay close to cover like rocks, stumps, and weeds. You can find them in slow-moving and cloudy waters, especially in large muddy rivers and reservoirs. Orangespotted sunfish eat insects, crayfish, larvae, and small fish. These fish typically grow to 2-3 inches long.

Bluegill

The Bluegill (Lepomis macrochirus) is native to Colorado. Bluegill like to live in weed beds and deep areas of lakes and ponds. They also live in slow-moving streams and lagoons. They usually stay near brush piles and under overhanging trees for shade. Bluegill eat insects, larvae, worms, crayfish, and small fish. A common bluegill is about 7.5 inches long and lives for four to six years, though some can live up to 11 years.

Smallmouth Bass

The Smallmouth bass (Micropterus dolomieu) is not native to Colorado. Smallmouth bass prefer large, clear lakes and reservoirs, but can also be found in clear streams. They like gravelly or rocky bottoms and structures like logs, trees, rocks, and dam faces. Their main diet is small fish, crayfish, and insects. A typical smallmouth bass is 8 to 12 inches long. They can live up to 12 years and become adults by three to four years old.

Largemouth Bass

The Largemouth bass (Micropterus salmoides) is not native to Colorado. Largemouth bass live in shallow areas with lots of plants like reeds and water lilies. They prefer calm, clear lakes and ponds. Bass eat minnows, carp, trout, crayfish, and any other fish available, even their own kind. A typical bass is about 15 inches long and weighs one to two pounds.

White Crappie

The White crappie (Promoxis annularis) is not native to Colorado. White crappies usually live in reservoirs and freshwater lakes, but also in ponds and slow-moving rivers with sandy or muddy bottoms. They don't mind if the water is cloudy or clear. White crappies typically grow to 6 to 20 inches long and weigh 1 to 5 pounds. Young crappies eat tiny water creatures, while adults mainly eat minnows and small shad.

Black Crappie

The Black crappie (Pomoxis nigromaculatus) is not native to Colorado. Black crappies live in lakes, reservoirs, rivers, streams, and calm backwaters. They are usually found in clear water with plants around them and mud or sandy bottoms. Black crappies can grow up to 19.3 inches long, but are typically 10.8 inches. Young black crappies eat tiny water creatures and insect larvae. Adults mainly eat small fish.

Herring and Shad: Schooling Fish

This family includes fish that often swim in large groups.

Gizzard Shad

The Gizzard shad (Dorosoma cepedianum) is native to Colorado. Gizzard shad are found in large rivers, lakes, and swamps. They can live in clear or cloudy open water. Gizzard shad mainly eat plankton, algae, and plant bits. They can live up to 10 to 11 years, but usually live 5 to 7 years. They can reach lengths up to 18 inches, but are typically 8 to 14 inches.

Threadfin Shad

The Threadfin shad (Dorosoma petenense) is not native to Colorado. Threadfin shad are usually found in large rivers, lakes, and reservoirs, often near rocky banks or in open water. They generally eat algae, plankton, and tiny organisms. Threadfin shad typically grow to about 5 to 7 inches, but can reach 9 inches.

Cichlids: A Diverse Family

This family is known for its wide variety of species.

Tilapia

Tilapia (Tilapia spp.) are not native to Colorado. They come from Africa and the Jordan Valley. They are raised for food and have established populations in many states.

Sculpins: Small Bottom Dwellers

Sculpins are small fish that live on the bottom of bodies of water.

Mottled Sculpin

The Mottled sculpin (Cottus bairdi) is native to Colorado. Mottled sculpins are generally found in creeks, rivers, lakes, and reservoirs. They prefer areas with gravel or rocky bottoms and fast-moving water. They eat aquatic insects, larvae, small water creatures, small fish, and fish eggs. Mottled sculpins typically grow to 3-3.6 inches, but can reach 5 inches. Their lifespan is usually around three years.

Paiute Sculpin

The Paiute sculpin (Cottus beldingi) is native to Colorado. Paiute sculpins are usually found in cold, clear streams with rocky bottoms, but can also be found in lakes. They mainly eat snails, algae, and decaying plant matter. Paiute sculpins can reach a length of 2.5 to 4 inches, but have been known to grow to 5 inches.

