Key Difference – Schizocoelous vs Enterocoelous
The key difference between Schizocoelus organisms and Enterocoelus organisms is the manner in which their embryo development takes place. In Schizocoelus organisms, coelom develops by splitting of the mesodermal embryonic tissue. In Enteroceolus organisms, the coelom is formed by the pouches formed by the digestive tract.
CONTENTS
1. Overview and Key Difference
2. What is Schizocoelous
3. What is Enterocoelous
4. Similarities Between Schizocoelous and Enterocoelous
5. Side by Side Comparison – Schizocoelous vs Enterocoelous in Tabular Form
6. Summary
What is Schizocoelous?
Schizocoelus organisms typically belong to the protostomes that include the phyla Mollusca, Annelida and Arthropoda. Schizocoelus or Schizocoelyis the process in which these animals of the above-mentioned phyla undergo embryonic development. These organisms are thus termed as schizocoelomates. Schizocoelus thus refers to the process in which the body cavity or the coelom is formed by the splitting of the mesodermal embryonic tissue.
Schizocoely occurs after the gastrula formation. The mesoderm forms a single lining of solid cells on the lining of the gastrula. Then it splits giving rise to the body cavity or the coelom. The mesoderm is formed as a result of the interaction between the cells of the ectoderm and the endoderm. Thus, in summary, the splitting of the middle layer, which is the mesoderm gives rise to the coelom of protostomes.
What is Enterocoelous?
Enterocoelous or enterocoely is observed in deuterostomes, and thus they are known as enterocoelomates. Chordates and echinodermates belong to the category of enterocoelous organisms. This is one form of embryonic development. During enterocoelus development, the organism’s mesoderm is formed from the developing embryo. From the mesoderm, pouches are pinched off the digestive tract thus, forming the coelom. The digestive tract is also referred to as the embryonic gut or the archenteron in this phenomenon.
Figure 01: Enterocoelous
Entercoelous development takes place upon completion of the gastrula phase of embryonic development. During enterocoelous development, the ectoderm and the endoderm interact to form the mesoderm. The formation of the mesoderm begins as pockets that grow larger leading to the formation of the coelom.
What are the Similarities Between Schizocoelous and Enterocoelous?
- Both schizocoelus and enterocoelus represent the forms of embryonic development.
- Both processes are initiated after the gastrula development.
- Both processes lead to the formation of the true coelom.
- Both processes require the formation of the mesoderm via the interaction between the ectoderm and the endoderm.
What is the Difference Between Schizocoelous and Enterocoelous?
Schizocoelous vs Enterocoelous |
|
| In Schizocoelus organisms, the embryo is developed by schizocoely – coelom is formed by splitting of the mesodermal embryonic tissue. | In Enteroceolus organisms, the body cavity is formed by enterocoely – the coelom is formed by the pouches formed by the digestive tract. |
| Formation of the Coelom | |
| The coelom is formed by the splitting of the mesoderm in schizocoelous. | The coelom is formed by the formation of the pouches from the digestive tract or the archenteron in enterocoelous. |
| Cleavage | |
| Holoblastic, spiral and determinate cleavage of mesodermal tissue occur in schizocoelous. | Radial and indeterminate cleavage occur in enterocoelous. |
| Involvement of the Digestive Track or the Archenteron | |
| Digestive tract is not involved in schizocoelous. | Digestive tract is involved in enterocoelous. |
| Formation of Pouches during the Coelom Formation | |
| Pouches are not formed from digestive tract in schizocoelous. | Pouches are formed from digestive tract in enterocoelous. |
| Formation of Masses of Mesoderm Split | |
| Mesoderm splits in schizocoelous organisms. | Mesoderm does not split in enterocoelous organisms. |
| Type of Organism | |
| Protostomes are schizocoelous. | Deuterostomes are enterocoelous. |
| Example | |
| Organisms belonging to Phyla Annelida, Mollusca and arthropoda are schizocoelous. | Organisms belonging to the Phyla Echinodermata and Chordata are enterocoelous. |
Summary – Schizocoelous vs Enterocoelous
Both concepts, Schizocoelous and Enterocoelous describe the manner in which embryonic development takes place following the gastrula formation. In Schizocoelous organisms, the mesodermal tissue is cleaved to form the coelom or the body cavity. In Entercoelous organisms, pouches are formed from the mesoderm on the digestive tract. Upon fusion of these pouches, the coelom is formed. Thus, the group referred to as Protostomes belong to the Schizocoelus and the group referred to as the Deuterostomes are Enterocoelous in nature. This is the difference between Schizocoelous and Enterocoelous.
Reference:
1.“An Introduction to Zoology: Chapter 4 – Freethought Forum.” Freethought Forum RSS. Available here
2.Gilbert, Scott F. “Developmental Patterns among the Metazoa.” Developmental Biology. 6th Edition., U.S. National Library of Medicine, 1 Jan. 1970. Available here
Image Courtesy:
1.’Deuterostomia’By WYassineMrabetTalk (CC BY-SA 3.0) via Commons Wikimedia