Reproduction and Life Cycle
When food is plentiful, many Hydra reproduce asexually by producing buds in the body wall, which grow to be miniature adults and simply break away when they are mature. When conditions are harsh, often before winter or in poor feeding conditions, sexual reproduction occurs in some Hydra. Swellings in the body wall develop into either a simple ovary or testes. The testes release free-swimming gametes into the water, and these can fertilize the egg in the ovary of another individual. The fertilized eggs secrete a tough outer coating, and, as the adult dies, these resting eggs fall to the bottom of the lake or pond to await better conditions, whereupon they hatch into nymph Hydra. Some, like Hydra circumcincta and Hydra viridissima, are hermaphrodites and may produce both testes and an ovary at the same time.
Many members of the Hydrozoa go through a body change from a polyp to an adult form called a medusa. However, all Hydra, despite being hydrozoans, remain as polyps throughout their lives.
Read more about this topic: Hydra (genus)
Famous quotes containing the words reproduction, life and/or cycle:
“Although Samuel had a depraved imagination—perhaps even because of this—love, for him, was less a matter of the senses than of the intellect. It was, above all, admiration and appetite for beauty; he considered reproduction a flaw of love, and pregnancy a form of insanity. He wrote on one occasion: “Angels are hermaphrodite and sterile.””
—Charles Baudelaire (1821–1867)
“The truth is, I do indulge myself a little the more in pleasure, knowing that this is the proper age of my life to do it; and, out of my observation that most men that do thrive in the world do forget to take pleasure during the time that they are getting their estate, but reserve that till they have got one, and then it is too late for them to enjoy it.”
—Samuel Pepys (1633–1703)
“Oh, life is a glorious cycle of song,
A medley of extemporanea;
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And I am Marie of Roumania.”
—Dorothy Parker (1893–1967)