They are easy to identify as a group. Some species grow to a length of over 20 ft. (6 m) and well over 2,000 lb. (907 kg) and may live to be over 100 year old. The body is long and heavy and is covered with 5 rows of large, heavy scutes. One row runs along the middle of each side, one along the back and two along the belly. The scutes become smoother as the sturgeon grows older and in some species, they may gradually disappear by absorption. On each side of the head there is a huge bony plate that serves as the gill cover. The rest of the head is covered with smaller bony plates. The mouth is protrusible, like the sucker�s, and is preceded by four barbels resembling a mustache. The eyes are small by comparisons to the overall size of the body. The single dorsal fin is located far back on the body near the tail and directly above the anal fin. The tail is heterocercal (the upper lobe is longer than the lower lobe).

The sturgeon roe is the only true caviar. The largest and most highly prized eggs come from the beluga (Huso huso) in Russia. This species has been recorded up to a weight of 3,359 lb. (1,524 kg) and a female weighing 2,707 lb. (1,228 kg) caught in 1924 yielded 542 lb. (246 kg) of roe. A smaller, highly desirable, sturgeon from Russia is the osietr (A. sturio) which produces a golden-brown caviar preferred by some European gourmets. The sterlet (A. ruthenus), which is almost extinct, produce the legendary �gold caviar of the Czars.�

The most highly regarded North American species is the white sturgeon, both for its flesh and its roe. It may produce up to 200 lb. (90.72 kg) of eggs, which are readily marketed as caviar. Two other North American species, the lake sturgeon and the Atlantic sturgeon, are also well regarded. The latter is often referred to as �Albany beef� and the roe of both species is sold as caviar. The green sturgeon although edible is said to have dark flesh with an unpleasant odor and a strong. disagreeable taste.