Anglers and non-anglers alike balk at the sight of a massive fish. Usually, enormous fish species are found in the ocean; some examples include the goliath grouper (Epinephelus itajara) or the bluefin tuna (Thunnus thynnus), but there are also behemoths lurking in North American freshwater lakes, rivers, and reservoirs.
Many of the largest freshwater fish species, such as lake sturgeon, can be found in large lakes. Examples include the Great Lakes in North America which are known for supporting impressive fish species. Rivers like the Mississippi River and Missouri River are also home to some of the largest freshwater fish species.
Artificial reservoirs created by damming rivers can harbor large fish species—reservoirs such as Lake Mead in the United States and Lake Volta in Ghana are two examples of large reservoirs that support large fish populations. Although reservoirs can also impact populations of fish that require continuous river habitats. Lastly, wetlands and swamps, such as the Florida Everglades and southern Louisiana make great homes for large gar.
1) White sturgeon (Acipenser transmontanus)
History & Conservation Status
The record size of a white sturgeon caught in the modern day is around 11 feet (3.4 meters). Ancient records report individuals reaching lengths of up to 20 feet (6.1 meters) and weighing over 1,500 pounds (680 kilograms). These humongous sizes are unheard of in the modern day due to habitat fragmentation and overharvesting of sturgeon.
In the mid to late 1800s, white sturgeons were prized for their caviar, and the lucrative fishery led to the endangerment of the species. While their populations have recovered since due to federal regulations and management, it remains vulnerable to extinction, according to the IUCN.
Diet, Habitat, & Ecology
The white sturgeon’s range extends from Alaska to central California along the North American Pacific Coast. They occupy large rivers, lakes, and reservoirs with enough detritus, space, and food for them to thrive. Occasionally, they can be found in marine environments as well. Estuaries of large rivers are the preferred habitat for white sturgeon.
A diet of small invertebrates, clams, crustaceans, and occasionally fish supports these massive fish and allows them to grow to monstrous sizes. Huge individuals are so big that they practically have no predators besides humans and can live to be over 100 years old. At approximately 10 – 16 years old, white sturgeon begin migrating upstream to spawning grounds to reproduce, and females can produce hundreds of thousands, possibly even millions of eggs each season.
Fishing for White Sturgeon
The Fraser River in Canada is one of the best locations to fish for white sturgeon, producing record-setting sturgeons for over a decade. Most white sturgeon fishing programs are catch-and-release only, although some states, like California, allow the taking of white sturgeon for meat following specific guidelines and regulations found here.
2) Lake sturgeon (Acipenser fulvescens)
History & Conservation Status
Historically, lake sturgeon populations were widespread throughout the Great Lakes and their associated river systems. They were also present in major rivers such as the Mississippi River and its tributaries, the Missouri River, and the St. Lawrence River. However, due to overfishing, habitat degradation, and other factors, lake sturgeon populations have declined significantly. Currently, efforts are being made to restore and conserve these fish populations. As a result, specific locations where the largest lake sturgeon can be found may vary depending on the success of conservation initiatives and the status of local populations.
Diet, Habitat, & Ecology
Using its peculiar-looking barbels on the bottom of its chin, the sturgeon rummages around in the substrate for all aquatic invertebrates like clams, aquatic insects, crabs, and more. Other aspects of their ecology and habitat are like the white sturgeon, although lake sturgeon spend more time in the depths of large lakes and rivers than in estuaries with sea access.
Fishing for Lake Sturgeon
As bottom dwellers, sturgeon are best targeted using sinking baits that can lie on or near the bottom of the water column. They will most readily accept baits like their natural diet, such as crabs or mollusks. Additionally, sturgeon are an imperiled species and are usually highly regulated. Most states, like Wisconsin, have limited harvest seasons for sturgeon and require the purchase of a tag to harvest this species.
3) Alligator gar (Atractosteus spatula)
History & Conservation Status
Like many long-lived giants, the alligator gar was once abundant through the Mississippi River and its larger tributaries. However, as North America was transformed during the industrial era, leading to the construction of dams and levees that altered the river’s flow and blocked access to spawning sites, alligator gar populations suffered.
