Located in the beautiful Dane County of Wisconsin, Lake Mendota is a popular lake for recreationists of all sorts! It contains public boat landings, and public beaches for locals and out of towners to enjoy. People come from near and far for fishing, boating, and beachgoing in the summer, and even ice skating and ice fishing in the winter! This incredible lake can be enjoyed year-round by all who choose to visit.
Encompassing an area of over 15 square miles, Lake Mendota is a fairly large lake offering over 25 miles of shoreline. An average depth of 42 feet (and a maximum depth of 83 feet!) means that this lake can hold many different fish species, from shore-loving bluegill to massive sturgeon in the deeper waters.
Anglers visit Lake Mendota from near and far to fish the fecund Wisconsin waters. With 9,781 acres, the lake has a great variety of species. While there are many species of fish that call this lake home, the most sought-after species by anglers include bluegill sunfish, largemouth bass, smallmouth bass, northern pike, walleye, lake sturgeon, channel catfish, and several others including muskellunge. While identifying fish by species may seem like a daunting task, it can be easily done if you know what features to look out for!
For a detailed list of fishable species in Lake Mendota and size and bag limits, check out the Wisconsin DNR’s fishing regulations page for Lake Mendota here.
Fish Species in Lake Mendota
1) Bluegill sunfish (Lepomis macrochirus)
Bluegill are abundantly found and native to freshwater systems all across North America. They are a popular catch among anglers and are often called “bream,” “brim,” or “sunnies” rather than bluegill. These pretty fish can be best identified by their beautiful iridescent coloration and deep-bodied shape.
Bluegill grow to be around 7.5 inches in length (19.1 centimeters) on average, but they can grow to be up to 12 inches long (30 centimeters)! While coloration can vary slightly between populations, they tend to have a deep blue or green color. These fish have a deep and highly compressed body shape. They are sometimes even called “panfish” by anglers because mature individuals are about the size and shape of a pan!
Bluegill will eat a variety of food. They are what we call opportunistic feeders, which means exactly what it sounds like! They will eat whatever is available and accessible in the environment, whenever the opportunity arises. The bluegill diet typically consists of a variety of insects, worms, crustaceans, and larvae.
Spawning and reproduction for the bluegill sunfish usually occur around the months of May and August. They are very prolific spawners – a single female can spawn three times in a season and she will release anywhere from 2,300 – 81,000 eggs per spawning event! The male bluegill builds the nest in which the female lays her eggs. After she lays her eggs, the male will come by to fertilize them, and he will stick around to defend them until they hatch.
2) Largemouth bass (Micropterus salmoides)
The largemouth bass is a very popular species among sport-fishers. As adults, mature largemouth bass can be around 30 inches in length (76 centimeters). Largemouth bass have relatively long lifespans, and can live for 25 years naturally!
When it comes to appearance, largemouth bass can be identified by their elongated body, and dark green and yellow coloration. They have a dark horizontal stripe adorning the side of the body, and, as the name suggests, they can often be distinguished from closely related species by the size of their mouths!
Although largemouth bass are carnivorous throughout their lives, their dietary preferences evolve as they get older. When they are young, M. salmoides eat mostly insects, zooplankton, and smaller fish. As they mature and grow in size, their diet shifts and they begin to feed on larger insects, crayfish, and even other fish species.
Like most other species of fish, largemouth bass spawn in the springtime. Males will build nests in shallow waters, preferably on top of gravel or sand substrate. Females deposit eggs in these nests, and the males will come along later and fertilize them. The fertilized eggs will develop and hatch in just about a week! The males will stick around in order to protect their school of larvae for the first month – until they are large and hardy enough to have a higher survival rate.
3) Smallmouth bass (Micropterus dolomieu)
Smallmouth bass typically grow to be anywhere from 12 to 16 inches (30 – 40 centimeters) in length. Within freshwater lakes, they tend to inhabit the more shallow, rocky areas along the shoreline. Rocks and vegetation afford them cover for feeding and protection. They can be similar in appearance to the closely related largemouth bass, but largemouth have a single horizontal dark stripe along their sides that smallmouth lack. Smallmouth bass can be distinguished by the multiple vertically-oriented stripes that run along its body.
