Electric catfish from Nigeria grow to 20 inches and can produce a shock of 200 volts to disable prey. The charge from a two inch electric catfish feels like touching an exposed Christmas tree light. Most of the guys at AquariumFishSale.com can attest to this. Electric catfish are catfish and will eat live, frozen, and sinking pellets. Electric catfish are classified as noctunal and during the day these fish usually just sleep around. At night these guys are pretty active.