Set apart by its extensive plains, dense forests, and sizeable wetlands, Iowa has a diversity of natural resources. Its western and eastern borders are almost entirely made up of river systems; it shares the Mississippi River with both Wisconsin and Illinois in the east, whereas both the Big Sioux and Missouri rivers occupy its western perimeter. In between these three rivers lies thousands of acres of lakes, reservoirs, and meandering streams.
Surface water is an incredibly important resource in Iowa because it helps support the local agricultural industry. Fortunately, many high-quality waters are now provided with special protection to minimize the impacts of damage from polluted run-off and livestock waste. Found all throughout the state, these are home to close to 150 species of freshwater fish.
With over 40 million fish caught by both local and visiting anglers each year, fishing significantly impacts Iowa’s economy. Anglers praise the state as an exceptional destination for natural and stocked trout, prize-sized bass, and abundant panfish. The species listed below represent the fish communities found in some of the most accessible areas. These include non-game natives, commercially valuable gamefish, and federally protected species.
Fish Species in Iowa
1) Brook trout (Salvelinus fontinalis)
Brook trout tend to be most concentrated in the small streams of northeastern Iowa. They spend the majority of their time in the riffle zones of pools, where they feed in rapidly moving waters and rest in the structurally diverse zones of rocky or vegetated banks. Their natural populations are known for being quite sensitive to water quality and ambient temperatures, so they are restricted to only the cleanest and coolest of streams.
Compared to other common trout species, the wild specimen of brook trout is distinguished by an abundance of yellow and red spots on its sides. Occasionally, the spots may be further enhanced by blue borders. Beneath the spots are brownish streaks above a darker, possibly mottled, background of deeper hues. In optimal conditions, this fish can grow to about 25 inches (64 cm) long. The state record was caught in 1996 and measured 19.75 inches (50 cm) long.
2) American paddlefish (Polyodon spathula)
The American paddlefish is largely concentrated in the tributaries of the Mississippi and Missouri rivers. However, anglers may also be lucky enough to find it in connecting streams and lakes. This seemingly prehistoric fish is best targeted in spring, where it may readily be found below dams. Individuals inhabiting Iowa are fairly long-lived and may measure close to six feet (1.8 meters) long at maturity. They are thus considered freshwater giants.
Named for their elongated, paddle-shaped rostrums, this primitive species sports a body that resembles that of a shark in that it is mostly cartilaginous. But unlike sharks, its large jaws possess no teeth. Its specialized “paddle” is equipped with sensory receptors that detect zooplankton and aquatic insects in the water column. When swarms of these are present, the paddlefish is able to flaunt its highly evolved skills as a ram suspension feeder.
3) Northern pike (Esox lucius)
A fantastic source of flaky, protein-rich flesh, the northern pike makes for great table fare wherever it is naturally found. This carnivorous freshwater fish favors heavily vegetated, slow-moving streams and rivers. As an ambush predator, it is usually most successful when there is ample vegetation to hide it from unsuspecting schools of panfish and perch. Its diet tends to be influenced by whatever is available, so it may shift to carnivory wherever food is scarce.
Named for the weapon-like form of its elongated body, the northern pike grows to an average mature length of around 16 – 22 inches (41 – 56 cm) long. It is distributed throughout much of Iowa and has shown reproductive success in a variety of freshwater environments – from large rivers to man-made water systems. Its abundance is highest in the Mississippi River and its tributaries.
4) Bigmouth buffalo (Ictiobus cyprinellus)
As suggested by its common name, this member of the Catostomidae or sucker family does truly have a large mouth for its head. The largest member of its genus of buffalo fishes, Ictiobus, it has a remarkably long lifespan. Recent studies have revealed its capacity to live for more than 100 years in productive and pristine waters. It is thus unsurprising that it can grow to around 4 feet (1.2 meters) long and weigh as much as 80 pounds (36 kg)!
Iowa’s state record for this species was caught in Lake Manawa in 2007. It weighed a whopping 64 pounds and 6 ounces (29.2 kg). Sizeable stocks are found in lakes and tributaries, particularly those associated with the Mississippi and Missouri rivers. In these freshwater systems, they feed on copepods, water fleas, phytoplankton, and small insects.
5) Walleye (Sander vitreus)
An experienced angler favorite due to its preference for choppy and stained waters, the walleye is found in all of Iowa’s major lakes and rivers. This member of the Percidae family thrives in cool, sandy-bottomed freshwater features. It may migrate from shallow waters to deeper pools throughout the course of a single day. It does so to competitively feed, during which it uses its optic adaptations to target prey.