Young, immature smallmouth bass usually tend to feed on plankton and small insects. As they mature into adults, they begin to feed on crayfish, insects, and even other fish. Some smallmouth bass are cannibalistic, and have been seen eating other smallmouth bass!
During the mating season, a male smallmouth bass will build a spawning nest in shallow waters, among the bottom substrate. Above the nest, a mating pair will perform a unique spawning ritual. Eggs are then fertilized, and they will hatch within about 6 days. Male smallmouth bass will guard the nest until the fry are hardy enough to live and survive in the world on their own!
4) Northern pike (Esox lucius)
Northern pike are widely found in bodies of freshwater all across the Northern Hemisphere. They are pretty easy to identify – they have characteristic long, slender bodies and olive-green coloration. These large fish have light-colored spots on their sides, and a unique, long, flattened snout. These fish have a mouth full of razor-sharp teeth, which allows them to prey on basically anything that moves! They grow to be very large and can range in length from 18 – 20 inches (46 – 51 centimeters).
E. lucius can thrive in streams, lakes, and large rivers. They tend to hang out in areas that have dense vegetation, which helps them hunt prey. If you enjoy fishing for northern pike, it’s a good practice to cast near the shoreline around rocky or densely vegetated spots.
Pike are well-known for their aggressive demeanor and carnivorous tendencies, and they eat a whole lot of food each day. While northern pike prefer to prey on other fish species, they have also been known to eat frogs, mammals, and waterfowl! These huge predatory fish hide under cover until prey comes along, and then they strike to catch it.
When it comes to spawning, northern pike are “broadcasters”. Females will release eggs over vegetation, and one or more males will come along and fertilize them from above. They typically spawn in shallow waters during the springtime.
5) Walleye (Sander vitreus)
The walleye is a species of freshwater fish that is named after its large, opaque, silvery eyes! The species belongs to the perch family, Percidae. They are a popular sport fish, and are widely and commonly stocked in rivers and lakes. These fish can grow to be 2.5 – 3 feet (0.75 – 0.9 meters) and weigh up to 10 – 20 pounds (4.5 – 9 kilograms)! They are long and thinly shaped, with golden-olive coloration. They also can be distinguished by their dorsal fins; one is spiny and the other is soft-rayed. Walleye have dark spots patterning their backs, and razor-sharp teeth to hunt with!
Named after its characteristically unique eyes, the walleye has a thin and reflective ocular film that allows it to hunt very well during the night hours and in murky water! They are nocturnal hunters and prey on small fish, invertebrates, and insects.
In a single spawning event, a female walleye will move to shallow, warm waters to release up to 500,000 eggs! After becoming fertilized by a male, the eggs will hatch in about 10 days.
6) Lake sturgeon (Acipenser fulvescens)
Lake sturgeon, or “rock sturgeon,” are a very long-lived and interesting fish! They can be found in rivers and lakes across North America, but unfortunately, the species has been declining in recent years due to a combination of overharvesting and the species’ natural history and spawning habits. This particular species should not be confused with any of a number of smaller (though still large!) sturgeon species. In Lake Mendota, it is not legal to catch lake sturgeon, not even for catch and release.
Lake sturgeon are easy to identify. They can be huge, growing up to 6.5 feet (2 meters) in length and weighing up to 200 pounds (90 kilograms)! They look shark-like and prehistoric in appearance – sturgeon fossils have been dated back to the Late Cretaceous period. Despite their appearance, sturgeon are gentle giants and pose no threat to humans. Females have been known to live for 150 years, and males may live up to 55 years of age. Lake sturgeon lack scales, but instead they have coarse, rough skin and bony plates along the back and sides.
As omnivorous fish, lake sturgeon feed a variety of food including insect larvae, crayfish, snails, clams, and leeches. They have barbels located near their mouth to help them locate food.
While a female sturgeon may lay anywhere from two to three million eggs in a single spawning season, they do not reach reproductive maturity until 15 – 25 years of age. On average, a reproductive female will only spawn approximately every four years.
