colony (biology)


Class Anthozoa - Sea Anemones and Corals

Organisms in the class anthozoa belong to the phylum Cnidaria. Anthozoans are marine and only exist in the polyp stage (no medusa stage). Organisms can be solitary (sea anemones) or live in colonies (corals). Sea anemones have an oral disk (surrounds the mouth at the top), a column (the “stalk” of the sea anemone), and a pedal disk with acontia (helps with anchoring to a substrait) on the bottom. Corals are colonial anthozoans. They can be stony or soft.

The Bestiary: Tunicates

Most of the creatures I review tend to be molluscs, cnidarians or crabs. This is because my utter adoration with these phyla. But every once in a while I wipe the nerdy fanboy-froth from my mouth and turn my attention towards other groups.

And boy howdy is it worth it.

Tunicates (subphylum Tunicata) are some of the most bizarre shit the tree of life features, and considering the bizarre shit I’ve seen since I started running the blog, that’s saying something. For starters, Polycarpa aurata looks like a goddamn heart, and it only looks weird, it’s not on the level of batshit insanity some other tunicates are.

Just look at that lovely thing. Did I mention that it’s a closer relative of ours than insects?

Yup, it is. For looking like a prehistoric sponge’s retarded cousin, these guys are pretty innovative in some ways. Namely, they are some of the first Chordata, which means they have a notochord; pretty much the ancestral version to our spinal columns, except made of fluid-inflated cells staying in place because of the pressure they have towards one another. Basically a balloon animal spine.

Too bad they looked on their dazzling new notochord, said “fuck that” and decided to lose it and become primitive sessile or drifting Cnidarian/Poriferan knockoffs. Out of the three tunicate classes, two lose their notochords upon reaching adulthood, which is absolute bullshit. Change apparently scares them.

The first class, the Thaliacea contain the salps (Salpidae), who are reknowned for looking like jellyfish and having the most efficient jet propulsion in the entire animal kingdom with which they can fuck an octopus twice over. Also, they have a tendency to quite literally stick together side to side and traverse the oceans in colonies not unlike meters-long translucent toilet chains.

They look like one of those segmented snakelike bosses from shoot-em-up games where you have to destroy each segment separately.

See? I ain’t kidding.

The other significant members of the class are the order Pyrosoma, colonial organisms somewhat resembling siphonophores. They range from bioluminescent little trinkets,

to friggin enormous ravening worm monsters that are pretty much the final boss of the entire ocean.

Roll for initiative, bitch

Next up are the  Ascidiacea, a class of pretty chill sessile tunicates, except for the predatory tunicate (Megalodicopia hians), an animal that could be best described as Pac-Man if Toru Iwatani designed him on a particularly disturbing LSD-induced bad trip.

This thing waits around all day until something swims into its mouthlike hood, at which point it will close its mouth and digest it alive. It’s not exactly special, but considering it belongs to an entire subphylum of wimpy-ass filter feeders, it still is sort of a big deal. And holy hell does it look ghastly as all fuck.

The final class is Larvacea, the only ones who have the good sense to not throw out one of the greatest evolutionary achievements out the window when they hit adulthood. These folks keep their notochords and even most other larval features, which ironically puts them miles before their more radically changing cousins in terms of complexity. And also they slightly resemble Chestbursters.

Larvaceans are free-floaters who employ some of the most creative usage of slime that would put Portal 2 to shame if these guys ever heard of Portal 2 or had hands to play it.

This is how it goes.

Every day, they secrete shitloads of a special, sticky mucus they use to build a “house” around themselves. While this house would probably worth fuck-all in the face of a wolf trying to acquire three talking pigs, it does a mighty fine job filtering food for its inhabitant. The larvaceans’ “mucus house” is one of the most efficient filtration devices known to man, cycling seawater through several ludicrously complex filters that would cause any fluid physicist of your choice jizz their pants on the spot.

You can’t even see the larvacean in there, but I can assure you, it’s definitely inside. It’s like those evil overlords who never leave their thrones.

Overnight the filters get completely jammed with debris, forcing the larvacean to leave the house (through an emergency exit made explicitly for this purpose, no less) and create a new one from scratch.

