Search results
Results from the WOW.Com Content Network
Hydra (/ ˈ h aɪ d r ə / HY-drə) is a genus of small freshwater hydrozoans of the phylum Cnidaria.They are native to the temperate and tropical regions. [2] [3] The genus was named by Linnaeus in 1758 after the Hydra, which was the many-headed beast of myth defeated by Heracles, as when the animal has a part severed, it will regenerate much like the mythical hydra's heads.
All hydra cells continually divide. [15] It has been suggested that hydras do not undergo senescence, and, as such, are biologically immortal. In a four-year study, 3 cohorts of hydra did not show an increase in mortality with age. It is possible that these animals live much longer, considering that they reach maturity in 5 to 10 days. [16]
Hydra were observed for four years without any increase in mortality rate. [3] If the mortality rate remains constant, the rate determines the mean lifespan. The lifespan may be long or short, though the species technically does not "age". Individuals of other species have been observed to regress to a larval state and regrow into adults ...
Hydra viridissima is commonly called green hydra due to its coloration, which is due to the symbiotic green algae Chlorella vulgaris which live within its body. [3] These creatures are typically 10 mm long and have tentacles that are about half of their length. [ 4 ]
Hydra oligactis. This species can reproduce in three ways: sexual reproduction, budding, and indirectly through regeneration. [11] When hydra reproduce sexually, simple testes, ovaries, or both will develop on the bodies of an individual. Sperm released into the environment by the testes enters the egg within the ovary.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
This is not a wholly unusual thing to do, as some drug labels do get revised after approval. Goldstein explained that Zoetis is "working actively" with the F.D.A. on the revision process.
The Lernaean Hydra or Hydra of Lerna (Ancient Greek: Λερναῖα ὕδρα, romanized: Lernaîa Húdrā), more often known simply as the Hydra, is a serpentine lake monster in Greek mythology and Roman mythology. Its lair was the lake of Lerna in the Argolid, which was also the site of the myth of the Danaïdes.