Planula

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planula

[′plan·yə·lə]
(invertebrate zoology)
The ciliated, free-swimming larva of coelenterates.

Planula

 

one of the larval stages in the development of coel-enterates. The body is oval, elongate, or wormlike; it consists of two layers. The outer layer, or ectoderm, consists of flagellate cells, among which are distributed musculoepithelial cells, nerve cells, and nemocysts. The inner layer, or endoderm, bounds the closed cavity of the gut. The planula swims in the water, subsequently attaching itself to the bottom and proceeding to the next stage of development—the polyp.

References in periodicals archive ?
If, as a result of volcanic action, a land mass emerges at suitable latitudes, a never-ending process of colonization by coral planulae and propagules of various other benthic organisms begins.
The anemone Actinia tenebrosa produces aggregated clones as a consequence of asexually produced planulae, 95% of which settle within 50 cm of the natal anemone (Ottaway 1979).
Embryos released from females (following internal fertilization) were photographed, and videos were taken to document developmental stages from blastulae to free-swimming planulae (following methods in Lewis et al.
Induction of metamorphosis by bacteria and ions in the planulae of Hydractinia echinata: An approach to the mode of action.
elegans, which possesses crawling planulae (Gerrodette 1981; Fadlallah 1983a), declined significantly with increasing distance of separation.
Energetic considerations in the dispersal of Pocillopora damicornis (Linnaeus) planulae.
Five-day post-fertilization Acropora millepora (Ehrenberg, 1834) planulae were kindly made available by Francois Seneca and Bette Willis at Orpheus Island Research Station, Great Barrier Reef (18[degrees]35'S 146[degrees]29'E)(CITES permit 2009-AU-563189).
Furthermore, the selective settlement responses of coral planulae (Wallace 1985) may enhance their survivorship relative to nonselective asexual recruitment of fragments.
Many bacterial phylotypes detected in planulae and post-settlement stages of P.
Multiple sensory cues, including chemicals and light, influence navigation and habitat selection in coral planulae (1-2).
capitata releases both sperm and eggs, packaged in egg bundles that disintegrate at the water surface to cross-fertilize with those of other colonies; the embryos develop into planulae within a couple ol days (Richmond.