Hydra is the name of a many-headed water beast in Greek Mythology…but it’s a real animal too!
- Hydra is a cnidarian
- It is exclusively a freshwater organism
- There are many different species of Hydra
- It is relatively small, being only a half a centimeter long on average
- Hydra have a tubular body, a “head” at the distal end, and a “foot” at the proximal end
- They use this foot for sticking to either rocks or the undersides of plants
- They have a ring of tentacles for catching food around the head
- Hydra only has ectoderm and endoderm (no mesoderm!)
Reproduction and Life Cycle:
- Hydras generally reproduce asexually
- They do this through budding
Asexual Reproduction in Hydra: 1: a bud begins to form on the tubular body of an adult Hydra. 2: The bud develops a mouth and tentacles. 3: The bud detaches from its parent. 4: The new Hydra is fully developed and will find its own location for attachment
- If the environmental conditions get bad enough, they are likely to switch to sexual reproduction, which increases the genetic variation in the population.
Why Study Hydra?
- Regeneration – Hydra can regrow a lost head or foot, or both!
- Senescence – Hydra do not show any signs of senescence (the process of aging) as long as they reproduce asexually. Studying Hydra‘s “immortality” may help in research on geriatric medicine. Interested in how Hydra could help with Alzheimer’s disease and Huntington’s disease? Read about it here.
- Stem cells – Hydras present a simple, non-controversial method for stem cell research. Common signaling pathways are responsible for stem cell functions in Hydra and humans. Read more about Hydra stem cells in this article by Thomas Bosch.
- Read here about advancements in discovering the pathways involved in Wnt3, “the master ligand”, signaling. HyWnt3 expression begins the cascade for Hydra head regeneration, controlled by two cis regulatory elements: HyWnt3act and HyWnt3rep.
Read more about Hydra from Encyclopedia Britannica
The first thought came into my mind is that it may be applied to anti-aging. With furtherly reading the my idea is mentioned. Hope the researches on this species can make some great finding.
But what is it’s purpose?
From an evolutionary viewpoint, the purpose of any living organism is to reproduce and pass on its genes.
But there are certain microorganism’s that have a specific purpose this one just seems like one that exists with no purpose
In science, “purpose” is a vague term. If you mean ecological niche, it definitely has its own ecological niche. It eats smaller freshwater organisms as well as detritus.
Would a hydra be considered a hermaphrodite?
Thanks for a lot of information!
Thanks. It was great help in my paper.
thanks for the your science discovery i think is wonderful
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Thanks for the information and video. I saw one of these at work today ( Melbourne, Australia) and wanted to find out some more about it. All the best with your studies.
Here’s a blog entry by Ed Yong on a new Science article on regeneration in Planaria – a roundworm. Unrelated to Hydra, but another model organism for regeneration.
http://blogs.discovermagazine.com/notrocketscience/2011/05/12/an-entire-flatworm-regenerated-from-a-single-adult-cell/
Reference: Wagner, Wang & Reddien. 2011. Clonogenic Neoblasts Are Pluripotent Adult Stem Cells That Underlie Planarian Regeneration. Science http://dx.doi.org/10.1126/science.1203983
And yet another Science paper on planarian regeneration:
http://www.sciencemag.org/content/332/6031/852.full
This paper is about Wnt signaling and a protein called notum: “Polarized notum Activation at Wounds Inhibits Wnt Function to Promote Planarian Head Regeneration.”
do hydra produce egg,if not why do they have ovary
Yes, they do produce eggs or sperm when they are triggered to undergo sexual reproduction. See this article: http://alinaklineschoder.wordpress.com/2011/11/15/reproduction-and-inheritance-of-the-hydra/
really they r sexual????
Authors by Page
Hydra: Main Page by J. Wright
Hydra: Genome by B. Lee
Hydra: Lack of Senescence by B. Lee
Hydra: Regeneration by J. Wright
Hydra: Why Should Hydra be a Model Organism by Byron Lee