During an expedition to study the deep ocean in 2017, scientists pulled up something unexpected from the abyss. It was a fish with a mouth full of needle-sharp teeth, a long eel-like body, and a reptilian head.
“It’s a strange-looking creature,” says John Pogonoski, an ichthyologist (fish scientist) with the Australian National Fish Collection. He’s the one who found the fish while aboard a research vessel off the coast of eastern Australia. But, he adds, “I knew straightaway what it was.” The animal in question was a deep-sea lizardfish (Bathysaurus ferox), one of the world’s deepest ocean-dwelling predators.
These fish live at depths of 600 to 3,500 meters (2,000 to 11,500 feet). Sunlight doesn’t reach this part of the ocean. Creatures like B. ferox have adapted to survive in the cold, pitch-black environment. Its bulging eyes, for example, help it see in the dark. That could make it easier for the fish to spot bioluminescent prey, such as deep dwelling shrimp, squid, or jellyfish. Such animals give off their own light through a series of chemical reactions.
Lizardfish, which can grow up to 0.6 m (2 ft) long, are apex predators in the deep sea. Few animals try to eat them. They hunt by lying in wait. Hidden under a layer of sand or mud, they ambush any animal that swims within reach. Once a lizardfish catches a meal, its flexible teeth help push the unlucky prey farther back into the fish’s mouth. There’s no chance of escape, says Pogonoski.