We provide notes on the design and construction of an Electric Fish Finder - a portable differential amplifier for detecting the electrostatic fields of gymnotiform knifefishes. The device can be adapted to locate electric fishes in any kind of aquatic environment. It is rugged, water resistant, and powered by alkaline batteries. This contribution is part of a series of technical papers designed to encourage students of neotropical ichthyology to explore the ecology, systematics, and electric signaling of gymnotiform fishes.
Electric Organ Discharge; Gymnotiformes; Knifefishes; Method