The lake sturgeon (Acipenser fulvescens), also known as the rock sturgeon, is a North American temperate freshwater fish, one of about 25 species of sturgeon. Like other sturgeons, this species is a bottom feeder with evolutionarily basal traits among fish, reflecting its early divergence from the shark lineage. These traits include a partly cartilaginous skeleton, an overall streamlined shape, and skin bearing rows of bony plates on the sides and back. The lake sturgeon uses its elongated, spade-like snout to stir up the substrate and sediments on the beds of rivers and lakes to feed. Four sensory organs (barbels) hang near its mouth to help the sturgeon locate bottom-dwelling prey. Lake sturgeons can grow to a large size for freshwater fish, topping 7.25 ft (2.2 m) long and 240 lb (108 kg). (Source: Wikipedia.org, CC BY-SA)