STURGEON (AF. sturjoun, OF., Fr. esturgeon, Sp. esturion, It. storione, from ML. sturgio, sturio, from OHG. sturjo, sturo, Ger. Stör, AS. styria, stiriga, sturgeon; perhaps connected with OHG. stōran, Ger. stören, AS. styrian, Eng. stir). A large fresh-water fish of the ganoid family Acipenseridæ. Sturgeons have an elongated, subcylindrical body, armed with five rows of bony plates or bucklers, each bearing a median keel. The head is covered by bony plates joined by sutures. The snout is produced; the mouth is inferior, opening on the under side of the head, protractile and without teeth. Just anterior to the mouth there are four barbels. The tail has the upper lobe much larger than the lower. There is a single dorsal fin, placed like the anal fin far back. They have a large air bladder, connected by a tube with the œsophagus.
About 25
species, in two genera, are recognized, all
inhabitants of the fresh waters and seas of the
northern regions. Most of the species are migratory
and ascend streams to spawn, but some live
permanently in fresh waters. They spawn in the
spring and summer, and are very prolific, a large
female producing from two to three million
eggs, constituting from a fifth to a third of its
entire weight. They feed on small animals and
plants, which they suck into their mouth.
The
common sturgeon (Acipenser sturio), of the coasts
and rivers of Europe and Northeastern America, has been known to weigh 500 pounds. The lake or rock sturgeon (Acipenser rubicundus), once very abundant in the Great Lakes and the Mississippi Valley, attains a weight of 200 pounds,
but the average is much less. Its sides are
reddish, often with irregular blackish spots. Very
peculiar in its prolonged paddle-shaped snout is
the ‘shovelnose’ or ‘white’ sturgeon
(Scaphirhynchus platyrhynchus), which is pale olive in
color and about five feet long. It is a denizen of
the Western and Southern States. Similar
species occur in Asia. The largest of American
sturgeons is that of the Pacific Coast (Acipenser
transmontanus) called ‘white’ in comparison
with the rare ‘green’ sturgeon (Acipenser
medirostris). The former weighs 300 to 600 pounds, and is used as food, but the latter, which is nearly as large, but olive green, is not eaten. A giant beside these is the great Russian ‘bielaga’ or ‘huso’ (Acipenser huso), which has been known to attain a length of 20 to 25 feet and a weight of 3000 pounds. It is this species, once extremely abundant in the Danube, Volga, and other large rivers emptying into the Black and Caspian seas, which has furnished mainly the salted roe called caviar (q.v.), though some comes from the diminutive sterlet (Acipenser ruthenus) of the same region. The air bladder is also utilized for making isinglass.
Fossil sturgeon remains indistinguishable from
the corresponding portions of the skeletons of
modern species have been found in rocks as old
as the Eocene. Earlier less specialized ancestral
forms are Chondrosteus of the Jurassic and
perhaps also the still older Palæoniscus of the
Permian and Cheirolepis of the Upper Devonian. See ; ; .
Consult authorities cited under and
; and see Plate of .