Gulper eels can expand their mouths to crazy dimensions, creating a massive net to scoop up their prey. Their lower jaws are estimated to be about a quarter of the total length of the eel itself!

Male anglerfish are only about a tenth of the size of their female counterparts. They swim long distances to find their mate, and when they do, the male bites on and fuses itself to the female. There, the male will slowly dissolve, becoming dependent on the female host for nutrients, and providing the female with sperm in return. It’s far from a monogamous relationship though—female anglerfish have been spotted with several males attached to them.

Whale sharks are known to take deep dives into the ocean twilight zone, as deep at 1,800m. The extreme depths of these dives make scientists thing that whale sharks visit the OTZ for more than just food—perhaps to cool down, remove parasites, save energy, or even calibrate their internal navigation!