Difference Between Phylum Annelida and Echinodermata

The key difference between phylum Annelida and Echinodermata is that phylum Annelida includes segmented worms that show bilateral symmetry while phylum Echinodermata includes organisms that show pentamerous radial symmetry.

All animals come under the Kingdom Animalia. Therefore, it comprises many different types of multicellular animals. Also, there are different major phyla in the Kingdom Animalia. Among them, Phylum Annelida and Phylum Echinodermata are non-chordate phyla. Both phyla consist of invertebrate species with great diversity.

CONTENTS

1. Overview and Key Difference
2. What is Phylum Annelida 
3. What is Phylum Echinodermata
4. Similarities Between Phylum Annelida and Echinodermata
5. Side by Side Comparison – Phylum Annelida vs Echinodermata in Tabular Form
6. Summary

What is Phylum Annelida?

Phylum Annelida consists of segmented worms with true coeloms. These organisms 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.

There are three different classes of phylum Annelida based on the presence or absence of parapodia and setae. Accordingly, the three classes of annelids are class Polychaeta, which includes sea worms, class Oligochaeta, which includes earthworms, and class Hirudinea, which includes leeches.

What is Phylum Echinodermata?

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. Moreover, the unique features of Echinodermata are the 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: Asteroidea (e.g. starfish), class Ophiuroidea (e.g. brittle stars), class Echinoidea (e.g. sea urchins), class Holothuroidea (e.g. sea cucumbers), and class Crinoidea (e.g. sea feather). In all of them, the tube feet are used as locomotors.

What are the Similarities Between Phylum Annelida and Echinodermata?

• Phylum Annelida and phylum Echinodermata are two phyla of Kingdom Animalia.
• Both these phyla include invertebrates.
• Also, both are non-chordates.
• Moreover, they are coelomates.

What is the Difference Between Phylum Annelida and Echinodermata?

Phylum annelid includes segmented worms that show bilateral symmetry. In contrast, phylum Echinodermata includes organisms that show pentamerous radial symmetry. Therefore, this is the key difference between phylum Annelida and Echinodermata. Furthermore, annelids are true coelomates while Echinodermata are enterocoelomates. So, this also a significant difference between phylum Annelida and Echinodermata.

Moreover, a further difference between phylum Annelida and Echinodermata is their habitat. Annelids are found in both terrestrial and aquatic habitats while echinoderms are found only in marine habitats.

The below info-graphic presents more information on the difference between phylum Annelida and Echinodermata.

Summary – Phylum Annelida vs Echinodermata

In brief, Phylum Annelida and phylum Echinodermata are two phyla of kingdom Animalia. Both phyla include invertebrates that are non-chordates. Phylum annelid includes bilaterally symmetrical segmented worms while phylum Echinodermata includes radially symmetrical marine organisms. Echinoderms are more advanced than annelids. Moreover, they have a complex body structure, and they are very closer to chordates. Furthermore, echinoderms can regenerate while annelids cannot. Thus, this is the summary of difference between phylum Annelid and Echinodermata.

Reference:

1. Pawson, David Leo, and John E. Miller. “Echinoderm.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 12 Sept. 2016, Available here.
2. Reish, Donald J. “Annelid.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 18 Dec. 2013, Available here.

Image Courtesy:

1. ” A monograph of the British marine annelids 1908 XLVII” By Roberta MacIntosh – (Public Domain) via Commons Wikimedia
2. “Echinoderms of Connecticut (1912) (21147084391)” By Coe, Wesley Roswell, 1869-1960 – (No restrictions) via Commons Wikimedia