“Walleye chop” refers to fairly turbulent waters, typically beneath an overcast sky. It is in these conditions that walleyes tend to hunt. It also happens to be the best time to catch them with live bait. In Iowa, anglers use crankbaits to successfully lure them and draw attention to their energetic, feisty nature.
6) Bluegill (Lepomis macrochirus)
One of the most important forage fish, the bluegill plays multiple roles wherever it is found. It emphasizes the value of small to medium-sized fish, which are crucial for the survival of larger game species. Its populations are kept in check by its predators, while it, in turn, feeds on a wide range of smaller fish, crustaceans, amphibian larvae, and aquatic insects. The total removal of this species from some of its native habitats can cause the food chain to collapse, leading to an irreversible string of ecological consequences.
Also known as coppernose, bream, and “sunny”, the bluegill is the most widespread member of the Centrarchidae family in Iowa and in several of its surrounding states. Its local populations are especially abundant in the state’s eastern waters – particularly those connected to the Mississippi River. It is also often stocked into man-made ponds and impoundments.
7) Black crappie (Pomoxis nigromaculatus)
The black crappie is another ubiquitous species throughout its native range. This sunfish is heavily speckled with black markings, providing it with a mottled appearance. The white crappie (P. annularis), a close relative with which it shares its general morphology, has a “cleaner” appearance. Both species are found in Iowa’s lakes, rivers, reservoirs, ponds, and sloughs. They tend to favor clear, slow-moving waters.
This prolific fish is known for overpopulating freshwater systems that do not contain an abundance of its predators. It has a knack for having high spawning success rates. To make matters worse, its juveniles can quickly reach sexual maturity in optimal conditions. Aquatic biologists often warn against generously stocking this species in ponds, though it is generally a better choice when compared to white crappie.
8) Flathead catfish (Pylodictis olivaris)
One of the most abundant types of catfish in Iowa’s bordering rivers, the flathead catfish can grow to massive proportions. This hefty ictalurid can easily weigh more than 100 pounds (45 kg) at maturity, making it almost as heavy as the continent’s largest catfish, the blue cat (Ictalurus furcatus). Unlike the latter, however, it has rounded fins and a preference for murky, still water.
The flathead catfish is found in many of Indiana’s reservoirs and interior streams. Of course, its populations also extend throughout the state’s largest river systems and lakes. Its smaller specimens subsist on a diet of minnows and aquatic insects, while its larger ones tend to consume both live and dead fish. Tolerant of high turbidity, they often rely on vibrations to find prey.
9) Largemouth bass (Micropterus salmoides)
A voracious carnivore, the largemouth bass is an apex predator in Iowa’s freshwater systems. This gamefish is set apart by its massive gape, which allows it to consume prey items that are close to half its full size. In the absence of a sufficient number of smaller fish, it will not hesitate to eat amphibians and snakes. It may also feed on its own smaller conspecifics when hard-pressed to find other suitable prey.
This massive member of the sunfish family is abundant in the sloughs, oxbow lakes, backwaters, and impoundments connected to the Mississippi River. It may also be found, albeit in smaller populations, in interior stream systems with quiet currents. Its specimens are typically spotted as they lurk through submerged, vertical vegetation and around dock structures.
10) Muskellunge (Esox masquinongy)
Self-sustaining muskellunge populations are found in but a few segments of the Mississippi River and its tributaries. Nowadays, several creeks are regularly stocked with juveniles to meet the annual demands of both local and visiting anglers. This stunning fish is the largest among all pikes. Its size is matched by its voraciousness as a stealthy carnivore. It may creep through vegetated lake channels in search of smaller fish, frogs, young birds, and even small mammals.
Dubbed the “fish of 10,000 casts”, the muskellunge is known for being quite challenging to lure and successfully catch. Experienced fishers usually emphasize the need to use large artificial lures, particularly those that generate vibrations in the water. Of course, this fish is well worth the challenge, as it always leaves anglers with a memorable experience.
11) Channel catfish (Ictalurus punctatus)
The most widespread and abundant catfish species in the US, the channel cat is now extremely popular as a sport fish and as an aquaculture species. Able to thrive in waters with limited light, it has developed several sensory adaptations to compete with other predators. In turbid waters, this skilled omnivore relies on its external taste buds and on external vibrations to find prey. Its juveniles may consume plant material, while its adults are more likely to feed on a wider variation of fish, insects, and amphibians.