7) Channel catfish (Ictalurus punctatus)
Channel catfish are known by a variety of common names. You may have heard them referred to as “fork-tailed cat,” “fiddler,” “spotted cat,” or “lady cat.” One of the most popular game fish species in North America, channel catfish are named for their distinctive whiskers, or “barbells,” that enable them to locate food in dark, murky water. Shockingly, they can live up to 15 – 20 years!
When it comes to identifying these guys, it may be tricky to tell them apart from other catfish species. Channel catfish are light blue or greyish in color, and their smooth and scaleless bodies set them apart from other species of fish. They have flat broadly shaped heads, slender bodies, and forked tails like other catfish species. They’re also the most sought-after species of catfish amongst anglers in the US!
I. punctatus have a very strong sense of smell and taste, and they even have taste buds that cover the surface of their bodies! They prey on small fish, crustaceans, insects, clams, and snails, and have a taste for small mammals or birds when the opportunity arises.
Channel catfish are a monogamous fish species – they will stick with one mate throughout a spawning season. They are cavity nesters, and a female will lay between 3,000 and 50,000 eggs in the nest crevice during the springtime months when the water temperature gets warmer.
8) Muskellunge (Esox masquinongy)
The muskellunge is the largest fish in the Esocidae family, often known simply as the “muskie.” Closely related to the northern pike, they look rather similar with their long and lean bodies and sharp teeth. As a gregarious ambush predator, the adults have little to fear and most to gain in the position of an apex predator. Apart from humans, only large predatory birds such as the bald eagle pose a threat to a fully grown muskie. They’re notoriously difficult to catch, sometimes called “the fish of a thousand casts,” as they will follow your lure and toy with it without actually biting down on it, sometimes even coming up to the boat.
The muskie typically spawns towards the end of May. The female deposits her eggs over aquatic vegetation, while the male releases his milt to fertilize them. In contrast to the northern pike, the muskellunge is a fractional spawner, meaning that the female produces two clutches of eggs. It is of great importance to protect known spawning sites of the muskellunge since it displays a behavior known as reproductive homing. Such species return to their own hatching site to spawn when they become sexually mature.
9) Black Bullhead Catfish (Ameiurus melas)
Despite being related to them, black bullhead catfish dwarf channel catfish at an average of one to two lbs. The small fish have scaleless dark brown or black bodies with pale yellow or white underbellies. They can be easily recognized by their black barbels, notably flat head, and tan crescent before their square tail fins. Like channel catfish, bullheads thrive in poor water conditions. They prefer slow-moving water and can easily survive in murky, poorly oxygenated waters.
Black bullheads are omnivorous bottom feeders with a widely varied diet including algae and crustaceans. They feed nocturnally most of the year, but during the winter they have a lessened appetite and may temporarily stop eating altogether.
Black bullheads have a relatively short lifespan at only six to eight years in the wild, and it takes approximately half of their life to reach sexual maturity. This timespan means that it is critical for black bullhead fry to survive to adulthood. Unlike many species of catfish that only have the male playing a parental figure, both males and female black bullheads play an important role in raising their young. After spawning in the spring, both parents take turns guarding their eggs. Even after hatching, fry are closely protected by their parents, who will circle around them for about two weeks until they are able to be on their own.
10) Pumpkinseed (Lepomis gibbosus)
Closely related to bluegill, the pumpkinseed is a deep-bodied, small-mouthed fish in the sunfish family. They are brightly colored and distinguishable by a small red spot near the edge of their operculum, which does not have a spike. The first spiny dorsal fin extends into the second soft dorsal fin, so the two fins visually become one.
The native range of the pumpkinseed extends farther north than any other fish species belonging to the Lepomis genus in the sunfish family. They are colony nesters, with as many as 15 shallow, oval-shaped nests in a single colony. The female arrives after the males have built their nests, deposits her eggs which stick to the bottom, and leaves the male to guard the eggs and hatchlings. For the first 11 days, the males keep a close eye and have even been observed to return with straying hatchlings in their mouths.
