Also known as the Gulper Eel, this deep-water oddity can expand its mouth to incredible proportions, acting like a huge net to scoop up prey.

By Helen Pilcher

Published: Wednesday, 08 February 2023 at 12:00 am


In 2018, researchers controlling a remotely operated vehicle in Hawaiian waters stumbled across the best view to date of this deep-sea oddity. Spotted a mile down in the Papahānaumokuākea Marine National Monument, the critter looked like a sinister sperm, with its black, bulbous head and a lithe, whip-like tail. Without warning, its head then began to inflate and wobble, before morphing into a gaping pair of jaws, and then into a more streamlined form, before it disappeared into the darkness.