Difference between Invertebrates and Vertebrates

Main difference

The main difference between invertebrates and vertebrates is that invertebrates do not have the backbone with the spinal cord, but in the case of vertebrates, animals have a well-developed internal skeleton of cartilage and bone.

Invertebrates vs Vertebrates

Animals are divided into two main groups, one being invertebrates and the other being vertebrates. Invertebrates are those animals that do not have a backbone, but vertebrates are those animals that have a healthy backbone and an internal cartilage skeleton. Invertebrate animals are small in size because they do not have a well-developed organ system, so their size is still small, but vertebrates include those animals that share from small to large because they have a more advanced organization of body structure. Invertebrates cover around 98% of the animal kingdom while vertebrates cover only 2%.

Comparative chart

Invertebrates Vertebrates
Animals without backbones are called invertebrates. Animals with a strong backbone are known as vertebrates.
Body symmetry
They have radial or bilateral body symmetry. They have only bilateral body symmetry
Body structure
They have a simple body structure. They have a complex body structure
Cell wall presence
No cell wall present The cell wall is present
Organ system
The invertebrate organ system is not well defined and disorganized The vertebrate organ system is well established and organized
They have small sizes They vary in sizes from small to large
They belong to the Animalia kingdom They also belong to the Animalia kingdom
Invertebrates fall into “chordate” phyla. Vertebrates also fall on the phylum “chordates”
Types of eyes
They have compound eyes They do not have compound eyes
Layers of fur
They have only one layer of skin They have two layers of skin
Roundworms, tapeworms, sponges, and insects are examples of invertebrates. Birds, mammals, amphibians, and reptiles are an example of vertebrates
What are invertebrates?

Invertebratesare those animals that belong to the phylum “Animalia”; they do not have a backbone. The notochord does not develop in them. They have radial or bilateral body symmetry. They have a poorly organized nervous system. They are smaller than vertebrates. They move very slowly. They are multicellular organisms and most are found in colonies. They do not have a cell wall but they have many tissues, except sponges. They can move freely, but they move slowly. They feed on plants and other animals; therefore, they are known as heterotrophs. They are classified into 30 additional edges. They reproduce sexually. About 98% of the species of animals on earth are invertebrate animals. Approximately 2 million species of invertebrates are found on the planet’s surface. Its subphylum is vertebrata. They have no cracks. In invertebrates, the heart is located in the abdomen.


Sponges, coelenterates, echinoderms (starfish, sea urchin, sea cucumber), celebrations (ctenophore, comb jellies and sea feathers), mollusks, worms, cnidarians, worms are the example of invertebrates.

What are vertebrates?

VertebratesThey are those animals that have a firm backbone, they have an internal skeleton called the endoskeleton. Vertebrates are the most advanced organisms on this earth. Vertebrates have a developed nervous system, a digestive system, and a closed blood system. They have a segmented body and their bodies are more organized. They only have bilateral body symmetry. Vertebrates are more understanding because they have a well-developed brain. They are larger than invertebrates. They move faster than invertebrates. Vertebrates are further classified into five groups. They have a pharyngeal cleft to increase the efficiency of breathing. In vertebrates, the heart lies dorsally and the temperature of the blood is not the same as the temperature of the surrounding environment compared to invertebrates. They have no more than two pairs of limbs.


Examples of vertebrates are raptiles, amphibians, mammals, birds, marsupials, primates, rodents, cetaceans.

Key differences

  1. Invertebrates are animals without a notochord while vertebrates are those animals that have a notochord.
  2. Invertebrates do not have an organized organ system, but vertebrates have a well organized organ system.
  3. Invertebrate blood does not have red blood cells, but vertebrates have red blood cells that contain hemoglobin.
  4. In invertebrates, the eyes are actually a consequence of the skin, while in the case of vertebrates, the eyes are a consequence of the brain.
  5. All vertebrates have a hepatic portal system, while all invertebrates do not have a hepatic portal system.

Final Thought

Vertebrates and invertebrates are the two main groups of animals. The main difference is that vertebrates have a complex backbone, with an organized and larger organ system, while invertebrates are those animals that do not have a backbone, are simple, have a disorganized organ system and are more smaller than vertebrates.

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