Additionally, more intentional efforts to eradicate gar have historically been employed due to the misconception that gar eat sportfish. While this is true to an extent, they do not exclusively predate upon popular sportfish and, instead, opportunistically hunt whatever may be available. Currently, alligator gar populations are doing well, and conservation efforts aim to preserve their role in the ecosystem and encourage the sustainable harvest of this species.
Diet, Habitat, & Ecology
The largest gar species is the alligator gar. In addition, it is long-lived, capable of living longer than 50 years. Alligator gar are generalist carnivores known to eat crabs, turtles, birds, and small mammals, making them important apex predators in most fish communities. They are easy to identify compared to other gar species given their blunt and broad snout. Luckily, they only co-occur with slender gar species, which have thinner snouts and smaller body sizes, making identification relatively easy. Alligator gar primarily occur in freshwater wetlands and are sometimes known to hunt in saltier coastal or marine environments.
Fishing for Alligator Gar
Since alligator gars are predators, the best bait to use for this species is live fish like small carp, sunfish, and any other small bait species that may be living in the same waterway as gar. Bait is usually intended for rod and reel fishing, but there are other popular methods to hunt alligator gar, most notably bow fishing. Bow fishing involves using a bow and arrow to hunt down giant alligator gars. Thrill-seekers will pay thousands of dollars for guided tours to fish for gar using a bow and arrow. It is important to note that since bow fishing is a lethal method of hunting alligator gar, it is regulated differently, usually more strictly, than rod and reel fishing. Always consult local wildlife agencies for the current fishing guidelines to help preserve the future of these species.
4) Blue catfish (Ictalurus furcatus)
History & Conservation Status
Blue catfish are one of North America’s most popular sport fishes. As a result, it is no surprise that people want them stocked in sport fishing lakes and reservoirs, leading to their introduction to regions of the United States far outside of their native range. They have established breeding populations in these regions, ensuring that they are there to stay. In these new ranges, they consume native species and are considered invasive in some areas, like the Chesapeake Bay in New England. Additionally, in regions where they are introduced to Mexico, they hybridize with the Yaqui catfish (I. pricei), an endangered species.
Diet, Habitat, & Ecology
Like the alligator gar, blue catfish are generalists who eat anything they can find on the bottom of any lake or river they inhabit. Some prey items include small fish, mollusks, invertebrates, and plants. They tend to occupy the deepest parts of lakes and sluggish rivers, preferring areas with hard substrates like gravel or rock. Despite these preferences, they are incredibly hardy and can survive in diverse habitats.
Fishing for Blue Catfish
An angler should look for the deep holes and crevices they hide in to fish for catfish. Forage species, like shad or small sunfish readily available in the local ecosystem, are the best option for bait. Blue catfish use their barbels to smell prey in the water, so the smellier the bait, the better. Allow your bait to sink to the bottom and wait for a catfish to bite. They are also known to accept crankbaits.
5) Flathead catfish (Pylodictis olivaris)
History & Conservation Status
Flathead catfish were an important food source for indigenous Americans and European settlers. Their populations are generally stable and, for reasons nearly identical to the blue catfish, they have been intentionally introduced outside of their range to improve the quality of sportfishing in lakes and reservoirs throughout the United States. Where introduced, they feed on native prey species and small sunfish and, in some cases, can be a nuisance for conservation efforts by causing the decline of native prey species.
Diet, Habitat, & Ecology
Like the blue catfish, this species prefers deep pools of large rivers, lakes, and reservoirs. Here, they hide amongst submerged debris and wait to ambush prey items. Compared to the generalist blue catfish, the flathead catfish is a strict carnivore that feeds on smaller fish and aquatic invertebrates.
Fishing for Flathead Catfish
When fishing for flathead catfish, anglers should target deep, sluggish pools. Flathead catfishes are notorious for hanging around the depths of reservoir dams, but they are also readily found amongst submerged debris like logs or large stones. An angler will have better luck pursuing this species during the summer, especially in colder climates. They accept various artificial and natural baits, but locally sourced bait fish is the easiest and most effective option.
