Sturgeon

Sturgeons are famed for their long lifespan, with some individuals living for over a century. They are also well known for their eggs, which are sold as the delicacy called caviar.

Sturgeons are an ancient group of fish, extending back in the fossil record for over 100 million years, to the Cretaceous Period. The tribe today combines the beluga, which is the most substantial freshwater fish in the world. Although it grows up to 28 feet in length, it is a fish that is not often seen. Instead, the beluga hides away, remaining close to the river bottom, where it digs in the sediment in search of food such as worms. The white sturgeon, that can grow to about 20 feet, is the largest of North America’s freshwater fish.

Body Make-up

Unusually, sturgeons have skeletons made of cartilage (gristle) instead of bone. Unlike many fish, their backbone also extends into the upper part of their tail. One of the more obvious features of sturgeons is the presence of five rows of bony plates, called scutes, that run along each side of the body. 

They also have structures called gill rakers that enable them to filter food particles from the water as it passes over the gills located on each side of the head. Their mouth is on the underside of the body, and can form a sucking tube. There are four sensitive barbels, or feelers, surrounding the mouth. Adult sturgeons have no teeth in their jaws.