Shovelnose sturgeon

Species of fish

The shovelnose sturgeon (Scaphirhynchus platorynchus) with which shovelnose sturgeon are sympatric.

The sturgeons of the family Acipenseridae have bony scutes along the sides and back and four barbels on the underside of the rostrum. A total of 25 extant species of sturgeon are recognized, including 17 within the genus Acipenser. Sturgeon are distributed around the northern part of the Northern Hemisphere (holarctic distribution) and have marine, freshwater, and anadromous members. Sturgeons, including the shovelnose, are highly regarded for their flesh and their roe, from which premium grades of caviar are made (Barton 2007). They can reach in length and up to in weight but and is more common. The scientific name Scaphirhynchus, Greek, means "spade snout", and platorynchus, Greek, means "broad snout". The shovelnose sturgeon is characterized by a long slender filament on the upper lobe of the caudal fin. They have a flattened rostrum (modified snout) that is also shovel shaped. There are four fringed barbels on the ventral side of the rostrum that can be found in a straight line, which is equidistant from the mouth opening to the tip of the snout, unlike pallid sturgeon. The belly of the shovelnose sturgeon is covered with scale like plates, which is another distinguishing factor from pallid sturgeon who have primarily scaleless bellies. Coloration of the shovelnose sturgeon ranges from a light brown to buff with a white belly (Pflieger 1997).

The shovelnose sturgeon, as its distribution represents, is impacted very little by turbidity. The Missouri River and the Mississippi River systems tend to carry high sediment loads. Here the sturgeon inhabits the open channel or main channel areas of the large rivers. It lives on the bottom, often in areas with swift current and sand or gravel bottom. As with many riverine fish species, the shovelnose sturgeon does not have a restricted home range and may travel long distances (Pflieger 1997). The shovelnose sturgeon feeds on the bottom, using its highly protrusible mouth to suck up its food. The diet is mainly aquatic insect larvae, consisting principally of mayflies, true flies (Diptera), and caddisflies. The sturgeon also feed on crustaceans, worms, and small fish (Carlson et al. 1985;Held 1969). As a result, to bottom feeding it is a host to the glochidia (larvae) of several species of freshwater mollusc, including Quadrula pustulosa (pimpleback), Obovaria olivaria (hickorynut) and Lampsilis teres (yellow sandshell). It is the only known host of the hickorynut mussel.