What is the Difference Between Hemichordata and Chordata?

Hemichordata and Chordata are two distinct phyla within the kingdom Animalia. They share some common characteristics but also have several key differences:

1. Nervous System: Hemichordata possesses an epidermal nervous system, while Chordata possesses a central nervous system.
2. Notochord: The notochord is present in Chordata but absent in Hemichordata.
3. Circulatory System: Hemichordata has an open circulatory system, while Chordata has a closed circulatory system.
4. Post-Anal Tail: Hemichordata lacks a post-anal tail, while Chordata has one.
5. Habitat: All Hemichordata species are marine, while Chordata includes both terrestrial and aquatic animals.

Some common features between the two phyla include:

• Both groups are coelomates.
• Both Hemichordata and Chordata contain pharyngeal gill slits.
• Both groups are closely related and show a similar body plan with bilateral symmetry.

In summary, Hemichordata and Chordata are two distinct phyla with some shared characteristics, but they differ in terms of their nervous system, presence of a notochord, circulatory system, and presence of a post-anal tail.

Comparative Table: Hemichordata vs Chordata

Here is a table that highlights the differences between Hemichordata and Chordata:

Hemichordata and Chordata are both deuterostome phyla, meaning they share a common ancestor and are closely related. Hemichordates are worm-like marine animals, while chordates live in water, land, and air. The main difference between Hemichordata and Chordata is the presence of a notochord and the type of nervous system. Hemichordates possess an epidermal nervous system, while Chordates have a dorsal, tubular nerve cord.