Meet the “ghost shark”, also known as the spookfish. It was captured on film by an autonomous rover in 2009 in the deep sea off the coast of California and images are only now being released to the public.
The species, which features retractable sex organs on its forehead, has never been seen on film before. The individual has been identified by researchers at the Monterey Bay Aquarium Research Institute (MBARI) as Hydrolagus cf. trolli – known commonly as the pointy-nosed blue chimaera.
The “cf.” in its species name indicates that its physical characteristics closely match the official species description for Hydrolagus trolli, but without DNA evidence, they can’t be sure. In fact, there’s also the possibility that this isn’t just the first ever footage of a live Hydrolagus trolli – it could be showing us an entirely new species of ghost shark. But because these fish are usually too large, fast, and agile to be caught by deep-sea roving vehicles, it’s going to be incredibly difficult to find out for sure …
This new footage now suggests that the species has a much wider range than anyone had expected, and hints that it could range even further away from its known haunts have made researchers hopeful that it’s not rare – just good at hiding.
Ghost sharks, says the article, split from sharks in the evolutionary tree nearly 400 million years ago. They live on the ocean floor at depths of up to 2,600 metres (8,500 ft). Instead of the conveyer belt of replaceable teeth found in sharks, they have a permanent set of ‘tooth plates’ to grind prey to pieces. Those deep grooves in their flesh are called lateral line canals. They may contain sensory cells to help the creatures detect movement in the pitch-black water.