Hydromedusa


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The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Hydromedusa

 

(1) A genus of the Rhynchocephalia family of snake-necked tortoises. It is characterized by a very long neck (which exceeds the length of the dorsal shell) and by the presence of four claws on each of the front legs. The length of the carapace does not exceed 30 cm. There are two species, both freshwater and native to South America. Hy-dromedusa lays its eggs on the shores of inland bodies of water.

(2) Medusoid individuals of certain coelenterates of class Hydrozoa.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
However, those previous studies were made in the field, making it impossible to note more detailed behaviors, like those of Molina (1990) for other species of Brazilian Chelidae, (e.g., Phrynops geofroanus and Hydromedusa tectifera) observed in captivity.
Our study addresses this issue by examining the fluid interactions in Craspedacusta sowerbyi Lankester 1880, a freshwater, upstream-foraging, rowing hydromedusa (Hydrozoa: Olindiidae).
In this paper we present the finding of another invasive hydromedusa, Gonionemus vertens Agassiz, 1862 (Hydrozoa, Limnomedusae), found for the first time in the southern hemisphere.
The lire cycle of the commensal hydromedusa Eutima sapinhoa n.sp.
Description of a new hydromedusa from the southwestern Atlantic Ocean, Bougainvillia pagesi sp.
The invasive hydromedusa Blackfordia virginica (Cnidaria: Black-fordiidae) in southern Brazil, with comments on taxonomy and distribution of the genus Blackfordia.
A second strategy, observed among scyphomedusae and the small hydromedusa Obelia spp., is to swim using drag-based paddling (Feitl et al., 2009).
These new methods and technologies have allowed scientists to resolve the life cycles of many organisms whose hydroid and hydromedusa stages were previously thought to be separate species, and to conduct a variety of experimental studies in the laboratory.
The most transparent tissues (at 480 nm) were hydromedusa mesoglea (66%), followed by Cystosoma (42%), ctenophore mesoglea (41%), siphonophore mesoglea (39%), pelagic tunicares (excluding Pyrosoma) (33%), Sagitta (24%), and the translucent portions of the hydromedusae and ctenophores (24%).