Minnows and Carps: The Largest Fish Family

This is the biggest family of fish, with many different types of minnows and carps.

Central Stoneroller

The Central stoneroller (Campostoma anomalum) is native to Colorado. Central stonerollers can be found in streams with sand or gravel bottoms. They prefer areas with fast-moving shallow water (riffles) and deeper calm spots (pools). They can live in many different waters as long as there is food. Central stonerollers eat algae and decaying plant matter. They typically range from 3 to 5 inches long, but can reach 7 inches.

Goldfish

Goldfish (Carassius auratus) are not native to Colorado. They originally came from China. Goldfish prefer slow-moving waters. They are similar to their cousin, the common carp. Goldfish thrive in murky waters with plants and dirt at the bottom. They eat plants, insects, insect larvae, small water creatures, and tiny animals floating in the water. Goldfish are known to live very long lives, up to 41 years!

Lake Chub

The Lake chub (Couesius plumbeus) is native to Colorado. The Lake chub is generally found in lakes, but also in cold, clear rivers and streams. They usually prefer shallow waters with sandy bottoms. Young lake chubs eat small water creatures, while adults switch to eating insects.

Grass Carp

The Grass carp (Ctenopharyngodon idella) is not native to Colorado. Grass carp usually live in lakes, ponds, pools, and calm backwaters. They generally stay close to shallow waters because they are herbivores, meaning they eat aquatic plants. Grass carp can grow up to 48 inches long and weigh up to 50 pounds, though typical sizes are 24 inches and 14 pounds.

Red Shiner

The Red shiner (Cyprinella lutrensis) is native to Colorado. The Red shiner lives in streams and rivers with deeper pools and silty conditions. They mainly eat aquatic insects and algae. Red shiners tend to reach an average length of 3 inches.

Common Carp

The Common carp (Cyprinus carpio) is not native to Colorado. Common carp are known to live in lakes, ponds, and rivers. They eat both plants and animals, including plants, decaying matter, algae, small water creatures, and bottom-dwelling organisms. Common carp typically grow to 1 to 2 feet long and weigh 1 to 8 pounds, but some have been known to reach 30 or 40 pounds. They can live very long lives, with some reported to be up to 47 years old. This species is vulnerable.

Utah Chub

The Utah chub (Gila atraria) is found in the Snake River, Lake Bonneville, and Missouri Basins. It is also found in the Colorado and Great Salt Lake drainage systems.

Humpback Chub

The Humpback chub (Gila cypha) is native to Colorado. It lives only in rivers, preferring slower, calm spots (eddies) and pools with sand, gravel, or rocky bottoms. Humpback chubs can reach lengths of 20 inches and weigh up to 2.5 pounds. They are known to be long-lived fish, with a lifespan of up to 30 years. The Humpback chub eats insects, small water creatures, plants, seeds, small fish, and even reptiles. This species is endangered.

Brassy Minnow

The Brassy minnow (Hybognathus hankinsoni) is native to Colorado. The brassy minnow lives in stream channels, pools, calm backwaters, and beaver ponds with lots of plants. Their diet mainly consists of plankton. Brassy minnows typically grow to lengths of 2 to 3 inches.

Plains Minnow

The Plains minnow (Hybognathus placitus) is native to Colorado. The Plains minnow can be found in shallow streams or small to large rivers with sandy bottoms. A typical plains minnow is about 5 inches long. They generally eat algae, organic materials, and some small water creatures.

Bonytail Chub

The Bonytail chub (Gila elegans) is native to Colorado. The bonytail chub is usually found in streams and rivers. They can grow to be over 2 feet long and live over 30 years. The main diet of a Bonytail chub is insects, small fish, worms, algae, plankton, and plant debris. This species is critically endangered.

Rio Grande Chub

The Rio Grande chub (Gila pandora) is native to Colorado. The Rio Grande chub lives in streams, reservoirs, and lakes. They are also known to live in man-made waterways and irrigation ditches. They usually prefer areas with sand and cobble bottoms. Rio Grande Chubs eat plants, decaying matter, small water creatures, insects, plankton, and small fish. They can grow as long as 12 inches, but in Colorado, they are usually about 5 inches long.

