Green sturgeon
| Green sturgeon | ||||||||||||
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Green sturgeon ( Acipenser medirostris ) |
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| Scientific name | ||||||||||||
| Acipenser medirostris | ||||||||||||
| Ayres , 1854 |
The green sturgeon ( Acipenser medirostris ) is a species of fish from the family of the sturgeon (Acipenseridae) and occurs on the Pacific coast of North America from the Aleutian Islands to the heights of Ensenada in the Mexican state of Baja California . The sturgeons similar to this species on the Northeast Asian side of the Pacific are now considered to be a separate species ( Sakhalin sturgeon ( Acipenser mikadoi )).
features
The green sturgeon reaches an average length of 1.30 meters, a maximum of 2.50 meters long, with a maximum weight of 159 kg. Its color is mostly olive to dark green, the underside whitish-green, the fins gray to pale green. An olive-green longitudinal stripe runs between the lateral and ventrolateral bone plates, and another along the midline of the abdomen. The lateral row of bone plates consists of 23 to 30 bone plates. The species is characterized by a single row of one to four bone plates along the midline between the anus and anal fin. The dorsal fin lies in the rear third of the body, the anal fin lies under the rear dorsal fin section. The pectoral fins are attached to the abdomen behind the gill openings and are large and rounded. The pelvic fins are located near the anus.
Fin formula : dorsal 33–35, anal 22–28.
The four barbels are usually closer to the mouth than the tip of the rostrum . The rostrum is shovel-shaped in young fish.
Way of life
The green sturgeon occurs near the coast in the sea, in the salt and brackish water of estuaries and in the fresh water of the river lower reaches. It stays more in the sea than the white sturgeon ( Acipenser transmontanus ) and undertakes long migrations there. Large concentrations of the fish are found at times in the mouths of the Columbia and Fraser Rivers in Canada, in Willapa Bay , Grays Harbor in Washington state , and in the mouths of the Eel , Sacramento and San Joaquin Rivers in California . He spawns in fresh water. Only three rivers are known to be spawning areas in the United States today, the Rogue River in Oregon , the Klamath River and the Sacramento River in California.
Danger
Green sturgeon meat is edible, but it has an unpleasant taste and smell. Its habitat has been restricted by the construction of dams. The IUCN estimated in 2006 that the total population of the species is between 34,000 and 166,000 adult and almost fully grown fish and is therefore at low risk.
literature
- Eschmeyer, Herald, Hamann: Pacific Coast Fishes , Peterson Field Guides, ISBN 0-395-33188-9
Web links
- Green sturgeon on Fishbase.org (English)
- Acipenser medirostris in the endangered Red List species the IUCN 2006. Posted by: St. Pierre, R. & Pourkazemi, M. (Sturgeon Red List Authority), 2009. Accessed November 15 of 2010.