Iowa’s channel catfish populations are distributed throughout its rivers and streams. A notably adaptable species, it can survive in water systems with no current and with minimal dissolved oxygen concentrations. During flooding periods, this opportunist tends to move into smaller creeks with fallen logs and other forms of organic structure. Once currents slow down, it may venture back into deeper zones.
12) Fathead minnow (Pimephales promelas)
A small cyprinid with a tolerance for a wide range of environmental conditions, the fathead minnow is one of Iowa’s most widespread fish species. Found in virtually all natural water systems and several manmade ponds throughout the state, it is commercially valued as a prime type of baitfish. As it grows to just 2.8 – 4 inches (7 – 10 cm) long, it is preyed on by practically all carnivorous gamefish species in the state.
The largest schools of the fathead minnow are usually found in sluggish waters with clay-based or silty bottom substrates. Though it can maintain an omnivorous diet, it has the tendency to rely on its benthic filter-feeding skills to catch small prey. This humble minnow deserves the appreciation of all anglers as it supports the needs of many of Iowa’s most important freshwater gamefish.
13) Johnny darter (Etheostoma nigrum)
Another tiny yet ecologically valuable fish, the johnny darter grows to a maximum length of around 2.8 inches (7 cm). Though it is one of Iowa’s smaller darters, it is memorable for its speckled colors and patterned fins. This member of the Percidae family is found in most of Iowa’s freshwater systems. It favors conditions in sandy or rocky streams, but it can also survive in both natural and man-made pools.
Johnny darters have a morphology that allows them to remain perfectly perched and still over bottom substrates. They are usually found with their heads oriented against a mild current. As they maintain a benthic habit, their mouths are situated at the bottom of their heads. This position aids in its capture of water fleas, copepods, and insect larvae.
14) Longnose gar (Lepisosteus osseus)
Another seemingly primitive yet surprisingly well-evolved fish, the longnose gar has a distinctly elongated body. It retains a couple of the morphological adaptations of its ancestors; these include a specialized swim bladder allowing it to respire air, a spiral valve intestine, and tough scales for protection. Its markedly lengthy upper jaw is filled with sharp teeth – enhancing its voraciousness as an apex predator.
Iowa’s longnose gars are most concentrated in its bordering rivers, though some inland streams may also contain very small populations. The state record for this species was caught in the Missouri River in 2021. It weighed 22.2 pounds (10 kg). Though gars can measure as much as 6 feet (1.8 meters) long, they rarely exceed a length of about 4 feet (122 cm).
15) Smallmouth bass (Micropterus dolomieu)
Compared to the largemouth bass, the less popular smallmouth bass has a narrower distribution and is more sensitive to water conditions. This skilled swimmer thrives best in clear waters with high dissolved oxygen concentrations. Its colors and patterns can slightly vary depending on the properties of its environment. For example, water bodies with a sandy and bare substrate are associated with lighter-colored smallmouths. In contrast, habitats with vertical vegetation may house darkly speckled or striped individuals.
Most of Iowa’s smallmouth bass subpopulations are restricted to its northeastern streams, rivers, and lakes. As they maintain an omnivorous diet, they adjust their preferences based on the availability of fish, insects, and crustaceans. Their growth rate is significantly influenced by the food they consume as well as the water’s temperature. In Iowa, this species can grow to a trophy weight of 6 – 7 pounds (2.7 – 3.2 kg).
16) Creek chub (Semotilus atromaculatus)
Found in small streams all across Iowa, the creek chub has a knack for adapting to a wide range of environments and subsisting on different types of diets. This typically small fish favors the weedy and riffled zones of slow-moving pools. It can both feed and hide from predators in these areas, particularly those with holes in the substrate, exposed root systems, and submerged brush.
Able to grow to a full length of about 12 inches (30.5 cm), a mature creek chub can be a perfectly adequate catch for an amateur fisher. Smaller fish can be used as excellent bait for larger gamefish. Though sizeable specimens are not necessarily considered gamefish, they make for a fantastic source of high-quality proteins. These can also be caught using a minnow trap strategically placed in a small creek – at least one they are known to dominate – during the day.