Roundtail Chub

The Roundtail chub (Gila robusta) is native to Colorado. The Roundtail chub lives in rivers and streams, often in the deepest pools available. They find areas with cover like boulders, overhanging cliffs, and plants. The Roundtail chub can live up to 7 years and typically grows to 9 to 12 inches long, but some have been reported to be at least 19 inches long. Their diet consists of aquatic insects and larvae.

Common Shiner

The Common shiner (Luxilus cornutus) is native to Colorado. The Common shiner lives in lakes and rivers. In lakes, they prefer plant-filled areas, and in rivers, they live in areas with gravel and rubble bottoms. Common shiners eat aquatic insects, larvae, and algae. They usually grow up to 6 to 7 inches long.

Speckled Chub

The Speckled chub (Macrhybopsis aestivalis) is native to Colorado. The Speckled chub is usually found in small to large rivers with sand or gravel bottoms. Speckled chub eat aquatic insects and larvae. The speckled Chub usually grows up to 3 inches long, but can reach a maximum length of 6 inches.

Hornyhead Chub

The Hornyhead chub (Nocomis biguttatus) is native to Colorado. The Hornyhead chub lives in streams with gravel and sand bottoms. They also prefer streams with slower currents. The Hornyhead chub eats aquatic insects and land insects. They usually grow to 4-7 inches long, but are known to reach lengths of up to 9 inches.

River Shiner

The River shiner (Notropis blennius) is not native to Colorado. The River shiner lives in rivers and streams that usually have sand or gravel bottoms. The River shiner's diet usually consists of small water creatures and land insects. River shiners are typically 3-4 inches long, but can reach 5 inches.

Golden Shiner

The Golden shiner (Notemigonus crysoleucas) is not native to Colorado. The Golden shiner is usually found in calm, quiet waters like lakes, ponds, and calm channels with aquatic plants. Their diet usually consists of small water creatures, algae, insects, and plankton. Golden shiners grow to be about 3-7 inches long, but are known to exceed 12 inches.

Bigmouth Shiner

The Bigmouth shiner (Notropis dorsalis) is native to Colorado. They are most likely found in pools from creeks and rivers with a sandy bottom. The Bigmouth shiner eats aquatic insects, land insects, and algae. The typical length of a bigmouth shiner is 2 to 3 inches, but can reach 3.5 inches.

Arkansas River Shiner

The Arkansas River shiner (Notropis girardi) is not native to Colorado. The Arkansas river shiner lives in large rivers and streams with shallow sandy bottoms. Arkansas river shiners usually eat small aquatic insects, small water creatures, and insect larvae. Adult Arkansas river shiners grow to about 2 inches long. This species is vulnerable.

Spottail Shiner

The Spottail shiner (Notropis hudsonius) is not native to Colorado. Spottail shiners live in lakes or rivers and are often found over sand or gravel. The spottail shiner eats aquatic insects, plankton, and tiny water fleas. Spottail shiners typically reach lengths of 3.5 to 6 inches long.

Sand Shiner

The Sand shiner (Notropis stramineus) is native to Colorado. They live in rivers of various sizes, as well as streams with sand or fine gravel bottoms. Depending on the region, sand shiners prefer clearer water over cloudy water, or vice versa. Sand shiners eat aquatic insects, land insects, and also tiny plant-like organisms (phytoplankton). Sand Shiners have a lifespan of about three years and grow to about 4.4 cm to 8.2 cm.

Suckermouth Minnow

The Suckermouth minnow (Phenacobius mirabilis) is native to Colorado. They live in medium to large rivers and prefer cloudy waters. The Suckermouth minnow eats small water creatures like midge larvae and pupae, as well as plankton. The suckermouth minnow reaches up to 2 to 4 inches long, but it's not uncommon for them to reach 5 inches.

Northern Redbelly Dace

The Northern redbelly dace (Phoxinus eos) is native to Colorado. Northern redbelly dace usually live in streams with lots of aquatic plants. Northern redbelly dace grow to about 3 inches long and weigh about 2 grams. They usually live up to about 3 years. Their daily diet consists of algae, diatoms, water fleas, and small insect larvae.