6) Mississippi paddlefish (Polyodon spathula)
History & Conservation Status
Paddlefish are among the most endangered fish groups on the planet, with only two species alive in the modern era. Unfortunately, the only living relative of the Mississippi paddlefish went extinct in 2022 following the construction of dams along the Yangtze River in China, making the Mississippi paddlefish the only surviving member of the paddlefish family. The Mississippi paddlefish is found only in the Mississippi River and the Great Lakes and is considered vulnerable by the IUCN Red List in some of its ranges.
As with the Chinese paddlefish, the primary threats to the Mississippi paddlefish are the construction of dams along its migration routes and the alteration of native habitats. Due to their long rostrum, they are also easily captured as bycatch in nets designed for other fisheries, resulting in increased mortality rates.
Diet, Habitat, & Ecology
Paddlefish are long-lived fish with a maximum life span of 30 years and can max out at 7 feet (2.1 meters) long. Since they are a long-lived species, paddlefish infrequently spawn only once every two to three years, producing thousands of tiny offspring while investing little parental care. They primarily occupy large, continuous rivers.
Fishing for Mississippi Paddlefish
Given the rarity of paddlefish and serious conservation concerns surrounding this species, its harvest is strictly regulated, and anglers should adhere closely to local fishing regulations. For example, populations in Louisiana are stable, so the regulated harvest of paddlefish is allowed, but there are some restrictions. In Texas, individuals may harvest up to 5 paddlefish, and only two may be less than 16 inches (41 cm) long. Each state has its own regulations regarding the harvest of paddlefish, so be sure to check with state wildlife officials.
7) Chinook salmon (Oncorhynchus tshawytscha)
History & Conservation Status
In some areas, Chinook salmon have been intentionally introduced as a sportfish and are known to compete with native trout species. Conversely, Chinook are classified as endangered in their native range and are protected by the U.S. Fish and Wildlife Service. Population declines for this species are attributed to overharvesting and the construction of dams along their migration routes resulting in habitat loss and destruction.
Diet, Habitat, & Ecology
The Chinook salmon is native to cold waters on the Alaskan coast, with a range extending south to Monterey Bay, California, and westward into coastal Siberia and Japan. This species is anadromous, meaning their young are born in freshwater streams, slowly migrate to the ocean, and then return to their natal streams to reproduce. Once they arrive at the appropriate spawning grounds, females dig nests or redds into the substrate and lay their eggs. After this spawning event, the adults die.
Fishing for Chinook Salmon
The Chinook’s large size has earned them the title of “king,” and as such, they are commonly referred to as ‘king salmon’. So, it’s no surprise that anglers want to catch some! Anglers usually use salmon eggs as bait and techniques like plunking, trolling, and drift fishing to entice salmon to bite. In some areas, it is illegal to harvest Chinook salmon, so it is important to be aware of local regulations to avoid hefty fines and to preserve these salmon for future generations.
Young Chinooks can be found in rivers as they go to the ocean. Older individuals are found in coastal waters, and adults can be found on their way back to spawning grounds during the breeding season from late summer to early winter.
Fishing Considerations – Can You Catch One?
That depends on the species and fishing location. Many monster fish species require a great deal of patience, know-how, and strength to reel in a record-breaking contender, and, in some cases, luck is just as important.
Unfortunately, several of these species, like gar and sturgeon, are late-reproducing, slow-growing species that require long periods to reproduce and, as a result, have become rare due to overharvesting and overfishing. Additionally, many large fish species are highly migratory, and the construction of dams and reservoirs in the 1900s has fragmented their habitats, preventing adults from reaching spawning grounds and reducing overall populations. This is one reason that record-setting catches of massive fish species occurred in the 1900s, and few contenders are caught today.
Motivated by conservation concerns and to improve the fishing quality of North American waters for human recreation, government agencies like the U.S. Fish and Wildlife Service have implemented harvest regulations for rare species. Anglers should know local, state, and federal laws regarding their target species to avoid stiff penalties and fines.
Note: Record catch data in this article was retrieved from http://www.fishing-worldrecords.com/ and may change since this article’s publication.
