Age: Appears not to have bothered to evolve for at least six million years.
Appearance: One seriously evil-looking fish.
Whoa! I just did an image search. What on Attenborough's sweet blue earth is that? That's a megrim, a left-eyed flatfish coming soon to a plate near you.
Left-eyed? As in both its creepy little eyes are on the left-hand side of its face.
It's like a Hieronymus Bosch painting of a fishmonger's nightmare. Yup.
And I'm going to have to eat this demonic abomination? Well, no, but you're going to be encouraged to try it.
Am I being punished for something? In a sense, yes, we all are. We've overfished the "Big Five" – cod, haddock, tuna, salmon and prawns – and now supermarkets and marine conservationists are hoping to steer us towards more sustainable seafood. Like the megrim.
And how exactly do they plan to do that? Puree them down and serve as healthy fish smoothies? Not yet, but on Friday Sainsbury's customers looking to buy the "Big Five" will be offered – for free – a choice of five lesser-known sustainable fish: the coley, pouting, rainbow trout, mackerel and megrim.
As in "Why not try this delicious nightmare fish?" More or less.
Why would anyone say yes to that? For one thing, megrim is much cheaper than its cousins the lemon and Dover sole.
So are dead mice. Fair point. But for another thing, it actually tastes surprisingly good. So good, in fact, that in Spain the megrim is considered to be something of a delicacy, and imported from British shores in large quantities.
Whoa, hold on, it's British? Mostly, yes. Healthy stocks of megrim are found in the Irish Sea and the Western Channel, meaning it's not only cheap, eco-friendly and tasty, but local.
I'm still not touching it. Nor am I.
Do say: "Do your bit for marine conservation. . ."
Don't say: ". . . by eating this other, even uglier fish to extinction."
