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.
Hydranth 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 (Fig.
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.