11) Common Carp (Cyprinus carpio)
An incredibly large and hardy minnow, common carp were introduced as farming and sport fish around the world in the 1880s. Unfortunately, they have since then become regarded as a nuisance due to their invasive and destructive tendencies in local ecosystems. They often uproot aquatic plants while feeding, consequently muddying the waters they live in. It’s no wonder common carp are able to wreak havoc — the heavy-bodied fish can thrive in almost any condition and can spawn 300,000 eggs multiple times a year. Additionally, they can get incredibly large, regularly reaching a whopping 75 lbs. In Wisconsin, the largest carp ever caught 46 inches long and exactly 59 pounds!
Common, or Eurasian, carp often move between Lake Mendota and the Cherokee freshwater estuary depending on the time of year. They seem to move into the estuary in the fall and remain in its deepest portions throughout the winter, moving to Lake Mendota in the spring and largely remaining there until the autumn, though not all tracked carp engaged in this pattern.
Common carp are an often invasive and nuisance species in the U.S. as they hail from Eurasian regions. However, they make a tasty dish and can be difficult to catch, which adds to the appeal for anglers. In Wisconsin, fishing of common carp is encouraged to help control their numbers. Common carp can be distinguished from other members of its genus by the two pairs of barbells on their upper jaws. They have large scales and a relatively uniform coloration but can be green, yellow, brown, or silver. Common carp are closely related to koi and similarly long-lived, living upwards of 40 years.
12) Longnose Gar (Lepisosteus osseus)
Longnose gar are solitary creatures and are typically only found in groups during the spawning season (spring and summer months), though they are considered uncommon in Lake Mendota. Gar play an important ecological role; because of their role as top predators, they are critical to reducing overpopulation in forage fish. While gar meat is consumed by humans, their eggs are extremely toxic.
Longnose gar can be identified by their elongated snouts which are more than twice the length of their heads. They have built-in armor via their interlocked, rhomboid, ganoid scales. A unique fact about longnose gar is that they can survive indefinitely with aerial oxygen only. This is because they have highly vascularized swimbladders and can close their gills in low oxygen levels.
13) Yellow bass (Morone mississippiensis)
Though yellow bass are native to Lake Mendota, they are not incredibly common in this lake. These fish prefer to live in the quiet pools and backwaters of rivers and lakes rather than lakes. They grow to an average length of 9 in (24 cm). As their name suggests, the sides and underside of yellow bass are yellow or pale cream in coloration.
Younger yellow bass feed mostly on smaller crustaceans and insects, and adults primarily eat other fish. Like smallmouth bass, yellow bass are also known to be cannibalistic by nature! They are invertivores and carnivores that tend to feed mid-water and near the surface.
Yellow bass reach sexual maturity between 2 and 4 years of age, and spawn between the months of April and June when water temperatures have increased power-winter. Females release their eggs in multiple clutches, and her eggs from each spawning are fertilized by more than one male.
14) White bass (Morone chrysops)
White bass belong to the same family that houses striped bass, yellow bass, and white perch. It’s distinguishable from other bass found in Lake Michigan by its light coloration, ranging from dark grey along its back and gradually lightening to silvery-white or white on its belly. It also has several rows of horizontal bars of contrasting brown-grey, greenish, or dark grey scales along its sides. White bass possess two dorsal fins; the first, closest to the head, is spiny, while the second appears more smooth and lacks spines. Their average length is around 1 foot, but the largest white bass recorded was over 17 inches long.
Preferring open waters, white bass can often be found chasing schools of shad as the latter group together to migrate. During spawning season, which typically begins around May for white bass in northern regions like Lake Michigan, expect to find them in tributaries like rivers and streams, or on rocky shoals along the banks or sandbars. They dislike overly vegetated areas and muddy or turbid waters. In Lake Mendota, they are a pelagic species, meaning that they are found toward the middle of the water rather than near the surface of the bottom, with many being caught around 6 meters below the water’s surface.
Their diet primarily consists of shad (their favorite food) and other fish like small sunfish and silversides, but can also include zooplankton, crustaceans, worms, and aquatic insect larvae and adults, such as stoneflies, midges, and mayflies. They are entirely carnivorous and do not eat vegetation.
