Sharks can be really scary. But while most of us are afraid of sharks (such as the big white), few know that they can hide in deep waters. There, at a depth of 3,000 meters, live these monsters of the sea – the elusive feline demon shark, a deep-sea fish-dog, and a ghost shark. With their strange teeth and evil eyes, they look like characters from a Tim Burton movie. But perhaps the most terrible fact is that we know very little about them.
Good year for researchers
To shed light on these mysterious creatures, in September of this year, a research expedition was organized to the western coast of Scotland. Her goal was to collect samples for the project to find out the behavior, feeding and movement of deep-sea sharks.
The expedition took two weeks and was rather difficult. Researchers collected samples at a depth of 500 to 2000 meters. Many scientists have previously worked in this region for a long time. Fortunately for them, it was a good year. Every day, scientists managed to get from four to five samples, each with its own distinctive oddities.
Most of us have never seen deep-sea sharks. But even though they are hidden under a layer of water that creates impenetrable darkness for the human eye, they are a group of very diverse sharks. When looking at them, it is understandable why many of these fancy fish got their disgusting names.
The inaccessibility of the ocean depths limited our scientific understanding of these creatures. These secrets only strengthen their complex biology.
Deep-sea sharks can be divided into three groups: cat-like, karhirinoobraznye and chimeric. The first are fish-dogs (Katrans), the second are cat sharks, and the third are shark ghosts. While catrans and cat sharks are real sharks, ghost sharks belong to the chimera group. These are cartilaginous fishes, closely associated with sharks.
The most common family in Scottish waters is the cat shark. Researchers managed to find one of its species – the feline demon shark (Apristurus). These creatures have thin bodies with a relatively large head and narrow eyes, thanks to which this species got its name. They are especially difficult to identify, and during the expedition, scientists were faced with a species that had not previously been described. Scientists hardly have an understanding of how many species there may be in this group, not to mention their biology and ecology. It is believed that they feed on shrimp, but still very much remains unknown.
Katrans are usually stocky, their skin resembles sandpaper. They have large eyes, and in the jaws lined rows of teeth. In Scottish waters, scientists managed to find a really large variety of these fish – from a 30-centimeter shark Etmopteridae, to a half-meter-long sheet shark. Their diet is very extensive. They eat whale carcasses that fall to the bottom, as well as small fish and shrimp.
Real horror: the ecosystem is in danger
These alien-looking creatures actually make up most of the inhabitants of deep waters. About half of all sharks known to scientists live there. In addition to the ghost shark and feline demon shark, the scientists also found a 2.5-meter sofa shark.
And although the appearance of most of these fish can scare some particularly impressionable people, the horror story of the real life of these creatures actually creates human activity. Deep-sea fishing, mining and environmental pollution pose a real threat to deep-sea ecosystems. Given the exceptionally slow growth rate of these sharks, the longevity and low reproduction rate, it is doubtful that these species can survive in this situation.
But without knowledge of their fundamental biology and behavior patterns, it is very difficult to assess how much such human activity will affect them. Perhaps these are not the cutest animals on our planet, but they play an important role in the ecosystem – they accumulate carbon dioxide and are an important link in the food chain.
Unfortunately, without appropriate conservation measures, these deep-sea ghosts and demons can become nothing more than heroes of myths and legends.