Annelids room segmented worms conversely, roundworms room not segmented. Further, annelids have a true coelom while roundworms have a pseudocoelom. This means annelids have a well-developed mesoderm if roundworms absence a mesoderm.

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These are the main features that distinguish annelids indigenous roundworms.

Annelids and roundworms space invertebrates through elongated bodies. Both exhibit bilateral symmetry. They have a complete digestive system.

Key areas Covered 

1. Annelids Definition, Taxonomy, Characteristics 2. Roundworms Definition, Taxonomy, Characteristics 3. What space the Similarities between Annelids and Roundworms Outline of common Features 4. What Features differentiate Annelids indigenous Roundworms Comparison of key Differences

Key Terms

Annelids, human body Cavity, Roundworms, Segmentation


Annelids – Definition, Taxonomy, Characteristics 

Annelids room segmented worms that belong come the phylum Annelida. They are the most facility form that worms. Most annelids are beneficial but, some deserve to be parasitic.


Figure 1: an annelid

The three classes of annelids space Polychaeta (bristle worms), Oligochaeta (earthworms), and Hirudinea (leeches). Bristle worms are the largest group of annelids that largely live in naval habitats. Earthworms space terrestrial members. Leeches room parasitic members the annelids.

Roundworms – Definition, Taxonomy, Characteristics 

Roundworms space cylindrical worms whose body is tapered at both ends. Castle belong to the phylum Nematoda. Castle are mostly parasitic, living inside plants and animals. On that account, their body surface is composed of ridges, warts, and also rings.


Figure 2: Roundworms

The three classes of roundworms are Enoplea (enopleans), Dorylaimida (dorylaims), and Secernentea (secernenteans). Dorylaims live in soil or freshwater. Both enopleans and Secernenteans are helminth of plants and animals consisting of humans.

Similarities between Annelids and Roundworms 

Annelids and roundworms room invertebrates v an elongated body. They have a bilateral symmetry. Both have a finish digestive system. They have the right to be either free-living or helminth in plants and animals. 

What Features distinguish Annelids native Roundworms

Segmentation – Annelids have a segmented body while the body of roundworms is not segmented. These segments are the repeating sections the collectively type the human body of annelids. Each section is composed of a separate collection of inner organs. However, annelids have a blunt-ended body while roundworms have tapered end in your body. 

Mesoderm and also Coelom – Annelids have actually a well-developed mesoderm while roundworms execute not have a mesoderm. So, annelids may have actually a true coelom when roundworms may have actually a pseudocoelom. In addition, the guts of the annelids space separated indigenous the coelomic fluid, while in roundworms, organs swimming in the fluid of the coelom. 

Body Structure – Annelids are worms with the most complex body plan while roundworms have actually a medium complicated body. Also, annelids room 8-10 inches long while roundworms can more than 4 feet long. Furthermore, annelids have a complete circulatory system with a heart, blood vessels, and blood when roundworms perform not have actually a circulatory system and also the nutrients move through diffusion. Moreover, annelids have both longitudinal muscles and circular muscles while roundworms only have actually longitudinal muscles. However, annelids have eyespots if roundworms have actually more complex eyes 보다 annelids. Also, roundworms have a rigid cuticle made up of collagen in your epidermis.

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Feeding – many annelids live inside the soil. They feeding on main detritus and other decaying organic matter. Also, this annelids help in the aeration of the soil. On the various other hand, most roundworms are parasites in plants and also animals including humans. 


Annelids room the most complex worms v a segmented body. On the other hand, roundworms have a cylindrical body v tapered ends. Most annelids are valuable while roundworms space infectious. These space the features that differentiate annelids native roundworms.


1. “Worms: Phyla Platyhelmintes, Nematoda, and also Annelida.” Exploring Our fluid Earth, Kaunana, Available right here

Image Courtesy:

1. “Annelid worm, Atlantic forest, north littoral that Bahia, Brazil (16107326533)” by Alex Popovkin, Bahia, Brazil (CC by 2.0) via Commons Wikimedia 2. “Toxocara-canis-adults” by Alan R pedestrian – Own occupational (CC BY-SA 3.0) via Commons Wikimedia