Southern Redbelly Dace

The Southern redbelly dace (Phoxinus erythrogaster) is native to Colorado. They live in cold, clear streams with sand, gravel, or mud bottoms. The Southern redbelly also prefers areas with overhanging plants that provide cover over the banks. The Southern redbelly dace eats algae, aquatic insects, and decaying plant matter.

Fathead Minnow

The Fathead minnow (Pimephales promelas) is native to Colorado. They live in small streams, ponds, and lakes. They can tolerate most types of water clarity and pH levels. Fathead minnows eat organic debris, aquatic insects, and tiny animals floating in the water (zooplankton) in their daily diet. Fathead minnows can grow up to 4 inches long, but usually range between 2-3 inches.

Flathead Chub

The Flathead chub (Platygobio gracilis) is native to Colorado. The Flathead chub lives in rivers and streams with moderate levels of cloudiness. They also prefer areas with gravel bottoms. Flathead chubs eat aquatic insects, land insects, and algae in their daily diet. The Flathead chub can grow up to 12 inches long.

Colorado Pikeminnow

The Colorado pikeminnow (Ptychocheilus lucius) is native to Colorado. The Colorado pikeminnow usually lives in rivers and quiet backwaters. Young Colorado pikeminnow eat insects and plankton, while adults mainly eat fish. Colorado pikeminnow are one of the largest minnows, typically reaching lengths of 20 inches, with the biggest reported being 70 inches long! This species is endangered.

Bullhead Minnow

The Bullhead minnow (Pimephales vigilax) is found in the Mississippi River Basin and extends into the Gulf Slope drainages into the Rio Grande system.

Longnose Dace

The Longnose dace (Rhinichthys cataractae) is native to Colorado. Longnose dace usually live in lakes, streams, and springs with rocky bottoms. The Longnose dace eats aquatic insects, algae, and fish eggs. The average longnose dace is typically 2 to 4 inches long, but some are known to reach about 5 inches.

Speckled Dace

The Speckled dace (Rhinichthys osculus) is native to Colorado. The Speckled dace usually lives in streams, springs, lakes, and rivers. They prefer quiet, clear, and well-oxygenated water. The speckled dace eats small water creatures, algae, nymphs, and plankton. Speckled dace typically grow to about 4 inches long and live up to three years.

Redside Shiner

The Redside shiner (Richardsonius balteatus) is not native to Colorado. The Redside shiner lives in lakes, ponds, and rivers with slow or no current. The Redside shiner eats plankton, aquatic insects, and snails. Redside shiners grow to a length of about 7 inches long.

Creek Chub

The Creek chub (Semotilus atromaculatus) is native to Colorado. The Creek chub usually lives in small streams. Creek chubs eat insects, small fish, crayfish, worms, and snails. Creek chubs typically measure up to 4 to 8 inches long and can reach up to 12 inches.

Tench

The Tench (Tinca tinca) is not native to Colorado. The Tench usually lives in shallow lakes, rivers, and calm backwaters with lots of plants. The Tench eats algae, plants, decaying matter, snails, mosquito larvae, and other small organisms. Tench can reach up to 33 inches long, weigh up to 16.5 pounds, and live up to 20 years.

Pikes: Top Predators

Pikes are known for being fierce hunters in their watery homes.

Northern Pike

The Northern pike (Esox lucius) is not native to Colorado. The Northern pike lives in streams, large rivers, and lakes with dense plants. The Northern pike is a meat-eating fish. It eats fish, frogs, waterfowl, and anything smaller than itself. Northern pike are known to be 24 to 30 inches long and weigh 3 to 7 pounds. The largest pike ever known was 58 inches long and weighed 68 pounds!

Tiger Muskellunge

The Tiger muskellunge (E. lucius × E. masquinongy) is not native to Colorado. The Tiger Muskellunge lives in lakes and large rivers with rocky bottoms and lots of cover. They also prefer shallow waters. Tiger Muskellunge eat fish, frogs, waterfowl, mice, and other small mammals and birds. The Tiger Muskellunge can grow up to 22 to 50 inches long and weigh from 3 to 40 pounds. They can live up to 10 years.

