Video of Hydra!

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

Video of Budding Animation

  • 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

17 Responses to Hydra

  1. BOC Sciences says:

    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.

  2. Taylor says:

    But what is it’s purpose?

    • Jung Choi says:

      From an evolutionary viewpoint, the purpose of any living organism is to reproduce and pass on its genes.

      • Taylor says:

        But there are certain microorganism’s that have a specific purpose this one just seems like one that exists with no purpose

        • Jung Choi says:

          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.

  3. Kendra says:

    Would a hydra be considered a hermaphrodite?

  4. karim khan says:

    Thanks. It was great help in my paper.

  5. godspower says:

    thanks for the your science discovery i think is wonderful

  6. Pingback: The Hydra: Near-Microscopic Octopus of the Fresh Water World

  7. Kirsten says:

    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.

  8. Jung Choi says:

    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.


    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

  9. bplee says:

    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

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