Vertebrates

Vertebrates consist of animal species inside the Subphylum Vertebrata which means chordates having backbone. Animalia is the kingdom of vertebrates with subphylum Deuterostomia and phylum Chordata. Olfactores is its clade i.e. group of monophyletic with Agnatha and Gnathostomata as its infraphylums. The synonym or other name of vertebrates is Ossea Batsch. The living vertebrate animal size ranges from the species of frog  Paedophryne amauensis [7.7 millimeter or 0.30 inches] to blue whale [upto 30 meter or 108 feet]. The vertebrates include;

• Jawless fish (Lampreys and Hagfish)
• Jawed vertebrates [cartilaginous fish- ratfish, shark; bony vertebrates- ray fins, lobe fins (tetrapods and lungfish)].

The name vertebrates is given to these species because they have vertebrae or backbone. Examples of vertebrates are as follows;

• Birds (Aves)
• Amphibians (Amphibia).
• Reptiles (Reptilia)
• Fishes (Osteichthyes)
• Mammals (Mammalia).

Classification of Vertebrates

Subphylum Vertebrates are classified into 7 classes and these are as follows;

• Class Aves
• Class Amphibia
• Class Reptilia
• Class Agnatha
• Class Osteichthyes
• Class Mammalia
• Class Chondrichthyes

1) Class Aves

Birds are mostly referred to as Avian Dinosaurs. The toothless beaks, high and good metabolic rate as well as feathers are some of the characteristics of birds. Class Aves members lay eggs with hard shells and are animals with warm blood.

2) Class Amphibia

Amphibians consist of ectothermic (cold blooded animals) tetrapods like salamanders and frog toads. Their eggs do not have shells so for breeding they require a watery body. They undergo reincarnation or metamorphosis in which young ones change from fully grown larval (aquatic) form to adult form.

3) Class Reptilia

It includes turtles, snakes, tuataras and crocodiles. These are cold blooded animals (ectothermic) and do not contain visible or revealed limbs.

4) Class Agnatha

These are primitive jawless fishes with the mouth circular in shape and small sharpened teeths for the purpose of feeding and holding the kind of fish. Most of them are scavengers and parasites.

5) Class Osteichthyes

It is the class of bony fish and the skeleton of Osteichthyes has bones and does not have cartilages like sharks and is the largest vertebrate class.

6) Class Mammalia

The mammals or mammalia have capability of regulating and maintaining the temperature of their body irrespective of the temperature of surroundings, hence it is regarded as endothermic animals which consists of platypuses and humans.

7) Class Chondrichthyes

The skeleton of animal species of this class have cartilages like rays, sawfish, sharks and skates. Sharks like Greenland sharks live for many centuries and are found to be 273 years old.

Characteristics of Vertebrates

The characteristics of Vertebrates are as follows;

• Notochord (stiff rod) is present in humans as embryos which therefore developed into vertebral columns.
• Above this vertebral column several nerves come and below this alimentary canal exists which end in anus.
• The animal’s anterior portion consists of the mouth.
• Through the animal’s length a stiff rod runs (notochord) and above it the spinal cord is present and below it gastrointestinal tract is present.
• The most important characteristics of vertebrates is their backbone or vertebral column.
• All the vertebrates which are basal have gills which help them in breathing.
• The hollow nerve cord has the central nervous system of vertebrates which run along the animal’s length.

Conclusion

The vertebrates are the animal species having vertebral column or backbone or vertebrae. These are classified into 7 classes which includes Aves, Amphibia, Reptilia, Agnatha, Osteichthyes, Mammalia and Chondrichthyes. Examples of vertebrates are Birds, Amphibians, Reptiles, fish and mammals. The vertebrate animals include reptiles, humans, birds, fish, mammals and amphibians and are also referred to as Craniata. Snail is an invertebrate species of animal as it does not have the vertebrae.