Acipenser medirostris NatureServe Explorer Species Reports — NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and Canada. NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.

ITIS Reports –Acipenser medirostris  ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world.

FWS Digital Media Library — The U.S. Fish and Wildlife Service’s National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video.Sturgeons are among the largest and most ancient of ray finned fishes. They are placed, along with paddlefishes and numerous fossil groups, in the infraclass Chondrostei, which also contains the ancestors of all other bony fishes. The sturgeons themselves are not ancestral to modern bony fishes but are a highly specialized and successful offshoot of ancestral chondrosteans, retaining such ancestral features as a heterocercal tail, fin structure, jaw structure, and spiracle. They have replaced a bony skeleton with one of cartilage, and possess a few large bony plates instead of scales. Sturgeons are highly adapted for preying on bottom animals, which they detect with a row of sensitive barbels on the underside of their snouts. They protrude their very long and flexible “lips” to suck up food. Sturgeons are confined to temperate waters of the Northern Hemisphere. Of 25 extant species, only two live in California, the green sturgeon and the white sturgeon (A. transmontanus). (Moyle 2002)