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The Jellyfish that Conquered the Earth
September 1, 2011 4:39 PM   Subscribe

Myxozoa are microscopic parasites that infect fish, amphibians, and now, birds and at least one terrestrial mammal. For over a hundred years they were classified at protozoa. More recent research reveals that classification to be wide of the mark: They’re jellyfish.

Jellyfish week on Metafilter continues:

Myxozoa have a complex life cycle that involves infecting two different hosts at different times, an aquatic invertebrate (usually a worm) and a vertebrate (usually a fish).

In the early 1990s, it was confirmed that, tiny as they are, myxozoa are multicellular. So they’re not protists after all. Furthermore, they have special harpoon cells that look like the nematocysts, or stinging cells of cnidarians — the group that includes jellyfish, sea anemones, and corals.

Early on, the animal kingdom diverged into those with radial symmetry which includes the cnidarians; and those with bilateral symmetry, which includes all the mammals, birds, reptiles, amphibians, fish, arthropods -- and worms.

Enter Buddenbrockia plumatellae, a myxozoa that appears as an active, muscular, parasitic worm inside its host, the bryozoan, or moss-animal (which are pretty weird themselves).

Buddenbrockia has rarely been seen since its discovery in 1851, and as a ‘worm’ has always been classified as a bilaterian (at least). But in 2002, genetic analysis placed it with the myxozoa.

Then in 2007, further study revealed:
  • The Buddenbrockia worm is not bilaterally symmetrical: 'It has no mouth, no gut, no brain and no nerve cord. It doesn't have a left or right side or a top or bottom. We can't even tell which is end is the front!' -- Peter Holland (Oxford University) It has two axes of symmetry and four longitudinal bands of muscle, so it's actually a tetra-radial worm.
  • They have cnida (stingers) like all cnidaria.
  • Further genetic analysis indicates they’re related to medusozoans — the jellyfish.
This means that the worm-like body shape evolved at least twice from two completely different kinds of animal. “It is one of the most striking examples of convergent evolution you will ever see. . . convergent evolution [not] of individual organs or body parts, such as eyes or wings, but of the whole body shape.”-- Peter Holland

Why we should care
Myxozoa are parasitic animals that live in marine and freshwater aquatic habitats. They are found in virtually all fish. Currently the most economically damaging species Myxobolus cerebralis is the cause of the “whirling disease” in salmon and trout, with up to 90 percent mortality in farm-reared fish.

Mxyozoa are responsible for the decline of native endemic Australian frogs. The introduced Cane Toads did not seem to have brought the parasite with them, but do act as a “spillback” carrier.

Mxyozoa were previously believed to infect only invertebrates and cold-blooded vertebrates. However, researchers at Oregon State University have discovered a new species that infects birds (ducks).

In the Czech Republic, a myxozoa parasite has been confirmed for the first time in mammals (the common shrew).
“It’s pretty clear it has now moved into warm-blooded animals, which some other research has suggested may include moles, shrews and even humans with compromised immune systems.

“The Cnidaria have undergone a niche expansion that allows the exploitation of warm-blooded terrestrial vertebrates by essentially aquatic animals”. -- Jerri Bartholomew (Oregon State University)
So there you have it
  • Long ago, an ancestor of the jellyfish took an evolutionary detour into a parasitic lifestyle.
  • A radially-symmetrical cnidarian somehow evolved into a wriggling elongated worm.
  • Jellyfish are invading dry land as microscopic parasites in frogs, ducks, shrews and. . . ???
posted by Herodios (34 comments total) 72 users marked this as a favorite

 
i am not ready for this jelly
posted by The Whelk at 4:44 PM on September 1, 2011 [33 favorites]


Thanks ducks and shrews! You damned warm-blooded quislings! You've opened the gates for our jellyfish innerlords....
posted by GenjiandProust at 4:50 PM on September 1, 2011 [2 favorites]


If you guys need me, I'll be cowering underneath my desk in the fetal position.
posted by strangely stunted trees at 4:58 PM on September 1, 2011 [9 favorites]


posted by lekvar at 4:58 PM on September 1, 2011 [5 favorites]


Trypophobia trigger alert: don't do an image search for bryozoans.
posted by Threeway Handshake at 5:09 PM on September 1, 2011 [1 favorite]


Calling Carl Zimmer to the white courtesy phone. Carl Zimmer to the white courtesy phone.
posted by onhazier at 5:16 PM on September 1, 2011 [1 favorite]


What we need to do is introduce a parasite that kills myxozoa, see, and then . . .
posted by IvoShandor at 5:17 PM on September 1, 2011 [2 favorites]


Great. Now I have to switch back to peanut butter and leech sandwiches.
posted by benzenedream at 5:18 PM on September 1, 2011 [1 favorite]


