The Freshwater Stingray, Potamotrygon sp., is another psammophilic fish. Often times they are found in shallow waters with sand or silt bottoms. They can bury themselves with only their eyes above the substrate. They wait for small invertebrates to come to close and pounce on them. Freshwater stingrays have a barb on their tails that they can use in defense. Dangerous bacteria often times live on the barb and can cause serious infections in humans that accidentally step on a ray and are pierced by the barb. This species of stingray is one of the species often exported for the aquarium trade. This specimen was photographed in the Peruvian Amazon 2010.