Branching Sponge Worm

Alright. We've seen some weird worms in our time but this definitely takes the biscuit. In fact it takes several hundred biscuits and arranges them so they spell out "Hey! Look at me! I'm mad, I am!"

It's Ramisyllis multicaudata, a polychaete worm from shallow waters off the coast of northern Australia. They live inside sponges, occupying the channels and tunnels through which water flows as the sponge filters out bacteria to feast on.

But there's a twist. Quite a few twists, in fact. R. multicaudata lives up to its name, and since "multicaudata" means "many tails", that's exactly what it has.

Their body branches out, and then the branches branch, and then they branch too, but not before a little more branching. Eventually, they may end up with several hundred tails! Sometimes they can even be seen poking out of the sides of the sponge, which is quite ghastly actually.

All the while their head is buried deep in the centre of their living fortress. The body is like some freakish network of roots and extremely fragile and easily broken, since they don't get out much at all. It's like those poor sods who got far too overweight and have taken on the shape of their favourite chair, and getting them out of the house has become a significant engineering challenge.

It's not necessarily certain what they eat. They may chew on bits of their sponge, just as we would take a nibble out of a gingerbread house, but it seems unlikely that one mouth could support all those tails. More likely is that they absorb the sponge's food as it passes by, much like a tapeworm.

I for one am stunned! In a world gone mad you could always rely on a worm being kinda long and kinda thin. Alas, even they have succumbed to the trend of having bits sticking out. I would never have thought it possible.