planula

noun, plural plan·u·lae [plan-yuh-lee] /ˈplæn yəˌli/. Zoology.

1. the ciliate, free-swimming larva of a coelenterate.

noun plural -lae (-ˌliː)

1. the ciliated free-swimming larva of hydrozoan coelenterates such as the hydra

Plural planulae (plăn′yə-lē′)

1. The flat, free-swimming, ciliated larva of a cnidarian.