Body shape and skin
Elongated, spindle‑like body that is smooth and scaleless, armored with five lateral rows of bony scutes.
Sturgeon
Sturgeon are large, long‑lived, scaleless fishes with bony scutes, found in rivers, lakes, estuaries and coastal waters across Eurasia and North America.
Acipenseridaesturgeons
Last Updated Mar 9, 2026 · 2 sources
Species Guide
What to know about sturgeons
A clean field guide focused on habitat, identification, behavior, and conservation context without burying the useful parts.
“Sturgeon” refers to 27 species in the family Acipenseridae, grouped into five genera (Acipenser, Huso, Scaphirhynchus, Sinosturio and Pseudoscaphirhynchus). They are one of two living families of Acipenseriformes alongside paddlefish. Sturgeons have ancient origins, with sturgeon fossils known from the Late Cretaceous and acipenseriform relatives dating back to the Early Jurassic. Typical features include an elongated, spindle‑like body, smooth, scaleless skin armored by five lateral rows of bony plates called scutes, and a heterocercal caudal fin. Several species reach large sizes (commonly 2–3.5 m / 7–12 ft), and some individuals have been recorded much larger. Many sturgeons are anadromous bottom‑feeders that migrate upstream to spawn and spend much of their lives feeding in river deltas and estuaries; other species are exclusively freshwater or primarily marine and may venture into the open ocean. Several species are harvested for their roe (processed as caviar), and widespread overexploitation combined with other conservation threats has brought most species to critically endangered status.
Widespread overexploitation for roe, combined with other conservation threats, has resulted in severe declines and critical endangerment for most sturgeon species.
Many sturgeon are anadromous bottom‑feeders that migrate upstream to spawn and spend much of their lives feeding in river deltas and estuaries; some species are exclusively freshwater, while others primarily inhabit marine coastal areas and may venture into the open ocean.
Identification
How to identify sturgeons
The visual markers divers can use underwater, plus the species most likely to cause confusion.
Key identification markers
Tail
Heterocercal caudal fin (upper lobe longer than lower), similar in form to that of sharks.
Size
Several species commonly reach 2–3.5 m (7–12 ft); some individuals have been recorded much larger.
Common lookalikes
Paddlefish (Polyodontidae)
Paddlefish are the only other living family in the order Acipenseriformes and may be encountered in some overlapping regions.
Range and Movement
How sturgeons move through the world
The broad range, seasonal movement, or migratory behavior that shapes where divers encounter this species.
Many sturgeon are anadromous bottom‑feeders that migrate upstream to spawn and spend much of their lives feeding in river deltas and estuaries; some species are exclusively freshwater, while others primarily inhabit marine coastal areas and may venture into the open ocean.
Diet
What sturgeons tend to eat
Useful feeding context that often explains habitat, movement, and encounter style.
Primarily bottom‑feeding; they feed along riverbeds, deltas and estuarine bottoms.
Conservation
What is happening with Sturgeons
Status, pressure, and protection context grounded in cited sources rather than filler.
Widespread overexploitation for roe, combined with other conservation threats, has resulted in severe declines and critical endangerment for most sturgeon species.
Main threats
Overexploitation for roe (caviar)
Several species are harvested for their roe, and this exploitation has been a major driver of population declines.
Other conservation threats
The family has faced additional unspecified conservation threats that, together with overexploitation, have pushed many species toward critical endangerment.
Responsible Encounters
How to dive with sturgeons
Conservation-minded guidance for divers who want the encounter without adding pressure.
Give sturgeon space, avoid blocking the animal's path, and follow local site and operator rules for wildlife interactions with freshwater fishes.
Field Notes
Interesting things worth knowing
Useful species context that makes the encounter more meaningful once you are underwater.
Field notes
Ancient lineage
Sturgeon fossils date to the Late Cretaceous, with acipenseriform relatives known from the Early Jurassic.
Diverse family
The common name covers 27 species in five genera within the family Acipenseridae.
Record size
The largest recorded sturgeon was a beluga captured in 1827, measured 7.2 m and weighed 1,571 kg.
FAQ
Frequently asked questions
Clear planning and conservation answers written for search visibility and AI retrieval.
Research Sources
Sturgeon information sources
Primary and credible references behind the field-guide and conservation claims on this page.
Sources 2Last Updated
Related Species
More in Freshwater Fishes
Related species guides in the same encounter family.
