The pallid sturgeon was listed by the U.S. Fish & Wildlife as endangered in 1990. The pallid looks more at home in a natural history museum than on the end of a fisherman's line, although whether that's because of its age or appearance is a tossup. It has a flat, upturned shovel of a nose and long, fleshy whiskers called barbels. These are used to sense the river bottom and to identify prey, allowing their vacuum cleaner-like mouth to quickly capture it. Prey consists of aquatic insects and small bottom dwelling fish.
The belly of the pallid is completely without bony plates throughout its life and the barbels are positioned differently from those of the shovelnose sturgeon. In the shovelnose, all four barbels are in line and evenly spaced in front of the mouth. In the pallid, the outer barbels are placed slightly farther back.
Over millennia, these fish have adapted to spawn in synchronization with the spring rise of the river, an event that ceased with the construction of the dams; thus, there has been virtually no natural reproduction for over fifty years.