
Scientists drop cow carcass into ocean and are floored by creatures that appear
Scientists who dropped a cow carcass 1,600 metres into the ocean have been left stunned by a group of surprising visitors. It's estimated that only a quarter of the entire ocean seabed on Earth has been mapped. That often means there are weird and wonderful creatures lurking in the deep.
And that's what a group of scientists found during an experiment in the South China Sea, which roughly spans from Singapore to the Strait of Taiwan. They plunged a cow carcass 1,629 meters into the depths near Hainan Island to investigate what would happen. To their astonishment, an elusive shark species, not previously recorded in this region, appeared on the scene. Eight Pacific sleeper sharks (otherwise known as Somniosus pacificus) were caught on camera enjoying the free meal.
Another surprising aspect of the encounter was the sharks' behaviour, predation that appeared to involve a form of queuing. In the study that's been published in Ocean-Land-Atmosphere Research, it explained that the sharks up front would give up their spots to sharks coming to the carcass from behind.
Han Tian, from the Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory in China, said in a statement: "This behaviour suggests that feeding priority is determined by individual competitive intensity, even in deep-water environments, reflecting a survival strategy suitable for non-solitary foraging among Pacific sleeper sharks."
The sluggish Pacific sleeper shark is thought to live in the North Pacific, spanning from Japan to Mexico and dwelling at depths of up to 2,000m near continental slopes and shelves.
In terms of prey, Sleeper sharks eat a range of surface and bottom animals, such as crabs, salmon, octopus, rockfish, and squid, although it's unknown if they take seals live or as carrion.
According to data gleaned from tagging in the Northeast Pacific, some sleeper sharks often ascend and descend at speeds of more than 200 meters per hour.
In the day, they moved below the photic zone (the upper portion of the ocean where light can penetrate) and came up to the surface at night.
The scientists in the latest experiment also discovered that sharks over 8.9 feet were most aggressive in their attacks on the carcass when compared to the smaller animals, the latter of which displayed circling behaviour.
Han added that this aggression could indicate that the region contains "abundant food sources", but questions remain over what they could be, describing the conundrum as "intriguing".
In the study, it was noted that the sharks demonstrated eye retraction while they were feeding. It posited that this was likely a "protective adaptation", as they don't have a nictitating membrane found in other species.
Also noted was that some of the animals, which are related to Greenland sharks, had parasites (akin to copepods, although they were unidentified).
Speaking about the sharks' habitat, Han added: "Although Pacific sleeper sharks have also been found in the deep waters of their typical distribution range in the North Pacific, their frequent occurrence in the southwestern region of the South China Sea suggests that our understanding of this population remains significantly limited."
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11-07-2025
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Scientists drop cow carcass into ocean and are floored by creatures that appear
In an experiment conducted in the South China Sea, scientists plunged a cow carcass into the ocean to investigate what would happen and were left stunned by eight surprising visitors Scientists who dropped a cow carcass 1,600 metres into the ocean have been left stunned by a group of surprising visitors. It's estimated that only a quarter of the entire ocean seabed on Earth has been mapped. That often means there are weird and wonderful creatures lurking in the deep. And that's what a group of scientists found during an experiment in the South China Sea, which roughly spans from Singapore to the Strait of Taiwan. They plunged a cow carcass 1,629 meters into the depths near Hainan Island to investigate what would happen. To their astonishment, an elusive shark species, not previously recorded in this region, appeared on the scene. Eight Pacific sleeper sharks (otherwise known as Somniosus pacificus) were caught on camera enjoying the free meal. Another surprising aspect of the encounter was the sharks' behaviour, predation that appeared to involve a form of queuing. In the study that's been published in Ocean-Land-Atmosphere Research, it explained that the sharks up front would give up their spots to sharks coming to the carcass from behind. Han Tian, from the Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory in China, said in a statement: "This behaviour suggests that feeding priority is determined by individual competitive intensity, even in deep-water