If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

Echinodermata, Hemichordata, and Chordata

Problem

A. heterolopha is a species with the following characteristics.
  • It has a stomochord.
  • It has an open circulatory system.
  • It is a cylindrical animal.
  • It uses gill slits for respiration.
Under which group of animals would you categorize A. heterolopha?
Choose 1 answer: