Shovelnose Sturgeon - Distribution, Habitat, and Reproduction

Distribution, Habitat, and Reproduction

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 to the hickorynut mussel.

A typical sturgeon's life history includes a migration from feeding grounds to breeding grounds in large rivers. During spawning, behavior changes and swimming near the surface occurs. Females do not spawn every year and spawning chronology is not readily evident. Spawning takes place over gravel in fairly swift water. Eggs hatch after 3 to 5 days, and the larvae—about 1 cm long—drift downstream to suitable rearing areas in the river (Barton 2007). Carlson et al. (1985) found that growth of the shovelnose sturgeon is relatively slow, at 21.3 inches (54.1 cm) in five years.