Sturgeon is the common name for the 27 species of fish belonging to the family Acipenseridae.
They are all found in the northern hemisphere. They range from subtropical to subarctic waters in North America and Eurasia.
Sturgeons are mostly live in large, freshwater lakes and rivers but some species also travel to the ocean and return to rivers and lakes to breed.
Sturgeons are long-lived, late maturing fishes. Their average lifespan is 50 to 60 years, and their first spawn does not occur until they are around 15 to 20 years old.
Sturgeons ranging from 2 to 3.5 meters (7–12 feet) in length are common, and some species grow up to 5.5 meters (18 feet).
The largest sturgeon on record was a Beluga female captured in the Volga estuary in 1827, weighing 1,571 kg (3,463 lb) and 7.2 meters (24 ft) long.
Sturgeons have bony plates (scutes) covering the head and five longitudinal rows of similar plates along the body. The tail fin is heterocercal, the upper lobe being longer than the lower. Their mouths are positioned ventrally and have 4 barbels.
Most sturgeons are anadromous bottom-feeders which migrate upstream to spawn but spend most of their lives feeding in river deltas and estuaries.
Their diet composed of shells, crustaceans and small fish.
They migrate upstream to spawn but spend most of their lives feeding in river deltas and estuaries.
Many sturgeon leap completely out of the water, usually making a loud splash which can be heard half a mile away on the surface and probably further under water. It is not known why they do this, but suggested functions include group communication to maintain group cohesion, catching airborne prey, courtship display, or to help shed eggs during spawning.
Sturgeons are valued for their flesh, eggs, and swim bladder. Their flesh is sold fresh, pickled, or smoked. Caviar consists of the eggs, which are stripped from ripe females who are subsequently released.
Almost all caviar is harvested from dead fish. Fishermen on the Caspian wait until the mature female sturgeon (which are at least 10 years old) are ready to migrate upstream and lay their eggs. Once caught, the sturgeon will be transferred to a large boat, where workers slit her open and remove her eggs. The caviar is cleaned to prevent spoilage and then packed up; the rest of the fish is sold for flesh.
The word “caviar” is ultimately derived from Persian khavyar, from khaya meaning “egg.” The word first appeared in English print in 1591.
You can hear caviar. The friction can be heard when you rub fish eggs together. Good caviar’s sound is clearly distinguishable and sounds like a cat’s purr.
Despite surviving on Earth for millions of years, sturgeon are now vulnerable to overfishing and interference in their natural habitat.
Their evolution dates back to the Triassic some 245 to 208 million years ago.
According to the IUCN, over 85% of sturgeon species are classified as at risk of extinction, making them more critically endangered than any other group of species.
In art, a sturgeon is the symbol on the coat of arms for Saint Amalberga of Temse.