Cat fish

Introduction:
Catfishes (orderSiluriformes) are a diverse group of ray-finned catfish. Named for their prominent barbels, which resemble a cat whiskers, catfish range in size and behavior from the heaviest and longest, the mekong giant catfish from Southeast Asia and the second longest, the wels catfishh of Eurasia, to detritvores (species that eat dead material on the bottom), and even to a tiny parasitic species commonly called the candiru,Vandellia cirrhosa. There are armour-plated types and also naked types, neither having scales. Despite their name, not all catfish have prominent barbels; members of the Siluriformes order are defined by features of the skull and swimbladders. Catfish are of considerable commercial importance; many of the larger species are farmed or fished for food. Many of the smaller species, particularly the genus corydoras, are important in the aquariumhobby.

Habitat:

Extant catfish species live inland or in coastal waters of every continent except antarctica. Catfish have inhabited all continents at one time or another Catfish are most diverse in tropical South America, North America, Africa, and Asia More than half of all catfish species live in the Americas. They are the only ostariophysians  that have entered fresh water habitats in madagascar, Australia, and new guinea

They are found in freshwater environments, though most inhabit shallow, running waterRepresentatives of at least eight families are hypogen (live underground) with three families that are also troglobitic (inhabiting caves).One such species is phreatibuos cistermarum known to live underground in phreatic habitats. Numerous species from the families ariidae and plotosidae and a few species from among the asprinadie and bagridae are found in salt water.

In the United States, catfish species may be known by a variety of slang names, such as "mud cat", "polliwogs", or "chuckleheads"

Sound production and intrepption:

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 in what direction it originated.This is a very important fish communication mechanism, especially during agonistic and distress behavior. Catfish are able to produce a variety of sounds for communication that can be classified into two groups: drumming sounds and stridulation sounds. The variability in catfish sound signals differs due to a few factors: the mechanism by which the sound is produced, the function of the resulting sound, and physiological differences such as size, sex, and age.In order to create a drumming sound, catfish utilize an indirect vibration mechanism using a swimbladder. In these fishes, sonic muscles insert on the ramus Mulleri, also known as the elastic spring. The sonic muscles pull the elastic spring forward and extend the swimbladder. When the muscles relax, the tension in the spring quickly returns the swimbladder to its original position, which produces the sound.Catfish also have a sound generating mechanism in their pectoral fins. Many species in the catfish family possess an enhanced first pectoral fin ray, called the spine, which can be moved by large abductor and adductor muscles. The base of the catfishes’ spine has a sequence of ridges, and the spine normally slides within a groove on the fish’s pelvic girdle during routine movement; but, pressing the ridges on the spine against the pelvic girdle groove creates a series of short pulses. The movement is analogous to a finger moving down the teeth of a comb, and consequently a series of sharp taps is produced.

Dangerous to human:

Many catfish species have “stings” (actually non-venomous in most cases) embedded behind their fins; thus precautions must be taken when handling them.While the vast majority of catfish are harmless to humans, a few species are known to present some risk. Perhaps the most notorious of these is the candiru, due to the way it is reputed to parasitize the urethra, though there is only one documented case of a candiru attack on a man.