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 major groups, one is the invertebrates, and the other one is vertebrates. Invertebrates are those animals that do not have a backbone, but vertebrates are those animals that have a healthy spine and internal skeleton of cartilage. Invertebrates animals are small in sizes because they do not have well-developed organ system that’s why their size remains small, but vertebrates include those animals who vary from little to larger because they have a more advanced organization of body structure. The invertebrates cover about 98% of the animal kingdom while vertebrates cover only 2%.


Comparison Chart

Animals without a backbone are called invertebratesAnimals with strong backbone are known as vertebrates
Symmetry of body
They have radial or bilateral body symmetryThey have only bilateral body symmetry
Body Structure
They have a simple body structureThey have a complex body structure
Presence of Cell wall
No cell wall is presentThe cell wall is present
Organ System
Organ system of invertebrates are not well defined and unorganizedOrgan system of vertebrates is well established and organized
They have small sizesThey vary in sizes from small to larger one
They belong to the Animalia kingdomThey also belong to the Animalia kingdom
Invertebrates fall in phyla “chordate.”Vertebrates also fall in “chordate” phylum
Types of Eyes
They have compound eyesThey do not have compound eyes
Skin Layers
They have only one layer of skinThey have two layers of skin
Roundworms, tapeworms, sponges, and insects are examples of invertebratesBirds, mammals, amphibians, and reptiles are an example of vertebrates

What are Invertebrates?

Invertebrates are those animals that belong to phylum “Animalia”; they do not have a backbone. The notochord is not developed in them. There have radial or bilateral body symmetry. They have a loosely organized nervous system. They are smaller in size than vertebrates. They move very slowly. They are multicellular organisms, and most are found in colonies. They have no cell wall but have many tissues, except in sponges. They can move freely, but they move slowly. They feed on plants and other animals; therefore they are known as heterotrophic. They are classified into further 30 phyla. They reproduce sexually. About 98% species of animals on earth are invertebrates animals.about 2 million species of invertebrates are found on the surface of the planet. Their subphylum is vertebrata. They have no clefts. In invertebrates, the heart is located in the abdomen. In invertebrates, blood temperature is the same as the temperature of the surrounding environment.they have more than two pairs of limbs — their skin consists of only one layer.


Sponges, coelenterate, echinoderms(starfish, sea urchin, sea cucumber), celebrates (ctenophore, comb jellies, and sea pens), mollusks, worms, cnidarians, worms are the example of invertebrates.


What are Vertebrates?

Vertebrates are those animals that have a firm backbone, have an internal skeleton which is called endoskeleton. Vertebrates are the more advanced organisms on this earth. Vertebrates have a developed nervous system, digestive system, and a closed blood system. They have a segmented body, and their bodies are more organized. They have only bilateral body symmetry. Vertebrates have more ability to understand because they have well-developed brain.they are bigger in size than invertebrates.they move faster than invertebrates. Vertebrates are further classified into five groups. They have pharyngeal cleft to increase the efficiency of breathing. In vertebrates, the heart is located dorsally, and the blood temperature is not the same as the temperature of the surrounding environment as compared to invertebrates.they do not have more than two pair of limbs. Vertebrates body have two layers of skin, one is epidermis and the second one is dermis.


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

Key Differences

  1. Invertebrates are animals without notochord while vertebrates are those animals who have a notochord.
  2. Invertebrates have no organized organ system, but vertebrates have well-organized organ system.
  3. Invertebrates blood do not have red blood cells, but vertebrates have red blood cells in their blood which contain hemoglobin.
  4. In invertebrates, eyes are actually the outgrowth of the skin, while in case of vertebrates, eyes are an outgrowth of the brain.
  5. All Vertebrates have a hepatic portal system, while all invertebrates do not have a hepatic portal system.


Vertebrates and invertebrates are the two major groups of animals. The main difference is, vertebrates have a backbone, complex, having organized organ system and larger in size, while invertebrates are those animals that have no backbone, simple, having unorganized organ system and smaller in size than vertebrates.

Janet White

Janet White is a writer and blogger for Difference Wiki since 2015. She has a master's degree in science and medical journalism from Boston University. Apart from work, she enjoys exercising, reading, and spending time with her friends and family. Connect with her on Twitter @Janet__White

Adblocker detected! Please consider reading this notice.

We've detected that you are using AdBlock Plus or some other adblocking software which is preventing the page from fully loading.

We don't have any banner, Flash, animation, obnoxious sound, or popup ad. We do not implement these annoying types of ads!

We need money to operate the site, and almost all of it comes from our online advertising.

Please add to your ad blocking whitelist or disable your adblocking software.