Wednesday 21 March 2018

Bony-eared Assfish

Image: Royal BC Museum
Acanthonus armatus
Now, that's just rude.

This poor, blameless soul who never hurt anyone is a Cusk Eel who lives in depths of up to 4,500 metres and reaches at least 38 cm (15 in) long.

Image: R. Mintern
Like many of the fish who live in Mother Nature's damp basement, he's extremely pale and flabby. Not that that's an excuse for name-calling.

The real excuse seems to come from its scientific name, Acanthonus armatus. The Armatus bit means 'armed,' not because the Assfish has actual arms or guns or whatever, but because he has spines on his gills. Those are probably the bony ears. Acanthonus, meanwhile, could mean 'prickly hake,'—a hake being a sleek, mean-looking relative of the cod—but it could also mean 'prickly donkey.' So it's that kind of ass.

Thankfully, the Bony-eared Assfish is oblivious to all of this. The fact that he has the smallest brain-to-body weight ratio of any vertebrate may or may not have something to do with this.

I'm sure he's lovely once you get to know him.


Maria Thulin said...

Did you see my question or was it just by chance I got the answer right away? Anyhow, thank you, now I know. It´s the Bony-eared Assfish who has the smallest brain-to-body weight ratio of any vertebrate. Who could have guessed? :) Or that it even exists a Bony-eared Assfish?

Joseph JG said...

It was a coincidence! I've had this guy on the list for ages and I actually forgot all about the brain thing. At least, I think I did. Maybe some part of my brain asked the same question and another part knew the answer and they decided to surprise me.

Maria Thulin said...

Who knows what the different brainparts do behind your back when you´re not looking....
As we`re still talking brains; what is the smallest brain all categories? Mabye it is hard to draw the line between a very small brain, and just a bundle of nervs? (I just realised that your blog mabye isnt a answering-service for all kinds of strange questions. If you don´t no, never mind, I´m just curious.)

Maria Thulin said...

Should have been "don´t know", not "don´t no"

Maria Thulin said...

Just saw your answer about the brain size under the trilobite beetle. Didn´t mean to repeat the brainquestion again and again...

Joseph JG said...

No problem!

So I looked a few things up and it sounds like a brain is "a centralised concentration of nerve cells at the front end of an animal."

That means your bundle of nerves would actually count as a brain. The only multi-cellular animals that lack a brain are sponges (who lack a nervous system) Cnidaria (jellyfish, etc.) and echinoderms (starfish, etc.). The last two have nerve nets, so there're no concentrations or bundles.

The very smallest brain probably belongs to some kind of roundworm. Scientists do a lot of research on one particular species called Caenorhabditis elegans and it's entire body is made up of EXACTLY 959 or 1031 cells depending on sex.

Given that these are active worms who crawl around eating bacteria, you can imagine there aren't many cells left over for their brain. And perhaps there are even smaller ones out there!

Maria Thulin said...

Thank you!
Yes, I remember "C. elegans"! They used it because it had so few and big nerves that they could study nerv by nerv. Or even cell by cell.
Amazing what the smallest animals still can do with their very small brains. But mabye that what big-brained animals like whales and elefants think about us relativly small-brained humans :)