New York Natural Heritage Program
Atlantic Sturgeon
Acipenser oxyrinchus Mitchill, 1815
Ray-finned Fishes

Identifying Characteristics [-]
The Atlantic sturgeon is a fairly large and primitive-looking fish, with a shark-like tail (heterocercal caudal fin) and rows of boney plates on the head and along the body. There are 6 to 9 bony plates, mostly in pairs, behind the dorsal fin. The snout is long and narrow, upturned in young fish, and sharply V-shaped, with the mouth and four large fleshy barbells located on the underside. The coloration varies from olive-green to blue-black on the upper sides, gradually shading to white on the underside. The boney plates along the back have white tips. Atlantic sturgeon that weigh more than 200 pounds have been taken in the Hudson River, and the species can attain lengths of up to 14 feet and weigh up to or greater than 800 pounds. The eggs, also known as caviar, are sticky and turn black as they develop (Stegemann 1994, Smith 1985).

Characters Most Useful for Identification [-]
The long, pointy snout, and great length of adult fish distinguishes the Atlantic sturgeon from the shortnose sturgeon (Acipenser brevirostrum), which are the only two species of sturgeon in the Hudson River. Atlantic sturgeon have several bony plates along the base of the anal fin and these are not present in shortnose sturgeon. The width of the mouth on specimens as small as three inches can also be used to differentiate between the two species (Smith 1985).

Best Life Stage for Proper Identification [-]
Both adults and juveniles can be identified from shortnose sturgeon.

Behavior [-]
Atlantic sturgeons migrate from saltwater to freshwater to reproduce. They typically reach sexual maturity around 9 years of age. During spawning, the sticky eggs are broadcast, attaching themselves to vegetation or the bottom of the river and are left unattended. A female can carry over one million eggs. They gradually turn black and hatch in 8-10 days. The young can remain in freshwater for up to seven years before heading out to the sea. Sturgeons may be seen basking near the surface of the water (Stegemann 1994, Smith 1985).

Diet [-]
The Atlantic sturgeon is a bottom feeder, consuming worms, amphipods, isopods, and small fish, especially sand lance. In freshwater, they eat insects, amphipods, and oligochaetes (Smith 1985).
Atlantic Sturgeon Images
click to enlarge
The Best Time to See
Adult males move up the Hudson River to spawn starting in April, with females arriving in May. They move back to the sea between August and November, with the females leaving after spawning.
Active Reproducing
The time of year you would expect to find Atlantic Sturgeon active (blue shading) and reproducing (orange shading) in New York.
Similar Species
  • Lake Sturgeon (Acipenser fulvescens)
    The lake sturgeon has the anal fin origin behind the dorsal fin origin, has a longer caudal peduncle, scutes on back and sides the same color as the skin, 25-30 anal rays, usually 32-35 gill rakers, and 29-42 scutes along each side (22-33 in shortnose).
  • Shortnose Sturgeon (Acipenser brevirostrum)
    The shortnose sturgeon is the smallest of the three sturgeons, rarely exceeding 3 feet, and has a shorter snout. The dorsal and lateral bony plates are light in color.