What is the Difference Between Schizocoelous and Enterocoelous

The main difference between schizocoelous and enterocoelous is that schizocoelous is the condition in which the coelom and mesoderm initially develop from a solid block of mesoderm tissue whereas enterocoelous is the condition in which the coelom and mesoderm initially develop as a pocket of the primitive gut. 

Schizocoelous and enterocoelus are two mechanisms of coelom development in animals. Development of coelom in protostomes is schizocoelous while the development of coelom in deuterostomes is enterocoelous.

Key Areas Covered

1. What is Schizocoelous
     – Definition, Development of Coelom, Occurrence
2. What is Enterocoelous
     – Definition, Development of Coelom, Occurrence
3. What are the Similarities Between Schizocoelous and Enterocoelous
     – Outline of Common Features
4. What is the Difference Between Schizocoelous and Enterocoelous
     – Comparison of Key Differences

Key Terms

Coelom, Deuterostomes, Enterocoelous, Protostomes, Schizocoelous

What is Schizocoelous

Schizocoelous or schizocoely is the formation of coelom by splitting the mesodermal embryonic tissue. Generally, coelom is the body cavity that lays between the musculature of the body wall and the digestive tract. In schizocoely, mesoderm, which is the middle germ layer formed during the embryonic development, splits to form the coelom.

Figure 1: Coelom

Furthermore, the term schizocoelomates refer to the animals formed by schizocoely. Also, the three main phyla that include schizocoelomates are Mollusca, Annelida, and Arthropoda. Generally, protostomes are schizocoelomates. The main feature of protostomes is the development of blastophore into the mouth.

What is Enterocoelous

Enterocoelous or enterocoely is the formation of coelom from pouches “pinched” off of the digestive tract or archenteron. During the gastrula phase of the embryonic development, the third germ layer begins to develop as two “pockets” of tissue above and below of the endoderm, folding the endoderm. Then, the two pockets grow larger, extending towards each other. Once they meet, mesoderm is formed between the endoderm and ectoderm. Then, the formation of mesoderm leads to the formation of the coelom.

Figure 2: The Development of Protostomes and Deuterostomes

Moreover, the term enterocoelomates refer to the animals formed by enterocoely. Generally, enterocoelomates are deuterostomes whose blastophore develops into the anus. The three clades of deuterostomes are Chordata, Hemichordata, and Echinodermata.

Similarities Between Schizocoelous and Enterocoelous

• Schizocoelous and enterocoelous are two conditions of embryonic development in animals.
• They describe the process of the development of the coelom and mesoderm.
• Different types of coelom and mesoderm development give rise to different forms of animals.
• However, all animals in both groups have bilateral symmetry and develop three germ layers.
• Also, both types of developments occur in the gastrula phase of the embryo.

Difference Between Schizocoelous and Enterocoelous

Definition

Schizocoelous refers to the condition of embryonic development in which the body cavity is formed by the splitting of the mesoderm while enterocoelous refers to the condition in which the coelom forms from pouches “pinched” off of the digestive tract. Thus, this is the main difference between schizocoelous and enterocoelous.

Significance

Importantly, coelom begins as splits within the solid mesodermal mass in schizocoelous animals while mesoderm arises as lateral out-pocketing of archenteron with hollows that become the coelomic cavity in enterocoelous animals. Hence, this is another difference between schizocoelous and enterocoelous.

Type of Cleavage

Also, an important difference between schizocoelous and enterocoelous is that the cleavage of schizocoelous animals is holoblastic, spiral and determinate while the cleavage of enterocoelous animals is radial and indeterminate.

Occurrence

Moreover, another difference between schizocoelous and enterocoelous is that the development of coelom in protostomes is schizocoelous while the development of coelom in deuterostomes is enterocoelous.

Examples

Annelids, arthropods, and mollusks are schizocoelous while echinoderms, hemichordate, and chordates are enterocoelus.

Conclusion

Svhizocoelous is the condition in which the coelom is formed by splitting the mesoderm. It occurs in protostomes. On the other hand, enterocoelous is the condition in which the coelom is formed from the mesodermal pouches of archenteron. It occurs in deuterostomes. Therefore, the main difference between schizocoelous and enterocoelous is the origin of the coelom.

Reference:

1. “Schizocoelomate.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 26 Nov. 2008, Available Here.
2. “Enterocoelomate.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 7 Nov. 2008, Available Here.

Image Courtesy:

1. “Coelomate 01” By Philcha (talk) – Own work (Original text: I created this work entirely by myself.) (Public Domain) via Commons Wikimedia   
2. “Protovsdeuterostomes” By WYassineMrabetTalk This W3C-unspecified vector image was created with Inkscape. – Own work (CC BY-SA 3.0) via Commons Wikimedia