Know your jellyfish

[Staff]

Know your jellyfish:
some sting, some don't
by Dr J Floor Anthoni

Know your jellyfish
excerpt from above:

All cnidaria have stinging cells (cnidocytes), capable of inflicting rashes, stings or even burns. The animals can make these amazing cells at such rate that they can be used as dispensible tools. They can have different types, for stinging, sticking and gripping. The one shown in the diagram is of most concern to us since it is what causes the feared sting. The skin of a jellyfish tentacle is studded with these stinging cells. Each has a trigger hair (cnidocil) that activates a nerve circuit to unlatch the lid (operculum) and at the same time compress the cell. Several adjacent cells can be triggered simultaneously. Inside the capsule, the harpoon and its stinging thread (nematocyst) are ejected under pressure. The barbed harpoon is filled with poisons and everts itself like turning a finger of a rubber glove inside out, punching a hole in one's skin, releasing the poisons and pushing the thread into the punctured skin, to release even more poison. Once used, a stinging cell is discarded and replaced within two days. It is so amazing that such a complicated double-walled structure is made by a single cell!

[Equilibrium]

Forgive me.... I can't resist. It's a photo from my email that dropped my jaw to the desk.

[suunto]

Originally Posted by Equilibrium

Forgive me.... I can't resist. It's a photo from my email that dropped my jaw to the desk.

This appears to be a composite image. The largest known jellyfish has a maximum bell diameter of a little more than seven feet - see Lion's mane jellyfish - Wikipedia, the free encyclopedia

[Equilibrium]

It's a hoax!!! Bummer. I thought I had a really special new invasive species from an e-mail. The fake photo is impressive. I take it somebody photo shopped it somehow?

[TheLorax]

My dear Lib, I believe you were had.
Giant Jellyfish
Giant Jellyfish Optical Illusion | Mighty Optical Illusions
Giant Jellyfish on Flickr - Photo Sharing!

[Equilibrium]

It's not the first time.... it won't be the last.

[jpdenk]

Originally Posted by Equilibrium

It's a hoax!!! Bummer. I thought I had a really special new invasive species from an e-mail. The fake photo is impressive. I take it somebody photo shopped it somehow?

Yep, actually a fairly easy one to Photoshop.

[Staff]

Giant deep sea jellyfish filmed in Gulf of Mexico
By Jody Bourton
Earth News reporter
Page last updated at 11:35 GMT, Friday, 23 April 2010 12:35 UK

BBC - Earth News - Giant deep sea jellyfish filmed in Gulf of Mexico
excerpt from above:

Remarkable footage of a rarely seen giant deep sea jellyfish has been recorded by scientists.

Using a remotely operated vehicle (ROV), they captured a video of the huge Stygiomedusa gigantea...