Acipenseridae
There are 23 species of sturgeons , all found in the northern hemisphere. They are mostly found in large, freshwater lakes and rivers but some species also travel to the ocean and return to rivers and lakes to breed. Sturgeons can grow to be very large, up to 4.2 meters. This is a primitive fish family, sturgeons have rows of large, bony scutes on their bodies instead of fine, rows of scales. Their mouths are positioned on the bottoms of their heads and have 4 “barbels” near them. Barbels are sensory organs, helping sturgeons to feel their way around and find food. All sturgeon species have been extensively used by humans for their meat and their roe (fish eggs), which is what “caviar” is made from. As a result, all sturgeon species are either threatened or endangered.