Difference Between Colonial and Filamentous Organisms

The main difference between colonial and filamentous organisms is that colonial organisms form a mass of similar cells while filamentous organisms form an array of organisms that resemble a filament. Moreover, colonial organisms appear as a sphere while filamentous organisms appear as a thread.

Colonial and filamentous organisms are unicellular or multicellular arrangements formed for mutualistic benefits. Each cell in the arrangement functions as a single unit and performs each and every target of a unicellular organism. Some colonial algae are Pandorina and Volvox while some filamentous algae are Spirogyra and Zygnema.  

Key Areas Covered 

1. What are Colonial Organisms
     – Definition, Structure, Examples
2. What are Filamentous Organisms
     – Definition, Structure, Examples
3. What are the Similarities Between Colonial and Filamentous Organisms
     – Outline of Common Features
4. What is the Difference Between Colonial and Filamentous Organisms
     – Comparison of Key Differences

Key Terms: Algae, Colonial Organisms, Filamentous Organisms 

What are Colonial Organisms 

Colonial organisms refer to a group of organisms in a colony with close contact with each other. It is a result of multiple cell divisions. Hence, each organism consists of the same genome. The main purpose of colonial organisms is mutual benefits such as food access and security. Some examples of unicellular colonial organisms that are unicellular algae are diatomaceous, euglenoid, dinoflagellate, blue-green, green, golden-brown, and yellow-green algae. The two types of spores that form colonial organisms are the zoospores and autospores.

Figure 1: Colonial Tube Sponge 

Marine invertebrates and lower chordates are multicellular colonial organisms. Hydrozoans, sponges, coral, and coelenterates are colonial invertebrates. Doliolidae, Synascidiaepyrosomata, and salps are lower chordates that form colonies. Multicellular colonial organisms are often called ramets, zooids or modules.  

What are Filamentous Organisms 

Filamentous organisms form an end to end arrangement as they undergo binary fission. Actinomycetes are the filamentous form of bacteria. Filamentous algae form visible thread-like structures. The intertwining of the filaments forms a mat-like structure that resembles a wet wool. These mat-like structures are either attached to a structure or float on the water surface. The floating large mats are called pond scums. Generally, filamentous algae are a type of primary producers in aquatic food chains.

Figure 2: Filamentous Algae 

Filamentous fungi are multicellular organisms that show filamentous growth. The filamentous structures of fungi are called the hyphae. Mycelium is a collection of hyphae. Molds are the fungi that form mycelium. 

Similarities Between Colonial and Filamentous Organisms 

• Colonial and filamentous organisms are multicellular arrangements. 
• The cells in both arrangements have the same genome. 
• Both unicellular and multicellular organisms can form these arrangements. 
• The cells divide by mitosis to form both arrangements. 
• Each arrangement consists of individual units, performing each and every function in a cell.  
• Both lack a division of labor.  

Difference Between Colonial and Filamentous Organisms 

Definition 

Colonial organisms refer to a group of individual organisms with a close dependent relationship with other organisms in the colony while filamentous organisms refer to organisms that form a filamentous growth.  

Type of Arrangement 

Colonial organisms form a spherical mass of cells while filamentous organisms form an array of cells with an end to end arrangement. This is the main difference between colonial and filamentous organisms,

Appearance 

Colonial organisms appear as a sphere while filamentous organisms appear as a thread.  

Cell Division 

Colonial organisms are a result of multiple cell divisions by mitosis while filamentous organisms are a result of multiple binary fission.  

Intercellular Wall 

The cells in the colonial arrangement lack an intercellular cell wall while the cells in the filamentous arrangement have an intercellular wall.  

Types of Organisms 

Colonial Organisms are bacteria, algae, marine invertebrates, and lower chordates while filamentous organisms are bacteria. fungi, and algae. 

Sessile or Floating 

Colonial organisms are generally sessile while filamentous organisms are either sessile or floating.

Conclusion 

Colonial organisms form a spherical cell mass while filamentous organisms form a thread-like structure by end to end arrangements of cells. Both unicellular and multicellular organisms can form both types of arrangements. The main difference between colonial and filamentous organisms is the type of cellular arrangements. 

Reference:

1. “Colonial Organisms.” The Free Dictionary, Farlex, Available Here.
2. “Filamentous Algae « AQUAPLANT.” AQUAPLANT, Available Here.
3. “Filamentous Fungi.” The Free Dictionary, Farlex, Available Here.

Image Courtesy:

1. “Colonial tube-sponge (Callyspongia siphonella) (10069315045)” By Tim Sheerman-Chase – Colonial tube-sponge (CC BY 2.0) via Commons Wikimedia         
2. “Young Aquatic fungus champignonAquatique à lamelles Moyenne-Deûle 2015 F.Lamiot 09” By Lamiot – Own work (CC BY-SA 4.0) via Commons Wkimedia