Killifish and Topminnows: Surface Dwellers

These small fish often swim near the water's surface.

Plains Topminnow

The Plains topminnow (Fundulus sciadicus) is native to Colorado. The Plains topminnow usually lives in streams, oxbows (U-shaped bends in rivers), and ditches. They generally eat insects, tiny crustaceans, snails, and other small water creatures. The Plains topminnow rarely grows larger than 2.5 inches long.

Plains Killifish

The Plains killifish (Fundulus zebrinus) is native to Colorado. The Plains killifish lives in shallow, sandy runs, ponds, and streams with sandy bottoms. The plains killifish will reach about 4 inches long and will have a life span of 3 years.

Sticklebacks: Unique Spawning Habits

Sticklebacks are small fish known for the spines on their backs and their interesting nesting behaviors.

Brook Stickleback

The Brook stickleback (Culaea inconstans) is not native to Colorado. The Brook stickleback lives in rivers, streams, lakes, and ponds that have cool, clear waters with lots of plants. The Brook stickleback grows to about 2.4 inches and lives up to 3 years.

Catfish: Whiskered Wonders

Catfish are easily recognized by their whisker-like barbels around their mouths.

Black Bullhead

The Black bullhead (Ameiurus melas) is a native species to Colorado. The black bullhead lives in small creeks, rivers, ponds, and lakes. The Black bullhead eats tiny crustaceans and insects. Black bullheads usually live for about five years. Their typical lengths are about 4 to 14 inches, and they weigh about 1.5 to 8 pounds.

Yellow Bullhead

The Yellow bullhead (Ameiurus natalis) is a non-native species in Colorado. The Yellow bullhead lives in streams, lakes, ponds, and large bays with rock, sand, and clay bottoms. The Yellow bullhead also eats minnows, crayfish, insects, larvae, aquatic insects, worms, and plants. The Yellow bullhead has an average life span of 4 years and can grow from 8 inches to 10 inches long.

Brown Bullhead

The Brown bullhead (Ameiurus nebulosus) can be found in lakes and rivers. They eat fish, crayfish, and aquatic insects, but will often scavenge on dead fish or other animals. Brown bullheads typically grow to 8 to 16 inches long and weigh 1 to 2 pounds. They have been known to grow up to 20 inches long and weigh about 4 pounds.

Blue Catfish

The Blue catfish (Ictalurus furcatus) can be found in rivers, lakes, and reservoirs with bottoms that can be hard or soft, like gravel, boulders, rocks, sand, and silt. The Blue catfish eats fish, crayfish, snails, and frogs. Blue catfish can grow up to 5 feet long and weigh more than 100 pounds! Blue catfish look a lot like channel catfish, but their anal fin (bottom fin) is different.

Channel Catfish

The Channel catfish (Ictalurus punctatus) lives in rivers, streams, lakes, ponds, and reservoirs. They prefer clean, well-oxygenated water. Their diet consists of small water creatures, clams, snails, aquatic insects, fish, birds, and other small animals. Channel catfish can get up to 52 inches long and weigh almost 58 pounds. The oldest reported channel catfish lived for about 24 years.

Flathead Catfish

The Flathead catfish (Pylodictus olivaris) can be found in large bodies of water, like big rivers with deep pools or lots of cover like driftwood and timber. They eat whatever is available to them, including insects, crayfish, clams, and small fish like sunfish, shiners, and shad. They use their whiskers (barbels) and taste buds on their skin to find food. They grow quickly and can reach 30 inches or more, weighing up to 50 pounds.

Stonecat

The Stonecat (Noturus flavus) is found in large creeks and small rivers. Stonecats use their whiskers (barbels) and taste buds on their skin to find food. They eat insects, aquatic crustaceans, and fish. They can live up to 7 years and grow up to 12 inches long.

Temperate Basses: Strong Swimmers

These fish are known for their strong swimming abilities and are often found in open water.

Wiper (Hybrid Striped Bass)

The Wiper (hybrid striped bass) (M. chrysops × M. saxatilis) is a mix between a white bass and a striped bass. Wiper eat the same things as white and striped bass, mainly gizzard shad, silversides, yellow perch, and various sunfish. Wiper prefer open water and only come close to shore or rocks when chasing baitfish. They are stocked in large lakes and reservoirs and can also be found in rivers. Wiper are known to grow more than 30 inches and can weigh 27 pounds or more.

