It's incredibly rare.
So little is known about them.
It lives very deep below a thousand metres.
It's called a hairy anglerfish,
because it has these long, bristly fin rays that make it look quite hairy.
We have only one specimen in our collection.
It's the biggest one that's ever been found.
One of the reasons why it looks quite big is it has a very big bulging stomach.
And we're fascinated to know what's inside.
We don't want to cut it open because it's such a rare specimen,
we don't want to damage it.
This is where the head is,
I can feel the hard, bony jaw of the fish
and it curls around and then the tail is there.
The CT scan's like a three dimensional X-ray.
So we can look at the stomach contents from every angle, and we can examine it
in a lot more detail
This is the mouth of the anglerfish with some teeth.
These are just preliminary shots.
And once we've actually scanned the specimen and reconstructed the data,
we should be able to see this in a full 3D volume.
The most important use of the CT scanner is to be able to look really
intimately into the insides of an animal, but we're not doing any damage to it.
There we are.
That ball thing is one of its eyes.
Is that the eye of the anglerfish?
The anglerfishes eye is up here.
Okay.
There's its mouth and its teeth.
It probably ate it head first, because this thing probably came in to look at the light
the anglerfish has, and then the anglerfish grabbed it
and swallowed it.
And it stomach has expanded to sort of fit it all in.
And these bright bits here that seem to be a lot more dense
than the rest of the bone.
They're the ear bones.
They call them otoliths. And they're very distinctive.
They've got very unique diagnostic features.
So it might be possible to tell exactly what species it is by getting
a good look at those.
We were able to get a really
lovely image of the prey fish's otoliths.
We sent that to the world expert in otoliths
and that gave us a real helping hand with the whole investigation.
And it's rouleina attrita.
The softskin smooth-head.
Here at the Natural History Museum, we have one of the biggest and best
collections of deep sea and mid-water fishes from the Atlantic in the world.
And so, of course, we already have specimens of rouleina attrita.
They've been a bit bashed up during the capture,
but this gives you a rough idea of the size
and sort of general shape of the fish inside the anglerfish.
And you can see looking at it
some of the features that are obvious on the scan.
You can see the big eye with the big lens in the middle.
It's a bit like, I don't want to bend it too much, but it's sort of like that inside.
Everything fits, the size fits,
all the fin ray counts fit.
And most importantly, and this is the thing that narrows it down
to the exact species, is the number of bones in its backbone.
We ended up having to scan the specimen three times, but the final results
we got was so beautiful that it was worth it
Now, when people ask what's inside its stomach, I can give them a definite answer.