Knifefish are a group of freshwater fish belonging to the order Gymnotiformes. They are primarily found in the rivers and lakes of South America, particularly in the Amazon Basin. Known for their elongated bodies and unique swimming style, knifefish use their long, flattened tails to propel themselves through the water. These fish are also notable for their ability to generate electric fields, which they use for navigation, communication, and hunting. Some species can produce strong electric shocks, making them fascinating subjects for scientific research and popular in the aquarium trade.