Question

compare Platyhelminthes nematoda and Annelida

Answer 1

The main difference between Nematoda and Annelida is that Nematoda has a cylindrical body with tapered ends whereas Annelida has a cylindrical body, which is segmented. Therefore, Nematoda is called roundworms while Annelida is called segmented worms. Furthermore, Nematoda has a pseudocoelom while Annelida has a truecoelom.  

Nematoda and Annelida are two animal phyla that consist of invertebrates with elongated bodies. Most Nematodes are parasites in plants or animals while most annelids are free-living in the soil.  

Nematoda and Annelida 

Definition 

Nematoda refers to an animal phylum of worms with slender, unsegmented, cylindrical bodies with tapered ends found abundantly in soil and water while Annelida refers to an animal phylum that comprises cylindrical bodied, segmented worms. This is the main difference between nematoda and annelida.

Commonly Called 

Nematoda is called roundworms while Annelida is called segmented worms. 

Complexity 

Nematoda has a medium complex body while Annelida is the group with the most complex body plan among other worms. 

Mesoderm 

Nematodes do not have a mesoderm while annelids have a well-developed mesoderm. 

Coelom 

Nematodes have a pseudocoelom while annelids have a true coelom.  

Organs 

The organs of the nematodes are bathed in the fluid of the body cavity while the organs of the annelids are separated from the coelom cavity.  

Body Segment 

Nematodes have an unsegmented body while annelids have a segmented body.  

Tapered Ends 

Nematodes have tapered body ends while annelids do not have tapered ends in their body.  

Body Length 

Nematodes can be over 4 feet long while annelids are 8-10 inches long.  

Circulatory System 

Nematodes do not have a circulatory system and the nutrients move through diffusion while annelids have a complete circulatory system with a heart, blood vessels, and blood.  

Muscles  

Nematodes only have longitudinal muscles while annelids have both longitudinal muscles and circular muscles. 

Eyes 

Nematodes have more complex eyes than annelids while annelids have eyespots.  

Cuticle 

Nematodes have a rigid cuticle made up of collagen while annelids do not have a cuticle.  

Reproduction 

Nematodes have separated sexes while annelids are hermaphrodites.  

Importance 

Most nematodes are parasites that cause severe infections while most annelids live in the soil and they aid in the aeration of the soil.  

Answer 2

Nematodes have a rigid cuticle made up of collagen while annelids do no have a cuticle