The only local records of freshwater polyps in the country correspond to Cordilophora caspia (Pallas) (Cordero, 1941), in Las Brujas stream near the capital city of Montevideo and to a hydranth
of Calpasoma dactylopterum Fuhrmann 1939, casually mentioned by Dioni (1974) as occurring in an artificial pond in Montevideo without further detail.
Hydroid: stolonal, hydranth
1-6 mm high, with very short pedicel, perisarc smooth.
ovoid, with 20 to 32 thin tentacles, about 1.4 mm long.
(1978) proposed that increased chloride concentrations tend to produce larger colonies with more tentacles per hydranth
in habitats in Texas.
For all samples, we removed one haphazardly chosen hydranth
from a colony and placed it on a glass slide.
Since every part of the stem of Tubularia is capable of producing a hydranth
the inhibition of basal development is obviously due to the presence of a hydranth
or of a developing hydranth
at the oral end.
In these juvenile polyps, the cushion-like tissue disappeared into the endoderm of the aboral half, and many digestive gland cells developed in the endoderm of the oral half of the hydranth
Surface areas were determined from length and width (average of widths at top and bottom of cell), measured for rectangular hydranth
cells, and diameter for circular tentacle cells.
infrastructure and cytochem-istry of glycogen-containing vacuoles in gastrodermal cells in developing hydranths
of a hydromedusan coelenterate.
Lovenella gracilis is active only (as indicated by presence of hydranths
) from April to October in Virginia (Calder 1990).
The regression-replacement cycle of hydranths
of Obelia and Campanularia.
bear polyps (hydranths
) with which the animals catch their prey.