What is the Difference Between Mesoglea in Cnidarians and Mesohyl in Poriferans

The main difference between mesoglea in cnidarians and mesohyl in poriferans is that mesoglea in cnidarians mainly composes of water and several substances including fibrous proteins, like collagen and heparan sulfate proteoglycans, whereas mesohyl in poriferans is a gelatinous matrix, mainly composing of collagen, fibronectin-like molecules, galectin, and dermatopontin as the minor component. Furthermore, mesoglea in cnidarians is mainly acellular although it contains muscle bundles and nerve fibers. In contrast, mesohyl in poriferans is mainly cellular, containing amebocytes. Moreover, mesoglea in cnidarians serves as a hydrostatic skeleton, but mesohyl in poriferans provides the platform for specific cell adhesion, and as well as for signal transduction and cellular growth.  

In brief, mesoglea in cnidarians and mesohyl in poriferans are two types of matrices, which fill the middle layer of the body wall. Importantly, the basic function of them is to provide support to the body. 

Key Areas Covered 

1. What is Mesoglea in Cnidarians
     – Definition, Structure, Function
2. What is Mesohyl in Poriferans
     – Definition, Structure, Function
3. What are the Similarities Between Mesoglea in Cnidarians and Mesohyl in Poriferans
     – Outline of Common Features
4. What is the Difference Between Mesoglea in Cnidarians and Mesohyl in Poriferans
     – Comparison of Key Differences

Key Terms 

Connective Tissue, Internal Skeleton, Mesoglea in Cnidarians, Mesohyl in Poriferans

What is Mesoglea in Cnidarians 

Mesoglea in cnidarians is the connective tissue layer, occurring between the two epithelia of the body wall. It mainly contains water. Also, it contains fibrous proteins such as collagen and heparan sulfate proteoglycans. In addition to these, mesoglea also contains nerve fibers and muscle fibers. Furthermore, mesoglea is thinner and around one cell thick. 

Figure 1: Cnidarian Body Structure

Concerning the functions, the main function of mesoglea in cnidarians is to serve as an internal skeleton, which is hydrostatic. Also, the elastic properties of the mesoglea help to restore the deformed body structure due to muscular contractions. Besides, the buoyancy of water plays an important role in bearing bodyweight of cnidarians, preventing them to flatten out.  

What is Mesohyl in Poriferans 

Mesohyl in poriferans is the connective tissue layer, occurring between the external pinacoderm and the internal choanoderm. It is a gelatinous matrix with fibrils and skeletal elements. Also, collagen, fibronectin-like molecules, and galectin are the main components of the mesohyl, while dermatoponin is the minor component of it. However, mesohyl can be considered as the noncellular colloidal mesoglea with embedded collagen fibers, spicules, and various cells.

Figure 2: Porifera Body Structure

Considering its functions, the main function of mesohyl is also to provide structural support to the body of poriferans. Also, the peptidoglycans of the matrix provide a platform for the adhesion of cells, signal transduction, and cell growth. Apart from that, mesohyl bears some ameboid cells such as amebocytes that phagocytose bacteria and other debris. 

Similarities Between Mesoglea in Cnidarians and Mesohyl in Poriferans 

• Mesoglea in cnidarians and mesohyl in poriferans are two types of connective tissues, which occur between the two epithelium. 
• Generally, they contain collagen and other skeletal elements in the matrix. 
• The main function of them is to support the body structure. 

Difference Between Mesoglea in Cnidarians and Mesohyl in Poriferans 

Definition 

Mesoglea in cnidarians refers to the tissue found in jellyfish that functions as a hydrostatic skeleton. But, on the other hand, mesohyl in poriferans refers to the gelatinous matrix within a sponge, filling the space between the external pinacoderm and the internal choanoderm.  

Components 

Also, mesoglea in cnidarians mainly composes of water and several substances, including fibrous proteins, like collagen and heparan sulfate proteoglycans. But, mesohyl in poriferans is a gelatinous matrix, which mainly composes of collagen, fibronectin-like molecules, galectin, and dermatopontin as the minor component.  

Cellular Components 

Moreover, mesoglea in cnidarians is mainly acellular although it contains muscle bundles and nerve fibers. But, in contrast, mesohyl in poriferans is mainly cellular, containing amebocytes.  

Function 

Besides these, another difference between both is that mesoglea in cnidarians serves as a hydrostatic skeleton, while mesohyl in poriferans provides the platform for specific cell adhesion, as well as for signal transduction and cellular growth.  

Conclusion 

Mesoglea in cnidarians is the connective tissue, which occurs between the two layers of the epithelium. It mainly composes of water. Also, it contains collagen and heparan sulfate proteoglycans. In addition to these, it contains muscle bundles and nerve fibers. On the other hand, mesohyl in poriferans is the gelatinous matrix, which occurs as the middle layer of the body wall. It includes a noncellular colloidal mesoglea with embedded collagen fibers, spicules, and various cells. Functionally, the main function of the mesoglea is to serve as a hydrostatic skeleton while mesohyl is important for cell adhesion, signal transduction, and cellular growth. Therefore, the main difference between mesoglea in cnidarians and mesohyl in poriferans is their components and functions. 

References:

1. “Mesoglea.” Wikipedia, Wikimedia Foundation, 3 July 2019, Available Here.
2. “Mesohyl.” Wikipedia, Wikimedia Foundation, 12 Oct. 2019, Available Here.

Image Courtesy:

1. “Cross section Olindias formosa en” By Mariana Ruiz Villarreal (LadyofHats) (Public Domain) via Commons Wikimedia   
2. “Porifera body structures 01” By Philcha – Own work (CC BY-SA 3.0) via Commons Wikimedia