hydranth


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hydranth

the normal COELENTERATE polyp, having a mouth surrounded by tentacles, found in most colonial forms.
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Hydranth more or less ellipsoid, with 10-16 long tentacles, about 465 mm long.
Hydranth ovoid, whitish, with 14 tentacles, each about 400 [micron]m long.
Hydranth yellow or pale, spherical, with 25-28 tentacles, about 810 [micron]m long each.
For all samples, we removed one haphazardly chosen hydranth from a colony and placed it on a glass slide.
one block, block 1+2, block 1+2+3) were compared to determine the minimum number of nematocysts needed per hydranth to find a stable and accurate average for that type of nematocyst.
Within a population, if the means for each type of nematocyst are significantly different between the hydranths, the hydranths of a population constitute pseudoreplicates, and the 25 measurements per nematocyst type per hydranth can be averaged to provide a single mean.
A number of experiments have been made that seem to indicate that the temporary inhibition of the development of the basal hydranth in Tubularia is not the result either of the using up of materials by the oral hydranth, or of the setting free of inhibitory stuff.
A cut end being present, whether oral or basal--the conditions that call forth hydranth formation are given.
In other words, there is no speeding up of hydranth formation as such, but the initial inhibition is overcome.
Pyefinch and Downing, 1949; Berrill, 1952; Hawes, 1958; Lemire and Bourget, 1996), concluding that, because of their direct development, these larvae should be considered merely hydranths with rudimentary stalks, or only juvenile polyps.
Zooanthellate digestive cells of Myrionema ambionense have two general shapes: columnar from the hypostome (= cup) region of the hydranth (also called digestive cells here, Fig.
The mean density of zooxanthellae per hydranth cell was 2.