Scaly-foot snail: The armor-plated hermaphrodite with a giant heart that lives near scalding deep-sea volcanoes and never eats
When you buy through links on our articles, Future and its syndication partners may earn a commission.
QUICK FACTS
Name: Scaly-foot snail (Chrysomallon squamiferum)
Where it lives: Hydrothermal vents on the seafloor of the Indian Ocean
What it eats: As an adult, it doesn't! All of the snail's nutrition is generated internally, by endosymbiotic bacteria — microbes that live in the snail's gut.
The scaly-foot snail, or volcano snail, possesses something unique among gastropods: a coat of protective armor covering its foot, made from hundreds of overlapping iron-infused scales. It fortifies these scales with minerals absorbed from the hot liquid spewed by hydrothermal vents and black smoker chimneys at the bottom of the Indian Ocean, where water can reach temperatures of 752 degrees Fahrenheit (400 degrees Celsius).
Related: Elusive colossal squid finally caught on camera 100 years after discovery in world 1st footage
Within the snail's scales, sulfur reacts with iron ions to form iron sulfide nanoparticles. Further toughening the snail's defenses is an outer layer of iron sulfide in its shell, making it the only known multicellular animal to strengthen its skeleton with iron. When the National Museum of Wales acquired a pair of specimens in 2015, curators were told to avoid using any water in the preservative solution, because otherwise the snails would start to rust.
Underneath all that armor, the scaly-foot snail has a big heart — the largest in the Animal Kingdom relative to the animal's size — making up about 4% of the volume of its entire body. In waters where oxygen levels are low, that enormous heart also supplies oxygen to the symbiotic bacteria that live in the snail's esophageal gland and act as a built-in food factory. The snails, whose shells measure about 2 inches (5 centimeters) in length on average, are sometimes called "sea pangolins" for their resemblance to the armor-plated land mammal.
Individuals have both male and female sex organs. They creep along the ocean bottom at depths of approximately 1.7 miles (2,780 meters), and are known from just three hydrothermal vent fields to the east of Mauritius, an island off the southeastern coast of Africa.
RELATED STORIES
—Bone collector caterpillar: The very hungry caterpillar of your nightmares
—Mount Kaputar pink slug: The giant hot-pink mollusk found only on a single, extinct volcano
—Leaf sheep: The adorable solar-powered sea slug that looks like Shaun the Sheep
While the snails' potential habitat adds up to around 0.1 square miles (0.3 square kilometers), the range where they are currently found covers just 0.008 square miles (0.02 sq km). But even this tiny sliver of the deep ocean is becoming unsafe for the snails, due to human activity.
In 2019, the International Union for Conservation of Nature (IUCN) added scaly-foot snails to its Red List of life at risk of extinction. The snails became the first animal to be listed as "endangered" due to threats to two of its three habitat locations from deep sea mining.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Forbes
3 days ago
- Forbes
World Reef Awareness Day 2025: Bringing Corals Back To Life
Coral reefs in the Maldives getty On June 1st, the world celebrated World Reef Awareness Day 2025 under the urgent theme: 'Bringing Corals Back to Life.' This day highlights the indispensable role coral reefs play in sustaining marine life and coastal communities and the existential threats they now face. According to the Coral Reef Alliance, coral reefs, which cover less than 1% of the ocean floor, support approximately 25% of all marine species. Beyond biodiversity, they provide food, livelihoods, and coastal protection for over one billion people globally. However as time progresses, what is notable is that these ecosystems are collapsing. According to the National Oceanic and Atmospheric Administration, the ongoing 2023–2025 global coral bleaching event is the most extensive on record. To further give light to the situation, the International Coral Reef Initiative indicated that, bleaching-level heat stress has now impacted 84% of the world's coral reefs, with damage recorded across 82 countries, territories, and economies. For comparison, only 21% of reefs experienced similar stress during the first global bleaching event in 1998, rising to 37% in 2010, and 68% during the prolonged third event between 2014 and 2017. Scientists have already described the current fourth global bleaching event as 'unprecedented' as early as May 2024. In fact, the widely-used Bleaching Alert System had to expand its scale, adding new Levels 3 through 5 to capture the escalating risk. Previously, Level 2 indicated potential mortality for heat-sensitive corals; Level 5 now signals a risk where more than 80% of all corals on a reef could die from sustained bleaching conditions. The World Wildlife Fund article also warns that if current warming trends continue, up to 90% of coral reefs could disappear by 2050. In response, restoration strategies are gaining traction, for example, as reported in Time Magazine, Mars Inc. is making waves in reef rehabilitation. the company has planted over 1.3 million corals in the past 15 years. Leading these efforts is David Smith, the company's chief marine scientist, who ensures that each coral restoration project is grounded in rigorous scientific research. Mars Inc's "reef stars" hexagonal steel structures are seeded with sand and coral fragments has helped Indonesia's Hope Reef rebound from just 2% coral cover to over 70%, with fish populations surging by 260%. Meanwhile, researchers are developing heat-resistant hybrid corals better suited for warming seas, according to National Geographic. Technological solutions are also advancing, according to NOAA, scientists are testing rubble stabilization for the first time in Hawaii's coastal waters as a method of coral restoration, and early results are promising. The technique involves anchoring loose and broken reef fragments to the seafloor, providing a stable foundation for coral regrowth. This process has already helped revive disintegrated reef systems, offering them a renewed chance at recovery. World Reef Awareness Day is more than symbolic as it is a call to urgent action. Without intervention, the planet risks losing one of its most vital ecosystems as a result it is essential to restore them, not only an environmental imperative but essential for future food security, biodiversity, and climate resilience.
