Bathysaurus

Image: NOAA Okeanos Explorer Program, INDEX-SATAL 2010

You don't get lions and tigers in the sea. You barely get crocodiles, either. Go a little deeper and you even run out of sharks! Here is where Bathysaurus reigns supreme.

They are a kind of Lizardfish, so named because they look a bit like a lizard (but are actually a fish. Just to be ABSOLUTELY sure we all know where we are). Bathysaurus is a particularly terrible member of the family but dinosaur, meaning "terrible lizard", was already taken. So they had to make do with Bathysaurus instead, meaning "deep lizard".

Image: Museum of Comparative Zoology, Harvard University

Bathysaurus is the biggest, meanest fish in its domain, capable of eating pretty well anything it comes across. The whole world is one, big platter. The good news is that they don't appear to harbour nuclear weapons. Refining uranium to the necessary purity is really difficult already, doing it in the dark must be nigh on impossible.

In their damnable crusade to wipe out all life, Bathysaurus must rely on a more traditional weapon; a jaw full to overflowing with teeth. Teeth for killing. Teeth for intimidation purposes. Some more teeth because "teeth is cool". And then a few stashed away for a rainy day because they're quite prudent about that sort of thing.

They even have teeth on their tongue! Never kiss a Bathysaur.

There are two species in the Bathysaurus genus.

Image: NOAA
Bathysaurus mollis

The Highfin Lizardfish, Bathysaurus mollis, can reach up to 80 cm (31 in) long and prefers depths of at least 2,000 metres (6,560 ft). They live in tropical and more northerly, temperate waters across the world  They've never been seen in the tropical, eastern Pacific, though.

The other one is the Deepsea Lizardfish, Bathysaurus ferox. This one reaches up to 65 cm (26 in) long and usually lives at depths between 1,000 and 2,500 metres (3,280 to 8,200 ft). They've been found all over the place.

Image: NOAA Okeanos Explorer Program, INDEX-SATAL 2010
Bathysaurus forex

Bathysaurs don't often do much, preferring to rest on the ocean floor with just their faintly dismayed facial expression for company. I know the feeling...

Of course, they do have to get to work sometimes... and since Bathysaurs are synchronous hermaphrodites - bearing both male and female parts at the same time - they have a little more work to do than most.

Larval Bathysaurs are thought to float around not far from the water's surface, all tiny and getting eaten by a huge array of predators. Soon they will grow, descend to the darkest depths and take their rightful place at the top of the food chain.

Better to rule in Hell, right?