Jo Canadian is right to point out that the loose term "jellyfish" covers several classes of animal that look the same superficially, but that are actually as different from each other as gerbils are from humans, so trying to generialize about "jellyfish" is stupid. Silly me.
I believe you have to have a receptor (brain) in order to have nerves. Jelly fish don't. Science says they've proven that Lobsters and crabs have no pain receptors.
However. The thought of maliciously doing something to any living creature is cruel. Especially if the only purpose served is for amusement
The "phylum" (humans belong to the "vertebrates" at this level of classification) that jellyfisn belong to comprises the the first type of creatures to possess a recognizable nervous sytem, a loosely arranged "neural net" they have sensory nerve cells as well as true muscle cells and cells that make the muscle cells work.
Jellyfish (or at least most of them) can tell food fron non-food and won't pull non-food into their mouths. they can sense light and some species even use the sun to migrate, so it's pretty clear to me that they sense their environment.
Even single-celled creatures like algae, amebas and even bacteria swim towards thing they "like" and away from noxious stuff.
Lobsters and crabs definitely have nerve cells that tell them when ther're being damaged, the argument is over whether or not they "feel" pain.
I agree with the Scandinavians that they probably don't, but "Until you've walked in another's shell..."
I definitely agree with the last part, though. The
gratuitous taking of any life always seem like a bit of a tragedy to me.
