Slingjaw Wrasse

Image: Mark Rosenstein
Epibulus insidiator

You're at a party, having fun, drinking drinks, nibbling nibbles when suddenly, disaster strikes: they've run out of those little sausages on sticks! What madness is this? What lunacy? What dark forces are at work to deprive us of our little sausages on sticks?

You look around and notice that some, fellow party-goers are walking around with paper plates piled high with gluttonous quantities of little sausages on sticks. They've hoarded them, the rascals!

Image: maractwin

What to do?

Well, if you've learnt anything from the Slingjaw Wrasse, the answer is clear: you must shoot your mouth off. And I don't mean shout and make a scene, but literally launch your mouth at the little sausages on sticks when no-one's looking. They won't suspect a thing!

You certainly wouldn't suspect the Slingjaw Wrasse. They look like normal, attractive, well-adjusted fish. They could be your neighbour, your colleague, your postman...

Image: Randall, J.E.
Young slingjaw

Youngsters are brown with white stripes and very secretive. They like to hide among corals and rocks in their reef homes.

As they get older they lose their white stripes and may be taken by the spirit of adventure. They might swim to the surface to hang out among drifting leaves and plants, using their brown colour as camouflage. If the plants are yellow, they can simply turn yellow! Now they drift around in relative safety until they discover a new reef.

Image: FishWise Professional
Female

This "caution to the wind" style of dispersion means that Slingjaw Wrasses have managed to spread across half the world, from east Africa and Madagascar, across to Japan, down to Australia and all the way out to Hawaii.

These young wrasses all grow up into females who are usually brown, sometimes yellow. When they get older and even bigger, they turn male. It sounds odd, but this gender switch is a common thing among wrasses. They're all at it!

Image: Alain Feulvarch
Male

Males can reach more than 50 cm (20 in) long and are quite colourful. If he's a grand, territory-owning male in full pomp he'll be very colourful, indeed. It's like having a great big feather in your cap so everyone can see how important you are.

Despite the bright colours, Slingjaw Wrasses go by the rather sinister scientific name Epibulus insidiator. Epibulus comes from the Greek epi meaning "over" or "in front" and boleo meaning "to throw". Meanwhile, an insidiator used to be someone who lurked and lay in ambush. What a cool word! Unfortunately it isn't used any more. We still have 'insidious' but, shockingly, I can't even find a single metal band called INSIDIATOR. I thought there would've been at least five or six in the 80's alone.

But what is all this about throwing and lurking, hmm? Well, you know how some people can throw their voice? Slingjaw Wrasses just throw their entire mouth.

Video: Roman S.

They don't do it to imbue nightmarish, humanish dolls with evil spirits in the name of entertainment. They do it... to kill. I mean, they do it to eat small fish and crustaceans.

Slingjaw Wrasses creep around the reefs, actively hunting prey. They peer into rocky crevices, they carefully examine coral branches, they swim on their side and peer under corals and stones. When they spot something tasty, they launch the attack. And that means launching their jaws.

Video: Wainwright Lab

Their meal is none too willing to come to the mouth, so the mouth shall have to go to the meal. The Slingjaw's jaws are not firmly attached to their skull, so they're able to fling them out until they're at the end of a tube about half as long as their body.

With their face thus Seahorsied, they can ambush prey and suck them out from nooks and crannies. It all happens very quickly, and unlike Seahorses, the Slingjaw Wrasse is polite enough to reel his mouth back in when he's done with it.

Image: Mark Rosenstein
The face insidious

So the thing that lurks, the thing that creeps, the thing that lies in ambush is not the actual fish at all. The fish swims around bold as brass. It's the mouth. The monstrous mouth that secretly awaits, hidden on a neighbourly fish face.

Creepy. Insidiatory?