Difference Between Phylum Annelida and Echinodermata

Phylum Annelida vs Echinodermata

If you are interested in getting to know different species, it will be useful for you to know the difference between phylum annelida and echinodermata. Phylum Annelida and Phylum Echinodermata are nonchordate phylathat come under Kingdom Animalia. Both phyla consist of invertebrate species with great diversity.

What is Phylum Annelida (Annelids)?

Phylum Annelida is composed of segmented worms with true coeloms. In addition, they are triploblastic and show bilateral symmetry. Annelids have tube-like bodies with simple organ systems including straight alimentary canal, nephridia, closed circulatory system, double ventral nerve cord. Annelids are classified according to the presence or absence of parapodia and setae. Accordingly, the three Classes of Annelids are, (i) Class Polychaeta, which includes sea worms, (ii) Class Oligochaeta, which includes earthworms, and (iii) Class Hirudinea, which includes leeches.

Difference Between Phylum Annelida and Phylum Echinodermata

What is Phylum  Echinodermata (Echinoderms)?

All the species of Phylum Echinodermata show pentamerous radial symmetry, especially in adults, while their larvae show bilateral symmetry. All the members are exclusively marine and able to regenerate their body parts. The unique features of echinodermata are presence of spiny skin, short oral- aboral axis, tube feet, water vascular system, and endoskeleton made up of dermal plates. In addition to these features, echinoderms have noticeable ambulacral and inter-ambulacral areas. The phylum has five classes. They are Class Asteroidea (ex: starfish), Class Ophiuroidea (ex: brittle stars), Class Echinoidea (ex: sea urchins), Class Holothuroidea (ex: sea cucumbers), and Class Crinoidea (ex: sea feather). The tube feet are used as locomotors.


What is the difference between Phylum Annelida and Echinodermata?

• Echinoderms are enterocoelomates, whereas annelids are true coelomates.

• Echinoderms show bilateral symmetry (larvae) and characteristic pentamerous radial symmetry (adults), whereas annelids show only bilateral symmetry.

• Phylum Annelida includes segmented worms such as earthworms, leeches, etc. whereas Phylum Echinodermata include s starfishes, sea-urchins, sea cucumbers, sea feathers and brittle stars.

• Unlike annelids, echinoderms are closer species to chordates.

• Phylum Annelida includes three Classes, while Phylum Echinodermata includes five Classes.

• Echinoderms are found only in marine habitats, whereas annelids are found in both terrestrial and aquatic habitats.

• Annelids use longitudinal and circular muscles mainly for locomotion, whereas echinoderms use tube feet for locomotion.

• Annelids have more simple body structures when compared to echinoderms.

• Echinoderms can regenerate body parts, unlike annelids.


Further Reading:

  1. Difference Between Nematodes and Annelids
  2. Difference Between Arthropods and Annelids
  3. Difference Between Chordates and Echinoderms 
Image of Echinoderms By Veronidae (CC BY-SA 2.5)