White Bass

The White bass (Morone chrysops) lives in lakes, ponds, and rivers. White bass do not like muddy water or areas with many plants. They prefer open water or rocky areas. White bass eat small water creatures like tiny crustaceans, midge larvae, and small fish. White bass commonly reach 12.5 inches long, but can grow up to 17 inches or more. The longest living white bass recorded was 9 years. The climate often affects how long it takes a White Bass to become an adult.

Striped Bass

The Striped bass (Morone saxatilis) lives in both freshwater and saltwater. Striped bass can grow up to 6 feet 6 inches or more. They can also weigh up to 125 pounds, and females are usually bigger than males. They live in rivers, lakes, reservoirs, and along the Atlantic, Gulf of Mexico, and Pacific Coasts of North America. Striped bass are opportunistic predators, meaning they eat whatever they can find. Their diet includes plankton, insects, small water creatures, small fish, eels, shrimp, and worms.

Smelts: Small and Silvery

Smelts are small, silvery fish often found in cooler waters.

Rainbow Smelt

The Rainbow smelt (Osmerus mordax) is an invasive species, meaning it is not native and can harm the local environment. Rainbow smelt travel from saltwater to freshwater streams to lay their eggs. They can also live entirely in freshwater, inhabiting rivers, streams, lakes, and reservoirs. They are invasive because they eat the larvae and food resources of other species, as well as fish eggs. They are known to negatively impact ecosystems and can grow to 7 to 9 inches. They were introduced into Horsetooth Reservoir, but their population decreased, and it's unclear if they survived due to water temperature.

Perches and Darters: Colorful and Active

This family includes many popular game fish and smaller, often colorful, darters.

Arkansas Darter

The Arkansas darter (Etheostoma cragini) lives in shallow creeks with sandy bottoms. They eat various aquatic insects and some plants, including small seeds. They have only been recorded to grow up to 2.5 inches. Their maximum age is three years. Their population is declining in Arkansas but is more common in Missouri. This species is near threatened.

Iowa Darter

The Iowa darter (Etheostoma exile) has a slender body and a very short snout. Males are known to have blue blotches during breeding times. They are native to Colorado and mainly found only in the South Platte River. They are usually 1.5-2.5 inches long, but some can get up to 3 inches. Darters are found in natural lakes and very sluggish streams or marshes with moderate aquatic plants and clear waters. They eat insect larvae, small water creatures, and other aquatic insects.

Johnny Darter

The Johnny darter (Etheostoma nigrum) is one of the first fish to move to new locations and re-establish populations. They prefer clean water and sandy gravel bottoms in still or slow-moving water. They mainly eat water fleas, midge larvae, mayfly larvae, and caddisfly larvae. They usually grow up to 2.5 inches for males and 2.3 inches for females. They can live up to 3 years.

Orangethroat Darter

The Orangethroat darter (Etheostoma spectabile) is a species of great conservation need. They are found only in streams and feed on bottom-dwelling insects and other small water creatures. They sometimes eat fish eggs. They can grow up to 3 inches. Females have similar patterns to males but with muted brown colors.

Logperch

The Logperch (Percina caprodes) is hard to find and very rare in Colorado. They live in shallow water of rivers and creeks, but can also be found in large rivers, lakes, and reservoirs. They prefer fast-moving water with sand and gravel bottoms. They like to lay their eggs in the sand of lakes and streams. They prefer to eat non-insect small water creatures, but also eat eggs, insects, snails, worms, and aquatic crustaceans. They can grow up to 13 to 18 cm and can live up to 4 years.

Yellow Perch

The Yellow perch (Perca flavescens) is found in ponds, lakes, slow-moving rivers, and creeks. Yellow Perch prefer clear water closest to plants and tend to swim in schools near shore. Yellow perch eat a wide variety of small water creatures and smaller fish. Yellow Perch can grow up to 19.7 inches and can live up to 11 years or more.

