Difference Between Coelomates and Pseudocoelomates


Main Difference

Just like humans the body of animals is also constituted of different parts and there are different terms which are used to explain the various body structures and two such words are coelom and pseudocoelomate which are used to describe the body cavities which exist in the animals. This article will help to understand the core difference between them and why they are separated from each other when they basically the same things. These cavities are present between the different layers which are called outer layers, inner layers, and middle coatings. These layers are also called ectoderm, endoderm and mesoderm respectively. These layers and formed with the help of embryo and the process named gastrulation and later on become and essential component of our body. Therefore, in simple words, coelom is the cavity which is present in the mesoderm while a pseudocoelomate is a cavity which is present between the mesoderm and endoderm and the only thing common between them is that they both are used in the animals. These types of animals are called coelomates and pseudocoelomates. Another difference between them Is that in pseudocoelomates the pseudo coelom is present as different entities while coelomates the coelom is present at one place. The best example for pseudo coelom is Aschelminthes while the example for coelom will be annelid, chordates and Arthropoda. Both these cavities become an important part of the human skeleton and keeps it safe from damage which can be caused in the form of applied stress and shocks. These components help in stopping the pressure and protecting the internal body parts. The structure and the position of both these cavities are different from each other as well, a coelom acts as a skeleton for the body while pseudo coelom does not do that because it is present on the outside of the body. To summarize, pseudocoelomates are the animals which lack a proper body cavity while coelomates are the animals which have an appropriate body cavity. More detail about both these types of cavities is given in the following paragraphs.

Comparison Chart

Animals which have a right body cavity are called coelomatesPseudocoelomates are animals which do not have a proper body cavity.
The cavity of the body which is present inside the body surfaceThe cavity which exists outside the surface.
Annelid, Chordates and Arthropoda.Aschelminthes
Exists between the mesoderm and endodermPresent inside the mesoderm.

Definition of Coelomates

Animals which have a body that includes voids are known as coelomates, they have a complete body structure, and their bodies are protected by coelom which acts as a body skeleton and saves all the internal organs from external stress. The coelom is formed at the stage known as gastrula, after different processes which include various functions the mesoderm is divided into two parts and coelom starts existing between them. The first layer is close to the body itself called endoderm while the other layer is at the outer side known as ectoderm. Therefore, coelom exists in the mesoderm which is the middle cavity. All these animals which are classified as coelomates are stronger as compared to others because their bodies are resistant to shocks and can withstand more pressure when they are under stress because of a fluid which is known as coelomic fluid and is the real part which becomes a hydroskeleton for the human body.


Definition of Pseudocoelomates

Animals which do not have a proper body cavity are known as pseudocoelomates. This is because of the reason that they have pseudo coelom which is present between the ectoderm and endoderm and lies outside the mesoderm. They are also scattered and present at more than one places, therefore, have a structure which does not seem similar to other species. Although it is a body cavity and functions properly but because of their nature, the fluid is not line properly but fills the body of animals, because of this the organs are placed close to each other in a scattered manner and therefore does not allow the body to form a proper skeleton. It does not protect the body at all and itself needs protection in different cases. The best example for pseudocoelomates are cnidarians which have two layers of tissues but do not have a coelom.

Differences in a Nutshell

  1. In simple terms both the term means the opposite of each other because of the addition of word pseudo which means false.
  2. Animals which have a right body cavity are called coelomates, but pseudocoelomates are animals which do not have a proper body cavity.
  3. Coelomate have the cavity of the body which is present inside the body surface while pseudocoelomates have the cavity which exists outside the surface.
  4. The body cavity is not lined up inside for pseudo coelom but for coelom the body cavities are lined inside.
  5. Examples of pseudocoelomate include Aschelminthes and the best example for coelomate are annelid, chordates and Arthropoda.
  6. Coelom supports the body parts along with it while pseudo coelom lacks the ability to do that.
  7. Coelom acts as a skeleton to protect the internal organs of the body, but pseudo coelom itself needs protection.
  8. Coelom is the body cavity which exists between the mesoderm and endoderm while pseudo coelom is the body cavity which is present inside the mesoderm.


Some terms are so difficult to pronounce, let alone understand. These couple of terms have been described in the article properly so that you can get to know about them without having to go into too much complexities. Overall, the details have been laid out to create a better understanding for a person who does not know about them.

Harlon Moss

Harlon currently works as a quality moderator and content writer for Difference Wiki. He graduated from the University of California in 2010 with a degree in Computer Science. Follow him on Twitter @HarlonMoss