And I, for one, categorically do not welcome our new microscopic parasitic jellyfish overlords.
posted by UbuRoivas at 5:24 PM on September 1, 2011 [5 favorites]


Cool! Yesterday it was brain-eating amoebas, and today parasitic jellyfish. I'm beginning to think delusional parasitosis is only the sane response.
posted by sneebler at 5:41 PM on September 1, 2011 [1 favorite]


It hardly seems delusional anymore.
posted by clockzero at 5:47 PM on September 1, 2011


can someone just smack the pen out of Peter Watts' hand so he can't will anymore things into being?
posted by The Whelk at 5:49 PM on September 1, 2011 [10 favorites]


Actually, onhazier, as I was reading the article I thought "Man this is good, detailed writing. I'll bet it's Carl Zimmer."
posted by benito.strauss at 5:55 PM on September 1, 2011


UbuRoivas: "And I, for one, categorically do not welcome our new microscopic parasitic jellyfish overlords"

You jelly?
posted by Rhaomi at 6:21 PM on September 1, 2011 [1 favorite]


Spineless.
posted by UbuRoivas at 6:43 PM on September 1, 2011


so cool.
posted by eustatic at 6:48 PM on September 1, 2011


Enjoy the gritty crunch. They taste just like chicken!
posted by markkraft at 7:07 PM on September 1, 2011


Aren't we supposed to call them jellies now, instead of jellyfish?
posted by KGMoney at 7:26 PM on September 1, 2011


No, because then there would be no jellyfishing, and that would make Spongebob Moss-Animal-Pants sad.
posted by Slap*Happy at 7:38 PM on September 1, 2011 [1 favorite]


And they live inside moss animals? Are you kidding me? What planet is this?
posted by swift at 7:38 PM on September 1, 2011 [3 favorites]


if they're inside me, how am I supposed to pee on them?!?!??!!!
posted by Bohemia Mountain at 7:44 PM on September 1, 2011 [5 favorites]


Any animal with a life cycle involving other species is bad news. Fascinating news, but bad.
posted by Countess Elena at 7:49 PM on September 1, 2011 [1 favorite]


Cnidarians are the bomb-diggitty. Who needs a brain, or jointed appendages? Nobody.

For the last few years I have wanted to be professional basketball player. But in order to really make a go of that, I need my top half grafted onto the bell of a flying, air-breathing jellyfish, 8 or 10 feet in diameter, with tentacles in proportion. My kids are going to make this happen for me; that's why they have to go to college.
posted by pH Indicating Socks at 9:05 PM on September 1, 2011 [1 favorite]


Trypophobia trigger alert: don't do an image search for bryozoans.

Trypophobia trigger alert: don't search for trypophobia unless you immediately want to find out if you have it.
posted by schmod at 9:43 PM on September 1, 2011 [3 favorites]


Hey, fuck our new cnidarian overlords.
posted by Mister_A at 5:29 AM on September 2, 2011


(Awesome post but I hate jellyfish)
posted by Mister_A at 5:30 AM on September 2, 2011


Fabulous post, but oh god oh god oh god oh god oh god ....
posted by Theta States at 7:00 AM on September 2, 2011


So Lovecraft was right and every incremental advance in knowledge does lead to horror.
posted by Peztopiary at 7:10 AM on September 2, 2011 [1 favorite]


You know, benito.strauss, I had a similar thought. Herodios wrote a great post and it felt like something which would pass Carl Zimmer's rules for science writing.
posted by onhazier at 8:04 AM on September 2, 2011 [1 favorite]


Aren't we supposed to call them jellies now, instead of jellyfish?

"Jellies" is a descriptive term which includes several groups of animals of widely divergent ancestry -- jellyfish (Cnidaria), comb jellies (Ctenophora), and even tunicates (Chordata).
posted by endless_forms at 8:05 AM on September 2, 2011


if they're inside me, how am I supposed to pee on them?!?!??!!!
posted by Bohemia Mountain at 7:44 PM on September 1 [4 favorites +] [!]


I got some websites you should check out. They're... educational.
posted by FatherDagon at 8:29 AM on September 2, 2011


Speaking of "living things that are shaped different", the first few episodes of "The Shape of Life" talked about some of the more exotic body plans that nature tried.
posted by benito.strauss at 9:09 AM on September 2, 2011 [1 favorite]


So this (excellent) post led me into some idle rabbit-trailing through wikipedia on the subject of jellies, and therein I discovered that keeping jellies as desktop pets is apparently a thing.
posted by jquinby at 6:54 PM on September 2, 2011


keeping jellies as desktop pets is apparently a thing.

"More research is needed."
 
posted by Herodios at 8:08 PM on September 2, 2011


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