17) Yellow perch (Perca flavescens)
Characteristically distinguished by its vertical black and yellow bars, the yellow perch is an eye-catching member of the Percidae family. Its subpopulations are most dense in shallow waters with submerged or emergent aquatic vegetation. In weedy microhabitats along shorelines, it can easily evade larger predators, create nests during its spawning period, and feed on macroinvertebrates.
Within their moderate lifespan of about 9 – 10 years, yellow perch can grow to a maximum length of about 20 inches (51 cm) and weigh as much as 4.2 pounds (2 kg). Nonetheless, fished specimens rarely ever reach half this size as they eventually become chum for gamefish in productive waters. The state record in Iowa was caught in a private lake, measuring 16 inches (41 cm) and weighing 2.7 pounds (1.2 kg).
18) Brown trout (Salmo trutta)
Brown trout is not native to Iowa, but it now has a few self-sustaining populations in the northeastern region of the state. Introduced into Iowa’s waters in the 1800s, this species quickly became a desirable gamefish. Though it is known to be a problematic, and at times invasive, fish in some parts of the US, it continues to be intentionally stocked to meet the demands of recreational fishers.
Hatchery-raised brown trout fingerlings are annually released by Iowa’s Department of Natural Resources (DNR) into selected, cold-water trout streams. In some of these streams, it is the sole stocked species. The hatchlings are able to grow at a rate of about 1 inch (2.5 cm) per month and reach maturity after about a year of growth. Trophy-sized specimens usually weigh around 3 pounds (1.4 kg) and will have lived in Iowa’s streams for at least 3 years.
19) Rainbow trout (Oncorhynchus mykiss)
As rainbow trout is a naturally anadromous species, its wild populations migrate between saltwater and freshwater environments to feed and spawn. It is thus a non-native fish in Iowa’s landlocked waterbodies. Like brown trout, it is intentionally stocked (from April to October) into cool streams by the DNR. There are currently no known self-sustaining populations of this species in the state.
Though rainbow trout can survive in fully enclosed freshwater habitats for quite some time, they appear to have some trouble expanding their range and reproducing in Iowa’s streams. This is due, in large part, to seasonal high temperatures. All hatchlings introduced into local waters are sourced from specialized trout hatcheries.
20) Shovelnose sturgeon (Scaphirhynchus platorhynchus)
The shovelnose sturgeon is a commercially important fish in the regions surrounding the Mississippi River. The smallest of North America’s sturgeons, it is the sole member of the Acipenseridae family that can be legally caught and harvested in Iowa for its flesh and highly valuable roe. It grows to a maximum length of about 3.3 feet (1 meter) and can weigh up to 12 pounds (5.4 kg) at maturity. The state record, which was captured in Des Moines River, weighed exactly 12 pounds!
This armored river fish is set apart from other sturgeons by its broad and slightly upturned snout. As suggested by its name, its snout bears resemblance to a small, pointed shovel. On the bottom of its protrusible mouth are four, hook-shaped barbels. These help it detect the presence of bottom-dwelling macroinvertebrates, such as insect larvae, small crustaceans, and mollusks.
21) Black bullhead (Ameiurus melas)
The black bullhead is distinguished from other common North American catfish by its square-shaped tail. This omnivorous species can consume practically anything organic in its freshwater environment. Able to live in turbid, low oxygen, and markedly warm waters, it has a knack for outcompeting many sensitive gamefish species. Outside of the US, its self-sustaining populations may spread at an invasive rate.
This hefty, olive green to black catfish is found in many of Iowa’s natural and artificial lakes and rivers, particularly those with slow-moving or still waters. It tends to congregate in pools or in depressions on the lake floor, where it may be protected from currents. Though it is not heavily sought by anglers, this “mud catfish” is known for being a flavorful delicacy.
22) Green sunfish (Lepomis cyanellus)
As hinted at by its common name, the green sunfish has a bluish-to-yellowish-green hue. Compared to other panfish species within the Centrarchidae family, it has a relatively large gape. Juveniles subsist on zooplankton and tiny insects. They eventually grow into carnivorous adults, able to consume smaller fish and crayfish. They tend to gather within stands of vertical vegetation in small, intermittently-flowing streams.
Schools of green sunfish can be found in practically all of Iowa’s freshwater systems. In these habitats, they serve as an important, self-sustaining source of nutrients for apex predators. During the spawning period, which typically lasts through June, their colonies may gather close to the shoreline to build their nests. Bluegills, which may hybridize with them, tend to share their nesting grounds.
