BY: PHILIPPE DE JOCAS
How old is old? Modern humans first appeared about 200,000 years ago. The first dog-like animals snuffled around about six million years ago. Fifty five million years ago, the oldest monkeys swung in the trees. Early crocodiles rubbed elbows with dinosaur ancestors back in 200 million BCE. Cockroaches and dragonflies took to the air 120 million years before that. But all of these pale in comparison to one of the oldest and toughest survivors on our planet.
Cue the Jaws theme.
Sharks as we know them have comfortably cruised our oceans for more than 425 million years, predating even the earliest amphibians. Often upstaged by flashier predators but never outdone, they’ve survived some of the worst extinction events on Earth and soldiered on. Prehistoric sharks throughout the fossil record often sported strange and sometimes ostentatious features, but they also possessed recognizably “shark-y” traits that have allowed them to persevere through some of the worst catastrophes in Earth’s history.
Today, there are 470 species of known sharks. The biggest and most iconic man-eaters – great whites, tigers, bulls, and hammerheads – constitute the minority of shark species; the vast majority of sharks are only a few feet long and not inclined to go after humans. What sets sharks apart from other predators is their sheer adaptability. Slow-moving, long-lived species lurk below the polar ice caps, while fast-moving torpedo-shaped sharks prowl coral reefs. Some particularly elusive sharks eschew the warm upper ocean entirely in favor of the cold, dark abyss of the deepest sea.
Of these deep-diving species, few are more mysterious than the shadowy chimaeras, also known as ratfish, spookfish, or, appropriately, ghost sharks. They’re about as far from the big, nasty man-eaters as you can get. Close cousins of sharks, scientists believed that the chimaeras branched off from other members of the shark tree some four hundred million years ago and remain unchanged living fossils today. They slither through the deep ocean, about 8,500 feet down from the surface, and hunt smaller fish and crustaceans with electro-receptive cells.
Chimaeras are far from beautiful or elegant, even in their element; their pale white skin, watery eyes, and criss-crossed patterns of electrically-sensitive skin gives them the appearance of a stitched-together Frankenstein monster. The fact that this mismatched-looking creatures carries its penis on its head only adds to its monstrous reputation. Although deep sea fishers and scientists have occasionally dredged up chimaeras, the pressure changes involved in the ascent destroys their fragile internal systems and kills them. No one had ever seen one alive… until now.
In 2011, the University of California conducted a deep sea ROV (remotely operated vehicle) dive off the coast of Hawaii as part of a routine geological analysis of the seabed. During their otherwise normal descent, the ROV made a new friend – a pointy nosed blue chimaera. Evidently curious about the strange invader, the ghostly fish investigated the machine for several minutes, nosing up against it before swimming away to hunt among the rocks.
The footage, which only surfaced in December of 2016, would, itself, be remarkable: it’s not every day that you get to see a hitherto-unknown species swimming in the deep ocean. Not only did scientists learn more about the behavior of chimaeras, but the footage also revealed that chimaeras ranged farther than anyone had thought possible. Previous knowledge ascertained that the chimaeras primarily stuck to the southern oceans; none had ever been caught as far north as Hawaii. Scientists are crossing their fingers and hoping to repeat this miracle in the near future to uncover more about the strange and mysterious lives of real-life ghosts.
