Classification Of Fish

 

  

Fishes are poikilothermic animal(I.e they are cold blooded animals, they can not control their body 
temprature)

 

Classification Of Fish | Types and Their characteristics 

Elementry Classification of fish is usually on basis of habitat.  There are two main types of habitant in which fishes can be found, and these include;

• Fresh Water Fishes
• Salt Water Fishes

Fresh Water Fishes

These are water that has no salt taste. Examples of such water includes;

Streams, springs, rivers, ponds, swamps and lake. Fishes living in this type of water are called fresh water fishes. Examples of these types of fishes are; trout, pike, tilapia, perch, carp, mud fish and cat fish.

Salt Water Fishes

A salt water is any water that has salt taste, such as oceans and lagoons.

Tuna, salmon, mackerel, Eels, sharks, skates, rays etc are the examples of fishes that can be found in this type of water.

Fishes can also be classified on the basis of the structure of their bodies.

There are fishes whose body frame are made up of bones; these type of fishes are classified as Bony Fishes.

Those whose skeleton are made up entirely of cartilage rather than bone, are referred to as cartilaginous fishes

There are those that are jawless, they are referred to as Agnatha fishes

Bony Fishes 

These are type of fishes that posses a bony skeleton or hard bone. 

There 30,000 species of this fish around the world, most of which belonged to to finned group of fish.

They are further classify into ray finned fishes and lobe finned fishes

The ray finned fishes posses a thin, flexible  skeleton, why The lobe finned fishes posses muscular fins which are supported by bones.

Fishes classified under this category are; tilipia, mud fish, trout, bass, salmon, perch, cat fish, 

herring, cod fish, guppy etc.

Characteristics of bony Fishes

• They have paired fins
• They have jaws
• Their Gill arches support their gills and are protected by the operculum
• They possess more or less skeleton

Cartilaginous Fishes

These type of fish posses soft bone, or bones composed of cartilage.

There are about 600 species of this type of fish

Majority of this of type of fishes are found in the sea, sea been a salt water. these type of fishes  includes; sharks, salmon, dolphin, dog fish, skates, ray etc. 

Jawless Fish

As there name implies, they are fishes which lacked jaw.

Unlike bony fishes, they lacked paired fins, they possess circular tooth and internal skeleton organ.  This type of fishes are of two major groups; Hag fish and lampreys

Characteristics of Jawless Fish

• They have two or more niches
• They lack jaw
• They do not have stomach in their digestive system.