Rare 'faceless and brainless' fish seen off UK coast

[DetlefK]

3. no skull-capsule, no jaws... but earthworms don't have a face either

I guess, he would just need lips and something like a tongue to suck his food in.

If he can only eat plancton, he doesn't need a stomach, just a colon, like a shrimp.
If his food isn't chemically complicated, he doesn't need a very large liver.
And if the blood vessel structure of his intestines is simple and straightforward, he doesn't need a strong heart either, like an earthworm.
Maybe his internal organs are just too small to see on the picture.