planula Meaning, Definition & Usage

  1. noun the flat ciliated free-swimming larva of hydrozoan coelenterates

WordNet


Plan"u*la noun
Etymology
L., a little plane.
Wordforms
plural Planulæ
Definitions
  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. now usu. gastrula
  2. (Zoöl.) The very young, free-swimming larva of the coelenterates. It usually has a flattened oval or oblong form, and is entirely covered with cilia.

Webster 1913