The “deepest ever” living fish have been discovered, scientists believe.
A UK-Japan team found the 17-strong shoal at depths of 7.7km (4.8 miles) in the Japan Trench in the Pacific – and captured the deep sea animals on film.
The scientists have been using remote-operated landers designed to withstand immense pressures to comb the world’s deepest depths for marine life.
Monty Priede from the University of Aberdeen said the 30cm-long (12in), deep-sea fish were surprisingly “cute”.
The fish, known as Pseudoliparis amblystomopsis, can be seen darting about in the darkness of the depths, scooping up shrimps.
The researchers have been looking at the Hadal zone – the area of ocean that sits between 6,000 and 11,000m (20,000-36,000ft). It consists of very narrow trench systems, most of which are found around the Pacific Rim.
The researchers are able to explore them using specially designed remote operated vehicles that are fitted out with cameras.
Professor Priede, director of Oceanlab, said: “There is the question of how do animals live at all at these kinds of depths.
“There are three problems: the first is food supply, which is very remote and has to come from 8km (5 miles) above.
“There is very high pressure – they have to have all sorts of physiological modifications, mainly at the molecular level.
“And the third problem is that these deep trenches are in effect small islands in the wide abyss and there is a question of whether these trenches are big enough to support thriving endemic populations.”
But this species appears to have overcome these issues, added Professor Priede.
“We have spotted these creatures at depths of 7,703m (25,272ft) – and we have actually found a massive group of them.
“And this video is pretty tantalising – the fact that there are 17 of them implies that they could well be a family group, begging the question of whether some form of parental care exists for these fish.”
The researchers said they were surprised by the fish’s behaviour.
“We certainly thought, deep down, fish would be relatively inactive, saving energy as much as possible, and so on,” Professor Priede told BBC News.
“But when you see the video, the fish are rushing around, feeding accurately, snapping at prey coming past.”
Because the fish live in complete darkness, they use vibration receptors on their snouts to navigate the ocean depths and to locate food.
A FEARSOME mutant fish has started killing people after feeding on human corpses, scientists fear.
They reckon that a huge type of catfish, called a goonch, may have developed a taste for flesh in an Indian river where bodies are dumped after funerals.
Locals have believed for years that a mysterious monster lurks in the water. But they think it has moved on from scavenging to snatching unwary bathers who venture into the Great Kali, which flows along the India-Nepal border.
The extraordinary creature has been investigated by biologist Jeremy Wade for a TV documentary to be shown on Five.
He said: “The locals have told me of a theory that this monster has grown extra large on a diet of partially burnt corpses. It has perhaps got this taste for flesh by feasting on remains of funeral pyres. There will be a few freak individuals that grow bigger than the other ones and if you throw in extra food, they will grow even bigger.”
Jeremy discounted theories that crocodiles could be responsible for the carnage before turning his attention to goonches – among the world’s biggest freshwater fish.
He caught one which tipped the scales at 161lb and was nearly 6ft long – a world record weight and far bigger than any landed before.
An 18-year-old Nepali disappeared in the river last year, dragged down by something described as like an “elongated pig”.
But the first victim of a goonch attack was thought to have been a 17-year-old Nepalese boy.
He was killed in April 1988 as he cooled himself in the river.
Witnesses said he was suddenly pulled below the surface.
Three months later a young boy was dragged underwater as his father watched helplessly.
Japanese performing dolphins go on a diet
Dolphins at a marine park in Japan have been put on a diet after developing pot bellies and failing to hit jumping targets.
Staff at Kinosaki Marine World in western Japan became concerned last month when they noticed the aquatic performances of the plumper dolphins were beginning to suffer.
Keepers were confused by their apparent sluggishness and noticed the animals were having problems keeping upright while treading water.
“We were puzzled by their poor performance, then we noticed they looked rounder,” said Haruo Imazu, the park spokesman.
The dolphins were weighed and keepers realised that all 19 had become heavier. Some had put on up to 10kg (22bl) over the summer.
But keepers could not work out why, as their diets had not changed. The creatures were all fed from the same menu – 15kg (31bl) of mackerel mixed with white fish. Then they discovered that the mackerel the dolphins had been eating had become fattier, hence the weight gain.
The dolphins have since been put on a low-fat diet and weight loss programme, including a new exercise regime.