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Green Sturgeon(Acipenser medirostris) |
The green sturgeon is a primitive, bottom dwelling fish. It is characterized by its large size and long round body. There are four barbels located in front of its large toothless mouth located on the bottom (ventral) side of the head. The sturgeon has no scales, instead it has "scutes" (or diamond plates) located along their bodies. Scutes are actually large modified scales, that serve as a type of protective armor. Green sturgeon have 9-11 scutes on their back (dorsal) located in front of a single dorsal fin, 1-2 scutes trailing the dorsal fin, 23-30 scutes along the side, and 7-10 scutes on the ventral side. The dorsal body color is a dark olive-green, with the ventral surface a lighter whitish green, with the scutes having a lighter coloration than the body. Green sturgeon can reach 7 feet in length and weigh up to 350 pounds.
Very little is know about the green sturgeon's life history. The green sturgeon is an anadromous fish that spends most of its life in salt water and returns to spawn in fresh water. It is a slow growing and late maturing fish that apparently spawns every 4 to 11 years during the spring and summer months. The green sturgeon spends limited time in fresh water; only while young and spawning. Adult fish and older juveniles are commonly found in estuaries and marine environments.
Green sturgeon are highly migratory in the ocean.
Fish tagged in the Sacramento/San Joaquin estuary have been found in the Columbia River and Grays Harbor, Washington one year later.
