The American Paddlefish (Polyodon spathula) is named for it's protruding, paddle-like snout, which is covered in microscopic sensory organs that aid in the detection of prey. Paddlefish are long-lived species, commonly reaching ages of 20-30 years, and can reach lengths of up to 5ft and weight as much as 60lbs. However, this species is planktivorous, feeding on large quantities of tiny crustaceans (zooplankton) and other small invertebrates which are filtered from the water column by fine gill segments (pictured below). While paddlefish can be found in 22 US states throughout the Mississippi River basin, their numbers have declined in recent decades due in part to pollution, habitat degradation and overfishing. Alteration of river channels can also result in changes in flow, which may disrupt spawning habits of this species. .