Difference Between Vertebrates and Invertebrates

Animals are broadly classified into two categories based on the presence of backbone (vertebrates) and they belong to kingdom animalia. They have well developed internal skeleton, highly developed brain, have advanced nervous system, outer covering of protective cellular skin.

Vertebrates are classified in to 5 groups:

Fish

Amphibian

Reptiles

Birds

Mammals

What are Invertebrates:

Animals with lack of back bone (invertibrates) are invertebrates. They belong to the kingdom animalia and they are multicellular, no back bone, no cell walls, reproduce sexually, heterotrophic and are classified in to 30 plus phyla and they are small and slow moving and 98 percent of animals are invertebrates and they are 2 million species.

Organisms belonging to sub-phylum, vertibreta of phylum Chordata have a backbone and are classified as vertebrates. The organisms of all other phylum do not contain a vertebral column making them invertebrates.

Animal kingdom is divided in to 10 major phyla:

Protozoa

Porifera

Coelenterata

Platyhelminthes

Nemathelminthes

Annelida

Arthropoda

Mollusca

Echinodermata

Chordata 

Each of these with the exception of the sub phylum vertibreta are grouped under the category of invertebrates.

Difference Between Vertebrates and Invertebrates

Cockroach as an Example of invertebrate:

• Their body shows three distinct parts
• Head
• Thorax
• Abdomen
• And there is a thick hard cutaneous layer that covers the body as an exoskeleton but there is no endoskeleton. The cockroach have gangliated double ventral nerve cord. Its body cavity is known as the haemocoel and lacks haemoglobin and red blood cells.
• The Respiratory organs are its tracheae.
• Its Dorsal Heart has 13 chambers and blood flows in to body cavities meaning it is an open circulatory system.

Fish as An example of Vertebrate:

• Has a body of three distinct regions:
• Head
• Trunk
• Tail
• The endoskeleton is cartilaginous and bony
• There is a two chambered heart present on the mid ventral side of the body.
• The circulatory system is closed as it flow through blood vessels.
• The blood contains red blood cells with hemoglobin which is used in the transportation of respiratory gasses.
• Bracheal gills are primary respiratory organs.
• Paired and unpaired fins aid in locomotion

By above two examples of cockroach as an invertebrate and Fish as Vertebrate, the difference between vertebrate and invertebrate is clear and now its easy to understand the difference between vertebrates and invertebrates.

Vertebrate and invertebrate examples:

Vertebrates includes Fish, Amphibian, Reptiles, Birds, Mammals and Invertebrates include sponges, jellyfish, worms, molluscs, arthropods, and starfish.

Characteristics of vertebrates:

They have back bone and the series of structure which protect spinal cord or nerve cord, closed circulatory system, well developed organ system.