Definify.com

Webster 1913 Edition


Planula


Plan′u-la

,
Noun.
;
pl.
Planulæ
(#)
.
[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
.
2.
(Zool.)
The very young, free-swimming larva of the cœlenterates. It usually has a flattened oval or oblong form, and is entirely covered with cilia.

Definition 2024


planula

planula

English

Noun

planula (plural planulae)

  1. (biology) 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.
  2. (zoology) The larva of a hydrozoan, which is free-swimming and covered in cilia.

Derived terms

  • planular
  • planulate