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Related to Planula: scyphistoma, Colloblast


(invertebrate zoology)
The ciliated, free-swimming larva of coelenterates.



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 ?
Dada la cercana presencia del rio Almendares, en eventos de fuertes lluvias pueden producirse pulsos agudos de baja salinidad en Malecon y en menor grado en La Puntilla, cuyo efecto sobre los reclutas no pueden evaluarse en el presente trabajo y que en cierta medida pudieran afectarlos, atendiendo a los criterios de Jokiel (1985) y Richmond (1997) sobre la sensibilidad de los gametos y las planulas a ese factor.
At the beginning of the Planula Zone (Kimmeridgian), Ophthalmidium, Spirillina and Reophax diminish, whereas Ammobaculites and Lenticulina increase, although the values are recovered in the omission surface at the top of the section.
The fertilized egg develops into a planula that is released into the water when mature.
These organisms are important because they are common on the wall and are also interesting because much work has been done with Spirorbis setigers (Knight-Jones 1951), bryozoan cyphonautes larvae (Keough 1984), and crawling Alcyonium planula larvae (Sebens 1983).
These light-responsive microvillar cells have a motor cilium, so once again the planula can orient its movement relative to a fight source, though in this case the effect is directly on the ciliary beating pattern--no eyes, nerves, or muscles are involved.
and the planula larvae of the scleractinian coral Fungia scutaria.
In eight other coral species that have been examined (Apprill et al, 2009; Sharp et al, 2010), corals do not appear to inherit bacteria from parents; rather, bacterial colonization occurs in planula larvae or post-settlement stages.
Light influences the swimming behavior and settlement of the planktonic planula larvae of coral, but little is known regarding the photosensory biology of coral at this or any lift-history stage.
damicornis release planula larvae throughout the year according to specific lunar phases (Richmond and Jokiel, 1984; Jokiel, 1985), while M.
Effects of pressure on swimming behavior in planula larvae of the coral Pontes astreoides (Cnidaria, Scleractinia).
Frequent recent blooms are causing concern about the possible settlement of planula larvae and establishment of new populations in Japanese coastal waters (Uye, 2008; Ikeda et ai.
Feeding behavior and acquisition of zooxanthellae by planula larvae of the sea anemone Anthopleura elegantissima.