environments, reflecting a survival strategy suitable for non-solitary foraging among Pacific sleeper sharks." The sluggish Pacific sleeper shark is thought to live in the North Pacific, spanning from Japan to Mexico and dwelling at depths of up to 2,000m near continental slopes and shelves. In terms of prey, Sleeper sharks eat a range of surface and bottom animals, such as crabs, salmon, octopus, rockfish, and squid, although it's unknown if they take seals live or as carrion. According to data gleaned from tagging in the Northeast Pacific, some sleeper sharks often ascend and descend at speeds of more than 200 meters per hour. In the day, they moved below the photic zone (the upper portion of the ocean where light can penetrate) and came up to the surface at night. The scientists in the latest experiment also discovered that sharks over 8.9 feet were most aggressive in their attacks on the carcass when compared to the smaller animals, the latter of which displayed circling behaviour. Han added that this aggression could indicate that the region contains "abundant food sources", but questions remain over what they could be, describing the conundrum as "intriguing". In the study, it was noted that the sharks demonstrated eye retraction while they were feeding. It posited that this was likely a "protective adaptation", as they don't have a nictitating membrane found in other species. Also noted was that some of the animals, which are related to Greenland sharks, had parasites (akin to copepods, although they were unidentified). Speaking about the sharks' habitat, Han added: "Although Pacific sleeper sharks have also been found in the deep waters of their typical distribution range in the North Pacific, their frequent occurrence in the southwestern region of the South China Sea suggests that our understanding of this population remains significantly limited."


Metro
05-07-2025
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Rare footage has been capture of giant Pacific sleeper sharks feeding on the ocean floor. Scientists observed the fascinating scramble after dropping a dead cow into the South China Sea near the island of Hainan. Pacific sleeper sharks are rarely spotted that far south, with the giant species usually preferring the colder waters of the North Pacific. The discovery also extends their known range, the Economic Times reported. The incredible footage appeared to show the predators queueing to feed from the bovine carcass in a hierarchical system. Individuals approaching the carcass from behind appeared to take precedence over those in front already feeding. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Researchers from Sun Yat Sen University in Guangzhou and Southern Marine Science and Engineering Guangdong Laboratory lowered the bovine carcass to a depth of 1,629 metres and placed cameras to observe the behaviour of marine animals. They were surprised to find huge sleeper sharks among those gathering for the meat. The large species, which can grow to nearly four metres long, is usually found in the North Pacific, including in the Bering Sea and in the Gulf of Alaska. Pacific sleeper sharks are thought to be both scavengers and successful stealth predators as they make little noise underwater. Interestingly, all the sharks captured feeding from the cow carcass were females, possibly indicating the area may serve as a nursery ground for large shark species. Other shark species including the megamouth shark are known to have female bias in the South China Sea. Pacific sleeper sharks can live in depths as low as 2,000 metres below sea level. According to the Shark Research Institute, they prefer continental shelves and slopes, where they rely on stealth predatory behaviour and scavenging. While they are typically found in the icy waters of the North Pacific and near the Arctic Circle, the latest study shows they can range much further south. Very rare, scientists say, given that Pacific sleeper sharks are thought to prefer far colder waters, such as in the Bering Sea and Baja California. The discovery in the South China Sea considerably extends the known range of the species. More Trending Because of the depth of their typical habitat, much remains unknown about Pacific sleeper sharks, including exactly how they feed and reproduce. However previous sightings of the rare species in the southern hemisphere have been known. A huge Pacific sleeper was spotted in the Tonga Trench in January of this year. The unusual discovery was found at a depth of around 1,600 metres where water temperatures are usually around 2.5C. Get in touch with our news team by emailing us at webnews@ For more stories like this, check our news page. MORE: The Dalai Lama issues statement to China ahead of his 90th birthday MORE: Donald Trump says a group of 'very wealthy people' want to buy TikTok MORE: Driver left dangling over edge of a bridge after massive landslides in China