A free-swimming coelenterate larva with a flattened, ciliated, solid body.
- ‘The planulae of most cnidarians attach and lose, at most, a coat of swimming cilia.’
- ‘The planula larva has very few apoptotic cells.’
- ‘Hydra lives in freshwater, lacks a ciliated planula, and has clearly lost a medusa stage during its ancestry.’
- ‘Fertilized eggs may be brooded for a time or may develop directly into a free-swimming, ciliated planula larva.’
- ‘The planula larva settles on a hermit crab shell and metamorphoses into a primary polyp.’
Late 19th century: modern Latin, diminutive of Latin planus plane, flat.
We take a look at several popular, though confusing, punctuation marks.