Immortal Jellyfish

Image: Alvaro E. Migotto

Turritopsis nutricula is the Immortal Jellyfish. You might think that your gigantic brain makes you all great or whatever and maybe you can get it frozen after you're dead so that it can be uploaded into a robot in a million years but this here is the real deal.

It's in the class Hydrozoa, like Hydras and Blue Buttons (also Portuguese Man o' War, but I must have linked to that a million times by now) rather than Scyphozoa, which is where your classic jellyfish like the Lion's Mane and everyone's favourite Moon reside.

Image: Alvaro E. Migotto
Hydroid colony.

The lifecycle of the two groups are often quite similar. Male and female jellyfish release gametes, eggs become larval planulae that seek out a surface to rest on before becoming a polyp. But Hydrozoan polyps are called hydroids and they are usually colonial. They make up a little tree, with polyps all connected to each other by a tube. The Immortal Jellyfish uses a stolon that runs along the ground like strawberry runners. It's just that the stuff that grows up from them are polyps with stinging tentacles rather than juicy fruit. Ah, well.

The hydroid colony now releases tiny jellyfish, or medusoids, that are just a millimetre across. They feed on plankton and grow to a maximum size of about 4.5 millimetres (0.18 in) after 2 to 4 weeks. They are now sexually mature and can reproduce in the usual way, but something extraordinary happens if conditions become unfavourable.

You might remember that the Salp was a weird creature that would reproduce until there was no food left and then they'd all die. The Immortal Jellyfish is little more clever than that. An adult will actually revert back into a polyp, absorbing the tentacles and the jellyfish bell as it reattaches itself to the ground. It now extends those same stolons to make a whole new hydroid colony. Lab experiments showed that they will do this as a result of starvation, temperature change or drops in salinity. They can also do this at any stage of jellyfish development, from being a tiny thing 1 mm across to a not quite as tiny, sexually mature adult.

Image: Alvaro E. Migotto

It's quite remarkable because cells have to transform into completely different kinds of cells. And of course, if they can do this ad infinitum it would mean they are biologically immortal! All they have to do is avoid getting eaten. But then again, don't we all?

These jellyfish are found all over the tropical and temperate world, perhaps spread by boats using water ballast. Dr. Maria Pia Miglietta of the Smithsonian Tropical Marine Institute said "we are looking at a worldwide silent invasion". It is clear. This world is a Jellyfish World. Just like all those other ways that the world or humanity is going to end: It's not if... it's when.

California Horn Shark

Image: Chad King / SIMoN NOAA

While not initially impressive, this lovely little shark is a great example of the fascinating things you can find out when you really get down and study an animal.

Angel Shark

Image: Philippe Guillaume via Flickr

Sometimes it's good to be a land animal. Especially a reasonably sizeable one. Take the beach for example. We can go there and play in the sand, build our castles and frolic under the Sun in near total safety. Sure you might get sunburnt or find grains of sand in your hair for days to come, but you probably won't get eaten. I mean, imagine if you were just walking along the seaside and a massive patch of sand reared up, its rapacious mouth ablaze with hunger as it gobbled you up. That would be horrible!

Blanket Octopus

The air around here is growing increasingly chilly and I think a nice, warm blanket to hide under is called for. All sorts of animals have lovely fur you can make one out of, but you have to do all the work yourself. Unacceptable! There is a very strange answer to this problem, so long as you can tolerate your blanket being soaking wet. The Blanket Octopus has come to tuck you in. I hope she's brought some hot chocolate along, too.

Lighthouse of the Desert

Rising forth from the mud and stone of the sea floor, an edifice strikes out at the darkness. Appearing as nothing more than a community of snowflakes, standing strong against black waters and crushing pressure.

There is snow, but it's marine snow. Crumbs from the top table that fall from sunlit realms, dragged downward by the night. There are stars, but they are brittle stars. A squirming handful of arms, each with a thousand feet. There are flowers, too, but they are sea lilies. Feathers held high on long stalks, like carnivorous palm trees waving in the breeze.

This tower is a home. Sparkling, white walls permit entry to the tiny. One couple will stay and grow too big to escape. A wedding, but a shrimp wedding. A home, but a living one. A crystal prison and a fortress against the wet, desert wasteland.

I'm Venus Flower Basket and I approve this message.

Land Planarian

Image: Wikimedia

When I first saw the words "Land Planarian" I thought it was some kind of tiny, desktop greenhouse. I imagined tiny gardens and tiny jungles, tiny fruit on tiny trees and tiny leaves adrift on tiny rivers. I imagined a miniature wonderland of lush foliage right there on the living room table.

But then I saw one.