Let me remind you that this thing is made entirely out of mucus and yet it still works. I don’t know if you ever tried to make seawater filters out of Jell-O but I can assure you that it’s damn hard. And yet this guy does it daily despite having the brain capacity of a flatworm. Have you done something productive today? No? What’s your excuse?

The Bestiary: Aggregating Anemone

When you hit up a blog dealing with various weird and badass sea creatures, I do believe anemones are not the first things you expect. I mean, really. What do anemones even do aside of waving their tentacles around all day like the lazy asses they are and providing background for done-to-death pastoral postcard images involving clownfish frolicking around in the limp embrace of Cnidarian tentacles? I feel dirty just from writing that down.

Frankly, anemones are boring as fuck.

Then again, anemones usually don’t do this.

The keyword being “usually”.

Today’s Episode: the Aggregating Anemone

If any of you missed my brilliant pun, I referenced “Clone Wars”.

Because that’s literally what this Jell-O fuck does, it wages clone wars. Really.

It goes by the name of aggregating anemone, or Anthopleura elegantissima. Even it’s name tells you it’s fucking fabulous, and you better keep that in mind or it will declare war on your ass and that’s something I wouldn’t wish upon anyone, not even my worst enemies.

It doesn’t just sit on its ass by itself, instead reproducing asexually at insane speeds (the process itself basically consists of the anemone tearing itself in half), completely covering unusually huge-ass boulders within unusually short amounts of time, turning itself into a legion of genetically-identical killer polyps flipping off the entire world with a translucent, slime-coated middle-finger.

And to top the menace factor off, they are the closest thing the shore fauna has to a xenophobic alien empire: they are perfectly identical genetically, and hate the guts of absolutely everything that’s genes and chemical markers are not a 100% match to theirs. Thus, they are known for attacking anything unlucky enough to accidentally cross the borders of Glorious Anemone Homeland, including other aggregating anemones. You know what this means.

Both anemone colonies will fortify their borders with special “warrior” polyps possessing big knobbly tentacles, all of which are positively crammed with special venomous weapon cells known as “nematocysts”. It’s a bit hard to explain how they work, but imagining them as a blend of a poison syringe and a harpoon gun is a pretty close approximation. Observe:

Meanwhile, the inner parts of the colony will employ their symbiotic algae to crank out as much energy for the unstoppable war machine as possible, occasionally going even further and swallowing entire crabs whole and only spitting back out their empty shells, completely scoured of flesh. Jesus Christ, anemones can be hella scary.

The warfare itself follows the tidal cycle. During low tide, the opposing legions lay low and gather energy, only to start the carnage again when high tide comes. When two warrior polyps stretch too close to each other, they will duke it out in an epic shower of venomous cellular death-harpoons, resulting in both of their deaths and the formation of a “demilitarized zone” or “no-man’s-land”, if you will.

Pictured: the closest thing to open armed conflict that can happen on fucking sea shores

Occasionally, a lone polyp will be accidentally left on the deserted territories, hopping around awkwardly to locate its comrades, these are subjected to a bionic volley of dart fire by the opposing faction, and either get killed to death or return to their own armies, heavily wounded, where in turn they get fucking murdered by their own brothers-in-arms, because of their altered chemical signals resulting from the enemy’s venom in their bodies. Fucking assholes never heard of comradery or heroism.

The deaths of these lost soldiers aren’t in vain, though, since that’s apparently how the colony approximates the borders of enemy territory, that is, by the frequency of wounded polyps returning home. The aggregating anemone is so hardcore that it determines the position of the enemy by executing its own failed warriors.

Fucking vikings had nothing on these little slimy shits, and they are only anemones.


CreatureCast:  Siphonophores and Individuality

In this episode of CreatureCast, Dr. Casey Dunn from Brown University talks about how siphonophores shake up the idea of individuality.

It’s easy to regard individuals as atomized and autonomous, but Siphonophores undermine our conceptions of individuality. Siphonophores are tiny jellyfish that are pieced together to produce what looks like a single, larger organism. This stunning emergent property reminds us that we, too, are both made up of parts and are part of something bigger.

Deep sea footage is courtesy of Dr. Steve Haddock at the Monterey Bay Aquarium Research Institute. Still are from papers by Haeckel, Bigelow and Vogt. Music by Lucky Dragons. Edited by Sophia Tintori.

(via: Dr. Casey Dunn)