STURGEON FISH

This is an ancient group of Late Cretaceous fish with primitive features that indicate a long evolutionary record. This fish most likely descended in Jurassic time from acipenseriform fish, but there is no agreement in the literature as to exactly when sturgeon fish first appeared in the fossil record. Their geologic time range is estimated to be Late Cretaceous (possibly about 70 million years ago) to Recent.

Some Interesting Facts

Sturgeons are scaleless and their skeletons are cartilaginous. Based on these observations, early workers wrongly assumed that sturgeon fish are sharks. Some sturgeon fish species have smooth skin, whereas other species have rows of bony scutes. The presence of bony scutes readily distinguishes them from sharks.

Some species of sturgeons can live in fresh water (rivers and lakes) and, for at least parts of their life span they can also live in shallow-water saltwater (gulfs). They are bottom feeders. A few species suck up their food off the bottom via a quick-acting “suction pump.”

Sturgeons are native to subtropical, temperate, and sub-arctic rivers, lakes, and coastlines. They are a Northern Hemisphere fish, with several species in the U.S.A. and Europe. For example, they live in the Columbia and Sacramento river systems of the Pacific Northwest of the USA. Like salmon fish, sturgeons live in salty water but return to fresh water for spawning. Some species are exclusively fresh water, whereas other species are primarily marine inhabitants. Also, like the salmon fish, they migrate upstream but, unlike salmon, do not die after spawning. Sturgeons feed on the salmon fish.

They can live 100 years + and can be up to 7.2 m (23 feet, 7 inches) long. Sturgeons do not start reproducing until they are 15-33 years old. Some sturgeon species weight up 3,500 pounds (male). They are very strong, especially their tails. Thus, they can swim long distances up large, powerful rivers. 

There are five living genera and 26 or 27 living species. There are four categories of these species: vulnerable, endangered, or critically endangered. A few of these species however are farm-raised (for their meat and cavier (eggs).

Classification

Kingdom Animalia

Phylum Chordata

Class Actinopterygii

Order Acipenseriformes

Family Acipenseide 

Genus Huso

Type species: Huso huso

Among the living species of sturgeons, 10 are raised for their caviar and meat. The other species are either endangered or critically endangered, with some species now being federally protected.

Figure 1. Side view of Acipenser medirostris, also known as the “Green Sturgeon.” My sketch was based on a photographic image of a live specimen found in a river environment. The photograph was taken by Laura Heironimus, of the Washington Department of Fish and Wildlife, and used in December, 2021 by Wikipedia. Length of this specimen not given, but it was probably several feet long. 

Reference

Nordhaus, H. 2025.  Surviors from the “Dinosaur Age.” National Geographic Magazine, April 2025, pp. 115-133.

Wikipedia. 2025.