Friday 2 September 2016

Munnopsis


Ah, the deep sea... It gives you wings!

Or at least a parachute made of legs. Hey, it's the thought that counts...

Image: MBARI
Munnopsis abyssalis
It might look like a pot-bellied alien weighing down a ramshackle spider web composed of its own legs, but that's because it's upside down. It's actually more pot-headed. Also, Munnopsis is a genus of isopods. That means they're related to woodlice, also known rather more sweetly as pillbugs and sowbugs.

Strange how very different one's relatives can be.

While woodlice scrabble around in the dark corners of the earth on their numerous little legs and roll up into a ball at the first sign of trouble, Munnopsis swims around in the darkest corner of them all, the deep sea, where they use up a lot more space than their 1 or 2 cm (0.5-1 in) body would suggest.

Image: University of Bergen
Munnopsis typica
They do like to spend time on the sea floor. That's where their food is, after all. They eat the same thing that a vast number of bottom-dwelling deep sea denizens eat, and that's 'anything'. There's a whole lot of 'anything' on the deep sea floor. It's where 'everything' ends up if it can make it, so there's fields of the stuff for a plucky detritivore.

If a Munnopsis isopod has eyes at all, they're reduced, and while they certainly have an exoskeleton, it's quite thin and weak. So they're glad to lift off from the sea floor, swim about with their little swimming legs and then just relax as their extensive parachute legs allow them to drift peacefully and effortlessly in the grand expanse of the deep. Chances are pretty good they won't bump into anything with teeth and if they do, they can manage a turn of speed to make their escape.

A good escape plan is especially important for females when they're carrying around a precious cargo of developing eggs. It's possible she doesn't even eat at this time, which might mean she needn't touch the seafloor at all. It seems to work out well for them. You can sometimes find hundreds of Munnopsis hanging out together and one species, M. abyssalis, can be found at depths from 1,000 m (3,280 ft) all the way down to 4,000 m (13,000 ft). They've also been found more than 2,000 m (6,500 ft) above the sea floor. That's a long way from food but perhaps they just enjoy a really long parachute jump.

4 comments:

TexWisGirl said...

looks like a circus performer!

Joseph JG said...

And it's the biggest circus of them all! They just have to make sure they're supplied with enough spotlights.

Lear's Fool said...

I bet starfish are SUPER annoyed by all these things that can just fly away on them.

Joseph JG said...

Jealous, too!