Any of about 2,500 species of scale-less, mostly freshwater, fishes (order Siluriformes) related to carp and minnows and named for their whiskerlike barbels (fleshy feelers). All species have at least one pair of barbels on the upper jaw, and some have a pair on the snout and additional pairs on the chin. Many species possess spines that may be associated with venom glands. Found almost worldwide, they are generally bottom-dwelling scavengers that feed on almost any kind of plant or animal matter. Species vary from 1.5 in. to 15 ft (4 cm–4.5 m) long and may weigh up to 660 lbs (300 kg). Many small species are popular aquarium fishes; many large species are used for food.