As soon as I saw 
The sea crashing against indomitable rocks conjured epics, and timelessness. Eventually I arrived at the legend of Hercules slaying the Hydra. Here's the story, if you want to refresh your memory. The important part about the legend for my blog is that the many-headed Hydra was believed to be immortal. Every time Hercules cut off one of its heads two grew back. Eventually Hercules found a way to trick the beast and kill it.
Hercules Slaying the Hydra
Image credit: John Singer Sargent. Museum of Fine Arts, Boston online database. Public domain.
I didn't think a familiar Greek legend was novel enough to write about so I looked for something more surprising. That I found when I learned about another immortal hydra, one that exists, in fact, today. This hydra not only can grow new heads. It can grow any spare part it needs, including a new version of itself. This multi-headed, self-replacing hydra has been described as biologically immortal.
Now, feast your eyes on the freshwater organism that may be more than 1000 years old. Behold a Methuselah of pond and stream life:
Hydra magnipapillata
Friederike Anton-Erxleben, Kiel University, Germany. Used under CC 2.5 license
The regenerative powers of Hydra magnipapillata were discovered more than 200 years ago. According to the website GeoChemBio.com, Hydra magnipapillata is a small freshwater polyp. It has a simple structure and is a member of the phylum Cnidaria. Cnidarians were the first animals to develop nervous systems.
The hydra stings with tentacles and injects toxins into its prey.
Here is a hydra catching a baby shrimp (Youtube)
Key to hydra's longevity is its ability to regenerate. According to one article published by the UC Davis Biology Department, if you cut off the head of a hydra, it'll grow a new one. If you chop up the organism, you just get a bunch of new hydras. And, if you put the organism in a blender, you get "a soup of hydra cells".
The hydra can actually exist if it loses its nervous system. It simple repurposes other cells to carry out the function of nerve cells.
Hydra Viridissima
Peter Schuchert. Used under CC 4.0
Hydra viridissima lives in temperate zones and is carnivorous (as are all hydra). It feeds on crustaceans, insects and annelids (information from Wikipedia). Hydra viridissima is called Green Hydra because of the algae that live symbiotically in its body.
Hydras are sessil and attach themselves to plants, or other stationary objects. However, a hydra can bend and stretch, and also if need be can detach itself and move to another place.
What Price Sex?
Interestingly, there is one species of hydra that reproduces asexually under some circumstances and sexually under other circumstances. Hydra oligactis can be induced to reproduce sexually if the water is cold enough. In its asexual phase, its cells do not show senescence. In its sexual phase, its cells do show senescence and have a life span of about one year.
Hydra Oligactis
Attribution: Lifetrance at en.wikipedia. Used under a CC 3.0.
The so-called biological immortality of hydra is more than just a matter of curiosity. Researchers are hoping to better understand the aging process by understanding how and why hydra cells avoid senescence. The key may be in stem cells.
According to one article, it is the need to maintain and produce germ cells (stem cells) that robs the organism of its ability to support other somatic cells. In lay terms, the hydra oligactis organism is apparently exhausted by sex :))
Other hydra species, for example the Hydra vulgaris pictured below, cannot be induced to reproduce sexually.
Hydra Vulgaris
Attribution: Corvana Used under CC 3.0 license
Hydra vulgaris (and all hydra, ordinarily) reproduces by budding. Here is an abbreviated description of budding by microscopemaster.com.
the new individual starts growing as a small body on one side of the parent...Ultimately, the new individual, which resembles the parent, detaches and becomes an independent organism.
This Youtube video shows a hydra reproducing asexually by budding:
It is believed that hydra have been on earth for 600 million years. It is also believed that Hercules may have been a historical figure who lived in the 13th century, B.C. While it would be a stretch (really big stretch) to imagine that the freshwater organism had anything to do with the Hercules legend, still... often in legend and tradition it is possible to find at least a grain of truth. In this instance, at least, there is a kind of analogue.
My Collage
I always knew there would be a monster. The first version began with a dog face.
Teeth creozavr on pixabay
Dog snout bya-mblomma
Tongue free vector Pixabay
But that didn't work out.
I kept the tentacles, which were all made from one starfish, and just kept copying and rotating the image: starfish hockladen on Pixabay
Eventually I found a statue of Hercules slaying the hydra (JDJ on Pixabay)
I got rid of the base and found a boulder on Pixabay by jazella
Played around with the color, started to make frames for a GIF so the hydra tentacles would move, and then ran those frames through GIMP.
Hydra accent pictures that dot the blog are public domain illustrations by Rodrigo. H. Costilhos
The hydra beast is also public domain by SylviaP_design on Wikimdedia Commons.
Every week I thank
Hats off to our teacher, 
Thank you for reading my blog