The Black Swallower (Chiasmodon niger) is one of the creepiest fish I’ve ever seen. These little monsters live in some of the deepest darkest depths of the ocean, from roughly 2,000′ down all the way to 9,000′ below the surface.
The thing that makes the Black Swallower especially scary is their ability to swallow fish much larger than them. They only reach 10″ long, so they aren’t an especially big fish but they have a huge mouth. The upper jaw of the Black Swallower is articulated with the skull at the front via the suspensorium, which allows the jaws to swing down in order to swallow much larger prey. The upper and lower jaw are lined with a single row of sharp teeth.
The Black Swallower in the upper right portion of this photo was taken in 2007. The fish measured 19 cm (7.4 in) long was found dead off Grand Cayman. The stomach of the swallower contained a snake mackerel (Gempylus serpens) 86 cm (34 in) long, or four times its length. It isn’t uncommon to find dead Black Swallowers floating like this, while they can consume massive prey they obviously have a limit. This poor guy obviously found his limit.