Thursday, June 13, 2013

Fun Facts About Jellyfish

For some reason certain classes of sea beasties are much more lovable and aesthetically pleasing than others, even if they aren't very useful or friendly and lack traditionally cute features like faces and easily-defined central nervous systems.

The giant Nomura's jellyfish, common (a little too common) off
the coasts of Japan, China and Korea. It may be the world's 
largest jelly, growing to over 300 pounds.
Source: Captain Custo




I know I'm not the only person with an inexplicable soft (and squishy) spot for cephalopods, crustaceans and many members of the slightly more bizarre phylum cnidaria, which includes not only jellies but also corals and anemones. 

These pretty, brightly-coloured stinging things have given many human pause over what, exactly, the difference is between a plant, and something that looks like a plant for part or all of its life but recoils more quickly when poked.


Well, even if venomous seafaring blobs aren't your cup of tea, they're pretty interesting and deserve at least a moment of consideration.

Jellyfish have been around for over 700,000,000 years, and are definitively proven to have been around for at least 500,000,000. That makes them the oldest multi-organ animal on Earth, three times the age of the first dinosaurs.

Box jellies have eyes like ours and are capable of learning. Actually, they have two eyes like ours and 22 others, but the pair in question is thought to be able to process images (as opposed to other jellyfish eyes that only process changes in light), via four parallel brains that comprise the most complex and unique nervous system of all the jellies. The combined powers of all two dozen eyes - which are situated on all sides of the jelly - may even give it a 360-degree view of the world. 


Image: National Geographic
Article: Science News For Kids
Even much simpler jellies aren't blindly drifting sea snot; they have demonstrated at least the basic ability to react to salinity levels and consciously change direction and speed.

Though box jellies are notorious for their stings, their nematocyst harpoons are so small that a pair of pantyhose should provide adequate protection from them.

Because most people aren't uncomfortable, unattractive and/or self-conscious enough in their swimsuits already.

One species of jelly, turitopsis nutricula, can revert to youth at will and may effectively be immortal. 

It sounds like something out of an anime or Sci Fi Channel movie, but this jelly can really re-absorb its tentacles and umbrella bell by altering the state of its cells and transforming them into new ones. It can then revert back to its polyp stage, even after having reached sexual maturity. Jellies traditionally hatch from eggs as itty bitty larvae, settle onto the sea floor or other surfaces and grow into colonies of polyps (kind of like corals) that bud off still-itty bitty planktonic jellies that float around and eat for a few weeks before growing to their adult size. These jellies live for mere hours, weeks, months, or a few years max. 

Even though turritopsis can do the impossible, its transformations have never been witnessed in the wild and the many hazards of being a one-millimeter floating snack after it's re-budded from a polyp probably render its death-cheating ability null, but it's still pretty damn cool, right?

Freshwater jellies have been found in at least 44 U.S. states and almost everywhere else, from Argentina to Thailand. 

Jellies are clear biological indicators of temperature shifts, and the fact that they were recently spotted in Canada and Russia is fairly alarming, as is the better-known ocean proliferation of these weird animals: jellies thrive in warm, oxygen-poor waters and in chemical and nutrient-rich agricultural runoff spots. 

But hey, thinking about a post-apocalyptic Waterworld-type scenario in which shallow polluted seas teeming with jellies wash over the areas where Florida and New York used to be isn't fun. What is fun is that the cute little freshwater suckers are the size of the band pins on your denim jacket and have about 400 little tentacles. D'aww. 

Japanese high school students started dealing with Nomura overpopulation by making the jellies into caramel candy. 

Leave it to the enterprising and resourceful Japanese to turn horrible fishing net bycatch into something sweet. If it comes from the ocean, they eat it. And if they don't, they'll figure out a way to process and eat it eventually. 

So, there you have it. Watching jellies is hypnotic, painting them is fun, and thinking about how they function is fairly mind-boggling. Even if your heart is filled with seething hatred for jellies because you've been unjustifiably attacked by one or several in the past, take solace in the fact that you can get your revenge by going to Japan and eating them as caramels. Or as an appetizer, if you prefer spicy to sweet. 

If you dig jellies, I reommend this article:
Much More to Jellyfish Than Plasma and Poison - NYT

and this really cool, bizarre Japanese movie:
Bright Future - IMDb

(Originally published 3.14.12)