Catfish

Catfish are very diverse group of bony fish. Catfish is divers group of fish that contains a wide variety of different species. Catfish are of considerable commercial importance; many of the larger species are farmed or fished for food, and some are exploited for sport fishing, including a kind known as noodling. Many of the smaller species, particularly the genus Corydoras, are important in the aquarium hobby. There are currently 37 known Catfish families. Catfish have one of the greatest ranges in size within a single order of bony fish. Many catfish have a maximum length of fewer than 12 cm.

Extant catfish species live in inland or coastal waters of every continent except Antarctica. They are found primarily in freshwater environments of all kinds, though most inhabit shallow, running water habitats. Most catfish are benthic in nature, meaning they normally associate with the bottom of the water column. However, varieties of other lifestyles are also represented among the catfishes. A wide range of feeding behaviors and diets are represented by the catfishes. The fertilization of eggs in catfish can be internal, external, or even include sperm passage through female digestive tracts, the so called sperm drinking type of fertilization.

Catfish have a variety of body shapes, but mostly have a cylindrical body with a flattened ventrum to allow for benthic feeding. The Catfish can be recognized on its well-known and prominent barbells. The barbells are elongated tactile organs located close to the mouth; quite similar to the whiskers on a cat. Just like the cat's whiskers, the barbells are used to screen the environment and heighten the animal's awareness of its surroundings. The barbells are equipped with taste buds and they use the barbells when catching fish in dark and cloudy waters where the visibility is low. Although, these barbells may be absent in some species. However, they are not the only species with barbells; barbells are also found on several carps, the goatfish and a few shark species. Another known characteristic in catfish is its lack of scales. They also have the hollow leading ray on the dorsal and pectoral fins. These are very strong and they use it to excrete a potent protein when they are frightened or annoyed. All catfish, except members of Malapteruridae (electric catfish), possess a strong, hollow, bonified leading spine-like ray on their dorsal and pectoral fins. These spines may be locked into place so that they stick outwards, which can inflict severe wounds, as their defense.

These species have been widely caught and farmed for food for hundreds of years in Africa, Asia, Europe, and North America. Judgments as to the quality and flavor vary, with some food critics considering catfish as being excellent food, others dismiss them as watery and lacking in flavor.