1. Marine animals with a sac-like body, a notochord in the larval stage, and gill slits; members of the class Ascidiacea.
Usage: plural of ascidian; biology/zoology term; also called sea squirts

Examples

• Ascidians are found attached to rocks and coral reefs in ocean environments.
• The larvae of ascidians have a notochord that disappears in the adult form.
• Scientists study ascidians because they are early chordates in evolutionary history.
• Many ascidians filter feed by drawing water through their bodies.
• Ascidians can reproduce both sexually and asexually through budding.
• The transparent bodies of some ascidians make them useful for developmental research.