Sauger

The Sauger (Sander canadense) is found in rivers and large lakes and prefers moderate to fast currents. They like water close to 19.6 °C and are closely related to walleyes. Their diet consists of insects, aquatic crustaceans, tiny animals floating in the water (zooplankton), but when they get bigger, they mainly eat fish. Female saugers can lay up to 50,000 eggs, and they can live up to 13 years. They can grow up to 25 inches, maybe more.

Walleye

The Walleye (Sander viterus) is a commonly stocked game fish. The walleye has large, sharp teeth. Walleye like cold, deep, quieter water in rivers, lakes, and reservoirs. Walleye are mostly active at night and prefer to hide in tree roots, logs, and aquatic plants during the day. Since they are mostly nocturnal, they hunt more during the night. Their diet depends on small fish, large water creatures, and insects. They will hunt during the day too, but prefer nights. Walleyes can get as big as 3 feet and weigh as much as 20 pounds.

Bigscale Logperch

The Bigscale logperch (Percina macrolepida) is not native to Colorado and hard to find here. It is found in large rivers or lakes, but can also be found in small streams. They can grow up to 95mm and eat a variety of bottom-dwelling insects. They lack a swim bladder, so they spend a lot of time on the bottom of small streams or lakes.

Livebearers: Giving Birth to Live Young

This family includes fish that give birth to live young instead of laying eggs.

Western Mosquitofish

The Western mosquitofish (Gambusia affinis) has been introduced throughout the U.S. and the world because it eats mosquitoes. Its diet consists of aquatic insects, eggs of fish and amphibians, algae, and other small fish. Western Mosquitofish can grow up to 7 cm, but they can have a large impact on ecosystems, both good and bad.

Salmon and Trout: Cold Water Beauties

This family includes many popular sport fish known for living in cold, clear waters.

Snake River Cutthroat Trout

The Snake River cutthroat trout (Oncorhynchus clarki behnkei) was introduced as a sport fish in areas other than the Snake River. They live in large rivers, small streams, lakes, and reservoirs. They prefer good overhead or underwater cover to hide from predators and to ambush prey. Their diet consists of aquatic insects and plankton. They can also reach up to 12 inches long and start eating smaller fish and crayfish.

Colorado River Cutthroat Trout

The Colorado River cutthroat trout (Oncorhynchus clarki pleuriticus) is considered one of the most beautiful trout in North America because of its red color from its lower mouth to its belly. These trout are found in high-country lakes and streams in the cool mountains. This native subspecies eats aquatic and land insects and can grow up to 12 inches.

Greenback Cutthroat Trout

The Greenback cutthroat trout (Oncorhynchus clarki stomias) is an endangered species that is currently in the process of recovering its population. Greenback cutthroat trout eat aquatic and land insects, but they are also known to eat whatever they can find. They live in rivers and lakes. It's actually very rare to find a greenback cutthroat trout 10 inches long.

Rio Grande Cutthroat Trout

The Rio Grande cutthroat trout (Oncorhynchus clarki virginalis) is found in high elevation streams and lakes. Rio Grande Cutthroat trout are generalist feeders, meaning they eat a variety of things, including aquatic and land insects, and other smaller fish. Due to the size of the rivers they live in, they can only grow to a length of 10 to 12 inches.

Rainbow Trout

The Rainbow trout (Oncorhynchus mykiss) eats aquatic insects, grasshoppers, worms, salamanders, crayfish, and other fish. Rainbow trout will go search for food if there is none in their area. They live in rivers, streams, lakes, and reservoirs and usually grow much faster than other trout. Rainbow trout can live up to 11 years and grow up to 16 inches or more.

Golden Trout

The Golden trout (Oncorhynchus mykiss aguabonita) are small members of the trout family. They live in high-altitude lakes and rivers, from ranges of 9000 to 12000 feet, where temperatures are low. They feed on small insects, larvae, aquatic insects, and small water creatures. The biggest golden trout caught was 28 inches long and weighed 11.25 pounds.

