Sturgeons are among the most endangered animals globally. Once plentiful along the Atlantic coast, the shortnose sturgeon suffered severe population declines due to overfishing and habitat loss. In 1973, it was listed under the federal Endangered Species Act, as the Hudson River—its key habitat—was heavily polluted and oxygen-deprived.
Are sturgeon and catfish related?
No. Although sturgeon and catfish can be found in the same habitats and they both have barbels (whiskerlike growths extending from the jaw), they are not closely related. Sturgeon are much more primitive than catfish. There are some catfish sold for aquariums that look somewhat like sturgeon, and some fish have common names that are misleading (i.e. sturgeon chub) but these fish are not related to sturgeon.
Related
Are lamprey and hagfish related? Are lamprey and hagfish related?
Yes. Lamprey and hagfish are both jawless fishes. They are the only living members of the taxonomical class Agnatha (Greek for 'no jaws'). Learn more: Sea Lamprey Species Profile
Where can I find fish consumption advisories for my state? Where can I find fish consumption advisories for my state?
Most states have set fish (and wildlife) consumption advisories and recommended consumption levels. The state agency responsible for these limits varies. Examples of consumption advisory information can be found at the Environmental Protection Agency's Fish and Shellfish Advisories and Safe Eating Guidelines website.
What is the largest freshwater fish? What is the largest freshwater fish?
Sturgeon are the largest of the freshwater fish. The beluga sturgeon in Russia is the largest freshwater fish in the world. The white sturgeon is the largest freshwater fish in North America. White sturgeon have been reported to reach lengths of 15-20 feet and weights of nearly one ton. The second largest freshwater fish in North America is the alligator gar.
Shannon White Holding Shortnose Sturgeon
Sturgeons are among the most endangered animals globally. Once plentiful along the Atlantic coast, the shortnose sturgeon suffered severe population declines due to overfishing and habitat loss. In 1973, it was listed under the federal Endangered Species Act, as the Hudson River—its key habitat—was heavily polluted and oxygen-deprived.
Sharptooth walking catfish
Invasive species create risks to ecological communities. Recently, in Puerto Rico, sharptooth walking catfish (Clarias batrachus) were discovered as a new invasive species. This project is using environmental DNA (eDNA) to sample streams and help inform where physical removal efforts of this invasive species could best be allocated.
Invasive species create risks to ecological communities. Recently, in Puerto Rico, sharptooth walking catfish (Clarias batrachus) were discovered as a new invasive species. This project is using environmental DNA (eDNA) to sample streams and help inform where physical removal efforts of this invasive species could best be allocated.
Dr. Heather Walsh holding a blue catfish
Dr. Heather Walsh holds a blue catfish as part of sampling to determine PFAS levels in the fish.
Dr. Heather Walsh holds a blue catfish as part of sampling to determine PFAS levels in the fish.
Juvenile Lake Sturgeon
Juvenile lake sturgeon (Acipenser fulvescens) caught in a sea lamprey net in November 2023 in the Sturgeon River in northern Michigan. Photo credit: Ed Benzer, USGS.
Juvenile lake sturgeon (Acipenser fulvescens) caught in a sea lamprey net in November 2023 in the Sturgeon River in northern Michigan. Photo credit: Ed Benzer, USGS.
Flathead Catfish
Nebraska Cooperative Fish and Wildlife Research Unit - Nathan Gosch (right; master's student) utilizes a gastroscope to verify that all stomach contents were recovered from a flathead catfish held by Jeff Stittle (undergraduate).
Nebraska Cooperative Fish and Wildlife Research Unit - Nathan Gosch (right; master's student) utilizes a gastroscope to verify that all stomach contents were recovered from a flathead catfish held by Jeff Stittle (undergraduate).
Lake Sturgeon in Genesee River, NY
A USGS scientist holds a five-year-old stocked lake sturgeon recaptured during a survival assessment in the Genesee River, New York.
A USGS scientist holds a five-year-old stocked lake sturgeon recaptured during a survival assessment in the Genesee River, New York.
Pallid sturgeon
The Bureau of Reclamation (USBR) initiated a study on how its water operations influence fishes in the Missouri River basin above Fort Peck Reservoir. Of utmost concern is the effect of these operations on the spawning success and recruitment of endangered pallid sturgeon.
The Bureau of Reclamation (USBR) initiated a study on how its water operations influence fishes in the Missouri River basin above Fort Peck Reservoir. Of utmost concern is the effect of these operations on the spawning success and recruitment of endangered pallid sturgeon.
Huron-Erie Corridor Lake Sturgeon
Lake sturgeon collected on restored spawning grounds in the lower St. Clair River.
Lake sturgeon collected on restored spawning grounds in the lower St. Clair River.
