Found 2 items, similar to planula.
English → English (WordNet) Definition: planula planula n : the flat ciliated free-swimming larva of hydrozoan coelenterates [also: planulae (pl)]
English → English (gcide) Definition: Planula Planula \Plan"u*la\, n.; pl. Planul[ae]. [L., a little plane.] 1. (Biol.) In embryonic development, a vesicle filled with fluid, formed from the morula by the divergence of its cells in such a manner as to give rise to a central space, around which the cells arrange themselves as an envelope; an embryonic form intermediate between the morula and gastrula. Sometimes used as synonymous with gastrula. [1913 Webster] 2. (Zo["o]l.) The very young, free-swimming larva of the c[oe]lenterates. It usually has a flattened oval or oblong form, and is entirely covered with cilia. [1913 Webster]