Sockeye Salmon

The Sockeye salmon (Oncorhynchus nerka) is a species that hatches in freshwater streams, rivers, or lakes and then travels to the ocean to feed and grow. When it's time to breed, they return to the freshwater where they were born to lay eggs. While in fresh water, they eat insects, tiny animals floating in the water (zooplankton), and small crustaceans. In the ocean, they eat zooplankton, small larvae, small fish, and squid. They can grow up to 1.5 to 2.5 feet long and weigh up to 4 to 15 pounds before returning to their spawning grounds.

Mountain Whitefish

The Mountain whitefish (Prosopium williamsoni) is found in western North America in lakes, rivers, and streams in the Rocky Mountain region. They live in the lower regions of Colorado where it is not as cold. They are known for their small mouths, so they eat small insects and crustaceans. They are important for trout because trout rely on their young and eggs to get ready for the winter season. Their population is important because it could affect the trout population.

Arctic Char

The Arctic char (Salvelinus alpinus) can live in the ocean but lay eggs in freshwater streams, or they can stay in freshwater for their entire lives. Their color changes depending on the environment and water. Char's diet changes with the seasons. They can eat aquatic insects, salmon eggs, snails, small water creatures, and fish during spring and summer. In the fall and winter, they change their diet and start eating tiny animals floating in the water (zooplankton), freshwater shrimp, and small fish. They can weigh up to 20 pounds and grow more than 30 inches.

Brook Trout

The Brook trout (Salvelinus fontinalis) is native to headwater and small streams in northeastern and southeastern Minnesota, but they have been introduced to Colorado lakes and rivers. Brook trout prefer habitats with sand and gravel bottoms and plants. They like living in headwater ponds and rivers, but can also be found in lakes. Brook trout eat small insects and other aquatic insects, but as they get bigger, they start to feed on minnows and other small fish. They can grow up to 6 to 10 inches in small streams, rivers, and lakes. Some in lakes can get as big as 24 inches.

Lake Trout

The Lake trout (Salvelinus namaycush) lives in deep parts of lakes. They rarely live in slightly salty water and also in some rivers and streams. Lake trout eat a variety of organisms like small water creatures, insects, fish, and small animals. Some can eat tiny animals floating in the water (plankton) throughout their whole life, but they will grow slowly and be smaller in size. Lake trout can grow up to 59 inches and can live up to 40 years or more.

Splake

The Splake (Salvelinus namaycush × S.fontinalis) is a mix between a lake trout and a brook trout. Splake were introduced by the Ministry of Natural Resources and do well in small bodies of water that stay cool throughout the year. They are raised in hatcheries. The diet of Splake is the same as a brook trout, eating plankton, insects, crayfish, and small fish. They grow up to 20 inches and more quickly than their parent species. Splakes can live as long as 20 years. The second generation of Splake offspring have a harder time living and higher death rates.

Brown Trout

The Brown trout (Salmo trutta) is not native to North America. They were brought to North America and live in lakes and rivers. Brown trout grow fast until they become adults and can grow as long as 25 inches and weigh as much as 16 pounds. They are usually smaller in rivers than in lakes. Brown trout are active feeders and will eat insects, tiny animals floating in the water (zooplankton), worms, crayfish, small clams, snails, small fish like trout and minnows, young mink, and turtles. Brown trout do not die after laying eggs and will lay eggs multiple years in the same area.

Arctic Grayling

The Arctic grayling (Thymallus arcticus) is known to swim 60 miles between habitats. Arctic graylings like to live in clear, cold, open water habitats with high amounts of oxygen, like rivers and lakes. Arctic grayling eat tiny animals floating in the water (zooplankton), insects, fish, fish eggs, lemmings, and small water creatures. They can grow up to 13.5 inches and weigh 8.4 pounds. The oldest Arctic grayling was 18 years old.

Drums: Making Sounds Underwater

This family includes fish that can make drumming sounds.

Freshwater Drum

The Freshwater drum (Aplodinotus grunniens) lives in medium to large rivers and reservoirs in deep or open water. They can grow up to 20 inches or more and weigh up to 38 pounds. Freshwater drums are bottom feeders and also eat meat. They eat small fish, crayfish, aquatic insects, clams, and snails. They have strong teeth in their throat to crush the shells of snails and clams. They are called "drum" because they can make a noise or sound by rapidly contracting their belly muscles against their air bladder. This usually happens during mating season.