Catfish is the ray-finned fish. Catfish is the most popular and most diverse group of fish. They ranked second among all vertebrates in terms of diversity. Catfish are named due to their barbels which resemble a cat's whiskers.

Range:

Catfish are present over all continents except Antarctica. It is mostly present in freshwater environments, and some are also present in marine ecosystems.

Catfish are diversely present across tropical South America, Africa, Asia. In addition, one of the species is present in North America. 

Habitat:

Catfish in freshwater environments are present from fast-moving mountain streams to slow torpid waters, while they are present near the shore in marine environments.

They mostly inhabit the clear to muddy water. They are bottom feeders and have reduced gas bladder, so they sink rather than float. They are mostly active during the night instead of the day.

Physical Characteristics:

• Catfish have various body shapes, from cylindrical with a flattened ventrum and a heavy, bony head.
  

• They are dull-colored; however, some species of North America have bright color patterns.

• Catfish do not have scales but have spines in the front of their fins, and in some species, the body is covered with a mucus layer.

• Many catfish reach a length up to 12 cm.

• The weight of different species may vary according to different locations and may weigh from 88kg to 300 kg.

• Catfish have unexceptional taste and smell capabilities. Catfish also have good vision in clear water and can also detect vibrations.

Species:

Almost about 3000 species of catfish are known. The major catfish species are

• Blue Catfish

• Channel Catfish

• Flathead Catfish

Blue Catfish:

Scientific Name:

Ictalurus furcatusis the scientific name of blue catfish. 

Other Names:

Other names are high fin blue, hump-black blue, Mississippi white catfish.

Appearance:

Color:

Slate blue to white and dark blue or black and blue catfish does not have spots. 

Fin and Tail:

The body is large and smooth and lacks scales. The tail is fork-shaped and anal fins are straight with 30-36 rays.

Barbels:

Blue catfish have four pairs of whisker-like barbies that are used for food searching.

 Distribution:

Blue catfish are native to,

• Mississippi river basins

• Missouri

• Ohio

• Texas

• Northern Guatemala

• Mexico

Channel Catfish:

Scientific Name:

Ictalurus Punctatusis the scientific name of channel catfish.

Other Names:

Graceful catfish, lake catfish, lady cat, white cat, spotted cat are the common catfish names.

Appearance:

Color:

Channel fish is olive to brown with dark spots. 

Fin and Tail:

Curved anal fin with 29 rays and tail is forked shaped. 

Barbels:

They have four pairs of barbels.  

Distribution:

Channel catfish is most common in the United States due to two main reasons. Firstly, they are easily available in most rivers and lakes of the US and secondly, they make excellent table fare.

Its range extends from southern Canada into northern Mexico.

Flathead Catfish:

Scientific Name:

Pylodictis Olivarisis the scientific name of Flathead catfish.

Other Names:

The common names of Flathead catfish are yellow cat, mud cat, pied cat, opelousa catfish.

Appearance:

Color:

Most Flathead catfishes are pale yellow, brown, and mottled black. 

 Fin and Tail:

The tail is not forked. The anal fin is short and round with 30 rays and has a slight notch in them.

Barbels:

Cat-like whiskers around the mouth. Long and sharp spines on the back. 

Distribution:

It is the largest species in North America. It ranges from the Great Lakes region to northern Mexico.