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(invertebrate zoology)
A larval, free-swimming medusoid stage of scyphozoans; arises from the scyphistoma by transverse fission. Also known as ephyrula.



the larva of most coelenterates of the class Scyphozoa. The larvae are formed asexually by means of transverse fission of the polyploid generation—the scyphistoma. The edge of the umbrella forms eight double lobes. Tentacles and oral lobes are absent. The digestive system is rudimentary: in addition to the stomach, there are only two rudiments of radial canals. The youngest ephyrae are transparent and reach several mm in diameter. Transformation into an adult jellyfish is accompanied by rapid growth. The edge of the umbrella becomes more regular, and a complex gastrovascular system, lateral tentacles, and the rudiments of sex glands develop.

References in periodicals archive ?
The localization of FMRFamide and tubulin immunoreactivity was best followed through a developmental sequence starting with the just-budded ephyra of Aurelia since the two stained subumbrellar networks showed very different relationships with the locomotory musculature in the early medusoid forms.
A tubulin-IR network was associated with the swim musculature of ephyra, staying within the limits of the circular muscle disc and the two radial muscle bands that run on either side of each ephyral arm.
Growth of ephyra included a disappearance of the arms and an extension of the circular muscle disc toward the manubrium.
Both FMRF-IR and tubulin-IR networks were found in the exumbrella of ephyra and medusae, although tubulin staining was less intense.
In the ephyra, exumbrellar nematocytes were mostly scattered rather than clumped (Fig.
Miscellaneous organisms consisted of Platyhelminthes, brachiopods, two cyclopoid copepods, nematodes, and a single ephyra of Aurelia spp.
To examine the kinematic profile of a swimming ephyra and its lappets, we used video (250 fps) of a 0.
High-speed (250 fps) video recordings of fluorescein dye transport around a swimming ephyra demonstrated boundary layer occlusion of the inter-lappet clefts.
As this fluid was shed, the ephyra moved forward, leaving behind it a series of dye-marked fluid "tracks" that resemble the outlines of the lappets (Fig.
Bioenergetics of ephyra larvae of the scyphozoan jellyfish Aurelia aurita in relation to temperature and salinity.
Ephyra size was positively related to food; diameters increased by 10.