Catfish are a diverse group of fish known for their distinctive whisker-like barbels around their mouths, which resemble a cat's whiskers. Found in freshwater and saltwater environments around the world, they vary greatly in size, with some species growing as large as several hundred pounds. Catfish are bottom-dwellers, using their barbels to detect food, and many species are omnivorous, feeding on plants, small fish, and detritus.