Sturgeon (family Acipenseridae)

FishLiving fossilFreshwater

Overview

Sturgeons (family Acipenseridae) are ancient, large, and unmistakable fish that have changed remarkably little since the time of the dinosaurs, earning them the label “living fossils.” Instead of ordinary scales, they have rows of bony plates (scutes) running along the body like armour, a long shovel-like snout with whisker-like barbels underneath, a toothless protrusible mouth, and a shark-like tail. The lake sturgeon (Acipenser fulvescens) is shown here.

Sturgeons are slow-growing, late-maturing, and very long-lived — some live well over a century — and several rank among the largest freshwater fish in the world.

Conservation note: sturgeons are among the most threatened groups of animals on Earth, heavily affected by overfishing (especially for caviar), dams, and habitat loss. Verify each species' status at iucnredlist.org.

Habitat & Range

Sturgeons live across the Northern Hemisphere — in rivers, lakes, and coastal seas of North America, Europe, and Asia. Many are anadromous, living in the sea or large lakes and migrating up rivers to spawn, while others stay in fresh water all their lives. They are bottom-dwellers, needing clean rivers with suitable gravel beds for spawning.

Diet

Sturgeons are bottom-feeders. They cruise along the riverbed or seafloor, using the sensitive barbels under the snout to detect prey, then extend their tube-like, toothless mouth to suck up food — mainly invertebrates such as insect larvae, worms, molluscs, and crustaceans, plus small fish in some larger species. They feed by suction rather than biting.

Behavior

Sturgeons are generally slow-moving and long-lived, growing throughout much of their lives and not breeding until they are many years old — sometimes decades. They make long spawning migrations up rivers, and females may release enormous numbers of eggs, though they spawn only every few years. Some sturgeons are famous for leaping clear out of the water, a striking and not fully explained behaviour. Their slow, late reproduction makes populations very slow to recover from losses.

Human Interaction & Conservation

Sturgeons have been prized for centuries for their flesh and especially their roe, sold as caviar — a value that has driven catastrophic overfishing and poaching. Combined with dams that block their spawning migrations and the loss of clean river habitat, this has pushed most sturgeon species into serious decline, making them a conservation priority worldwide. Sustainable, legal sourcing and habitat protection are essential. Consult the IUCN Red List for species-specific status.

More photos of the sturgeon