Catfish are a diverse group of ray-finned fish.
There are nearly 2,900 species of catfish in existence today.
Catfish species live inland or in coastal waters of every continent except Antarctica. They are most diverse in tropical South America, Asia and Africa with one family native to North America and one family in Europe.
Catfish can live up to 60 years depending on location and species.
Catfish have one of the greatest ranges in size within a single order of bony fish. Some of the smallest species of Aspredinidae and Trichomycteridae reach sexual maturity at only 1 centimeter (0.39 in). The average size of the species is about 1.2–1.6 m (3.9–5.2 ft), and fish more than 2 meters (6.6 ft) are rare. However, they are known to exceed 2.5 meters (8.2 ft) in length and 100 kilograms (220 lb) in weight.
The name “catfish” refers to the long barbels, or feelers, which are present about the mouth of the fish and resemble cat whiskers. All catfishes have at least one pair of barbels, on the upper jaw; they may also have a pair on the snout and additional pairs on the chin. Many catfishes possess spines in front of the dorsal and pectoral fins. These spines may be associated with venom glands and can cause painful injuries to the unsuspecting. All catfishes are either naked or armoured with bony plates; none has scales.
Most catfish are bottom feeders. In general, they are negatively buoyant, which means that they will usually sink rather than float due to a reduced gas bladder and a heavy, bony head.
Many catfish are nocturnal, but others are crepuscular or diurnal.
The diet of catfish often changes as they age. Young catfish primarily feed on aquatic insects such as dragonfly larvae, water beetles and fly larvae. By the time they’re adults, catfish consume small fish, seeds, aquatic plants, algae, crawfish and snails.
Catfish are easy to farm in warm climates, leading to inexpensive and safe food at local grocers. About 60% of U.S. farm-raised catfish are grown within a 100-km (65-mile) radius of Belzoni, Mississippi.
Catfish can produce different types of sounds and also have well-developed auditory reception used to discriminate between sounds with different pitches and velocities. They are also able to determine the distance of the sound’s origin and from what direction it originated. Catfish are able to produce a variety of sounds for communication that can be classified into two groups: drumming sounds and stridulation sounds.
The flathead catfish can lay up to 100,000 eggs during one spawning cycle. After the eggs are laid, they hatch within five to ten days. Once the eggs hatch, the fry (young fish) have a yolk-like sac that nourishes them for two to five days until it dissolves and they are fully developed.
In the Southern United States, catfish species may be known by a variety of slang names, such as “mud cat”, “polliwogs”, or “chuckleheads”.
Catfish is eaten in a variety of ways. In Europe it is often cooked in similar ways to carp, but in the United States it is popularly crumbed with cornmeal and fried.
Judgments as to the quality and flavor vary, with some food critics considering catfish excellent to eat, while others dismiss them as watery and lacking in flavor. Catfish is high in vitamin D. Farm-raised catfish contains low levels of omega-3 fatty acids and a much higher proportion of omega-6 fatty acids.