The Ghost Shark is Totally Weird and Awesome

By AT&T Digital Media Productions editorial team

 

There are plenty of oddball sharks in the sea: hammerheads, wobbegongs, megamouths. But descend to the darkest depths, and they start to get really strange. At the bottom of the ocean lurks the elusive and the prehistoric, the weird and the wonderful. Say hello to the ghost shark.

 

What’s in a name?

Formally known as the chimaera, and informally as the “spookfish,” this deep-sea dweller has been around over 400 million years (that’s longer than the dinosaurs!), yet has managed to stay one of the least understood shark species. There are around 50 known breeds, but there could be many more. Living two miles underwater at the bottom of the ocean definitely helps keep the mystery alive.

In Greek mythology, the Chimera was a fire-breathing part goat, part lion, part snake, and sometimes part dragon. Although the ghost shark may not be as multi-talented as the mythical beast, it does pose its own otherworldly set of attributes.

While it may look like a character from A Nightmare Before Christmas due to its patchwork-like skin, the stitching effect forms canals that are thought to help the shark detect movement. The ghost shark lives in darkness, so it relies on those sensors to get around. With its oversized eyes and even bigger gills, this shark swims slowly along the ocean floor, contributing to its ethereal appearance.

Like their shark relatives, the ghost shark has smooth, scaleless skin that is typically a gray or white shade, and is cartilaginous, having no bone skeleton. Unlike their cousins, the ghost shark has only one gill opening, as opposed to the five or seven that most other shark species possess.

 

 

The life of a ghost shark

These bottom dwellers have plated teeth that allow them to efficiently chomp down on the tough shells of crustaceans, their favorite prey. Ghost sharks have only one set of teeth, unlike many shark species, which have several rows of replacements at their disposal. Additionally, the ghost shark’s jaw is fused to its skull, so it can’t be detached for huge great white-style gulps.

Another fascinating departure from average sharks is the retractable sex organs found both on the pelvic fin and the forehead of the male ghost shark. While these are thought to play some role in courtship, it’s unclear exactly what they’re for.

The female lays two leathery eggs after copulation, burying them in sandy, shallow waters. The eggs take eight months to gestate before hatching babies measuring approximately 15 cm (5.9 in) in length.

 

 

Growing up to around three feet long (with the largest known specimen measuring in at just over four feet), males reach maturity at age two or three, with females reaching maturity between four and six. The average ghost shark’s lifespan is around 15 years.

These deep sea divers have been found everywhere except for the Arctic. They’re most abundant off the beaches of Australia and New Zealand, but some species have also been found off the California coast. While most ghost shark species favor smooth ocean floor, the pointy-nose blue chimaera prefers a rocky surface.

Ghost sharks live in relative isolation, but larger fish and other sharks sometimes sneak down to the sea bottom in search of a snack. Thankfully, the ghost shark is well-defended by its seriously venomous, razor sharp spine.

Although the IUCN Red List mentions only one species as vulnerable, and another two as near threatened, the elephant fish chimaera is captured in both New Zealand and Australia, and sold as whitefish fillets. Other breeds are caught as bycatch and released back into the sea. Unfortunately, the ghost shark has a low survival rate, due to the long journey to and from the depths where they are caught.

These underwater aliens are typically broken down into three categories by researchers: long-nose, short-nose and plow-nose. While scientists and researchers have known about chimaeras for a long time, only recently, with the emergence of new technology, have ghost sharks been easily observable in their natural habitat. For now, they stay remain one of ocean's biggest mysteries.

 

Catch up on all the rest of the weirdest and wildest sharks on Earth, only on Discovery.

 

Sources: Science Alert, National Geographic, Florida Museum, Discovery, Shark Trust