Flathead Catfish
Biologist holding a flathead catfish caught by trammel net in the Lower Missouri River.
Biologist holding a flathead catfish caught by trammel net in the Lower Missouri River.
Related
Are lamprey and hagfish related? Are lamprey and hagfish related?
Yes. Lamprey and hagfish are both jawless fishes. They are the only living members of the taxonomical class Agnatha (Greek for 'no jaws'). Learn more: Sea Lamprey Species Profile
Where can I find fish consumption advisories for my state? Where can I find fish consumption advisories for my state?
Most states have set fish (and wildlife) consumption advisories and recommended consumption levels. The state agency responsible for these limits varies. Examples of consumption advisory information can be found at the Environmental Protection Agency's Fish and Shellfish Advisories and Safe Eating Guidelines website.
What is the largest freshwater fish? What is the largest freshwater fish?
Sturgeon are the largest of the freshwater fish. The beluga sturgeon in Russia is the largest freshwater fish in the world. The white sturgeon is the largest freshwater fish in North America. White sturgeon have been reported to reach lengths of 15-20 feet and weights of nearly one ton. The second largest freshwater fish in North America is the alligator gar.
Shannon White Holding Shortnose Sturgeon
Sturgeons are among the most endangered animals globally. Once plentiful along the Atlantic coast, the shortnose sturgeon suffered severe population declines due to overfishing and habitat loss. In 1973, it was listed under the federal Endangered Species Act, as the Hudson River—its key habitat—was heavily polluted and oxygen-deprived.
Sturgeons are among the most endangered animals globally. Once plentiful along the Atlantic coast, the shortnose sturgeon suffered severe population declines due to overfishing and habitat loss. In 1973, it was listed under the federal Endangered Species Act, as the Hudson River—its key habitat—was heavily polluted and oxygen-deprived.
Sharptooth walking catfish
Invasive species create risks to ecological communities. Recently, in Puerto Rico, sharptooth walking catfish (Clarias batrachus) were discovered as a new invasive species. This project is using environmental DNA (eDNA) to sample streams and help inform where physical removal efforts of this invasive species could best be allocated.
Invasive species create risks to ecological communities. Recently, in Puerto Rico, sharptooth walking catfish (Clarias batrachus) were discovered as a new invasive species. This project is using environmental DNA (eDNA) to sample streams and help inform where physical removal efforts of this invasive species could best be allocated.
Dr. Heather Walsh holding a blue catfish
Dr. Heather Walsh holds a blue catfish as part of sampling to determine PFAS levels in the fish.
Dr. Heather Walsh holds a blue catfish as part of sampling to determine PFAS levels in the fish.
Juvenile Lake Sturgeon
Juvenile lake sturgeon (Acipenser fulvescens) caught in a sea lamprey net in November 2023 in the Sturgeon River in northern Michigan. Photo credit: Ed Benzer, USGS.
Juvenile lake sturgeon (Acipenser fulvescens) caught in a sea lamprey net in November 2023 in the Sturgeon River in northern Michigan. Photo credit: Ed Benzer, USGS.
Flathead Catfish
Nebraska Cooperative Fish and Wildlife Research Unit - Nathan Gosch (right; master's student) utilizes a gastroscope to verify that all stomach contents were recovered from a flathead catfish held by Jeff Stittle (undergraduate).
Nebraska Cooperative Fish and Wildlife Research Unit - Nathan Gosch (right; master's student) utilizes a gastroscope to verify that all stomach contents were recovered from a flathead catfish held by Jeff Stittle (undergraduate).
Lake Sturgeon in Genesee River, NY
A USGS scientist holds a five-year-old stocked lake sturgeon recaptured during a survival assessment in the Genesee River, New York.
A USGS scientist holds a five-year-old stocked lake sturgeon recaptured during a survival assessment in the Genesee River, New York.
Pallid sturgeon
The Bureau of Reclamation (USBR) initiated a study on how its water operations influence fishes in the Missouri River basin above Fort Peck Reservoir. Of utmost concern is the effect of these operations on the spawning success and recruitment of endangered pallid sturgeon.
The Bureau of Reclamation (USBR) initiated a study on how its water operations influence fishes in the Missouri River basin above Fort Peck Reservoir. Of utmost concern is the effect of these operations on the spawning success and recruitment of endangered pallid sturgeon.
Huron-Erie Corridor Lake Sturgeon
Lake sturgeon collected on restored spawning grounds in the lower St. Clair River.
Lake sturgeon collected on restored spawning grounds in the lower St. Clair River.
Flathead Catfish
Biologist holding a flathead catfish caught by trammel net in the Lower Missouri River.
Biologist holding a flathead catfish caught by trammel net in the Lower Missouri River.
Updated Date: March 12, 2026