While trying to find out the characteristic of a newlyfound animal, a researcher did the histology of adultanimal and observed a cavity with presence ofmesodermal tissue towards the body wall but nomesodermal tissue was observed towards thealimentary canal. What could be the possiblecoelome of that animal?

Answer

Pseudocoelom and Body Cavity Organization in Certain Animals

In the animal kingdom, the structure and organization of the body cavity, or coelom, is an important criterion for classification. In some animals, this body cavity is not fully lined by mesoderm, giving rise to a condition known as a pseudocoelom.

Pseudocoelomate Condition

In pseudocoelomates, the body cavity—termed the pseudocoel—is only partially lined with mesoderm. Here are the key characteristics:

• The mesoderm exists as scattered pouches between the ectoderm (outer layer) and endoderm (inner layer).
• It generally lines only the body wall (next to the ectoderm) and does not surround the alimentary canal.
• This results in a less complex internal organization compared to true coelomates.

Example: Phylum Aschelminthes

Members of the phylum Aschelminthes, such as roundworms, exhibit this body cavity structure. These animals:

• Possess a fluid-filled pseudocoelom
• Lack a complete mesodermal lining around internal organs
• Utilize the pseudocoel for basic nutrient transport and as a hydrostatic skeleton