Yahoo
4 days ago
- Yahoo
Sperm whale hit by vessel, washes ashore near Seaside
PORTLAND, Ore. (KOIN) — A 53-foot sperm whale, which was struck by a vessel, washed ashore north of Seaside on Thursday afternoon, days after it died, the Sunday. The adult male was first reported dead on May 23 about 15 miles offshore. Four days later, the whale was about 7 miles offshore. Once it washed ashore between Del Ray and Sunset Beach, officials were able to do a necropsy that revealed the whale died after being hit by a vessel. The whale will stay on the beach to decompose and 'provide a nutrition boost to the local ecosystem,' authorities said. The whale will provide food for turkey vultures, bald eagles and coyotes 'for quite some time.' Astoria police wear 'The Goonies' patches in honor of Oregon film's 40th anniversary However, people should stay away from the whale. 'Marine mammals may spread potential diseases to humans and pets,' the Seaside Aquarium said. Though authorities said the whale was an adult male, they did not provide an estimated age. However, these male sperm whales can reach 60 feet and more than 40 tons while living up to 60 years. Males mature around 50 with a length of about 52 feet. Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
Forbes
4 days ago
- Forbes
Shark Skeletons Aren't Bones. They're Blueprints.
Blacktips are medium-sized coastal sharks commonly found in warm, shallow waters around the world, ... More including the Gulf of Mexico, the Caribbean, and parts of the Indian and Pacific Oceans. Sharks don't have bones. Instead, their skeletons are made from mineralized cartilage, an adaptation that has helped these predators move through the oceans for over 400 million years. A new study takes a deeper look — quite literally — at how this cartilage works. Using a combination of high-resolution 3D imaging and in-situ mechanical testing, a global team of scientists have mapped out the internal structure of shark cartilage and found it to be much more complex than it appears on the surface. The findings not only help explain how sharks maintain their strength and flexibility, but also open the door for developing tough, adaptable materials based on nature's own engineering. The research focused on blacktip sharks (Carcharhinus limbatus) and involved a collaboration between the Charles E. Schmidt College of Science, the College of Engineering and Computer Science at Florida Atlantic University, the German Electron Synchrotron (DESY) in Germany, and NOAA Fisheries. Blacktips are medium-sized coastal sharks commonly found in warm, shallow waters around the world, including the Gulf of Mexico, the Caribbean, and parts of the Indian and Pacific Oceans. They typically grow to about 5 feet (1.5 meters) in length, though some individuals can reach up to 8 feet (2.4 meters). Named for the distinctive black markings on the tips of their dorsal, pelvic, and tail fins, blacktip sharks primarily eat small fish, squid, and crustaceans, using quick bursts of speed to chase down prey. The team zoomed in on their cartilage using synchrotron X-ray nanotomography, a powerful imaging technique that can reveal details down to the nanometer scale. What they found was that the cartilage wasn't uniform. In fact, it had two distinct regions, each with its own structure and purpose. One is called the 'corpus calcareum,' the outer mineralized layer, and the other is the 'intermediale,' the inner core. Both are made of densely packed collagen and bioapatite (the same mineral found in human bones). But while their chemical makeup is similar, their physical structures are not. In both regions, the cartilage was found to be full of pores and reinforced with thick struts, which help absorb pressure and strain from multiple directions. That's especially important for sharks, since they are constantly in motion. Their spines have to bend and flex without breaking as they swim. The cartilage, it turns out, acts almost like a spring. It stores energy as the shark's tail flexes, then releases that energy to power the next stroke. The scientists also noted the presence of tiny, needle-like crystals of bioapatite aligned with strands of collagen. This alignment increases the material's ability to resist damage. Researchers also noted helical fiber structures in the cartilage, the twisting patterns of collagen helping prevent cracks from spreading. These structures work together to distribute pressure and protect the skeleton from failure; this kind of layered, directional reinforcement is something human engineers have tried to mimic in synthetic materials, but nature has been perfecting it for hundreds of millions of years. The intermediale cartilage of a blacktip shark, with arrows highlighting the internal mineralized ... More network that supports and reinforces the structure. Dr. Vivian Merk, senior author of the study and an assistant professor in the FAU Department of Chemistry and Biochemistry, the FAU Department of Ocean and Mechanical Engineering, and the FAU Department of Biomedical Engineering, explained in a press release that this is a prime example of biomineralization: 'Nature builds remarkably strong materials by combining minerals with biological polymers, such as collagen – a process known as biomineralization. This strategy allows creatures like shrimp, crustaceans and even humans to develop tough, resilient skeletons. Sharks are a striking example. Their mineral-reinforced spines work like springs, flexing and storing energy as they swim.' Merk hopes that understanding how sharks pull this off can help inspire new materials that are both strong and flexible, perfect for medical implants, protective gear, or aerospace design. To test just how tough this cartilage really is, the team applied pressure to microscopic pieces of the shark's vertebrae. At first, they saw only slight deformations of less than one micrometer. Only after applying pressure a second time did they observe fractures, and even then, the damage stayed confined to a single mineralized layer, hinting at the material's built-in resistance to catastrophic failure. 'After hundreds of millions of years of evolution, we can now finally see how shark cartilage works at the nanoscale – and learn from them,' said Dr. Marianne Porter, co-author and an associate professor in the FAU Department of Biological Sciences. 'We're discovering how tiny mineral structures and collagen fibers come together to create a material that's both strong and flexible, perfectly adapted for a shark's powerful swimming. These insights could help us design better materials by following nature's blueprint.' Dr. Stella Batalama, dean of the College of Engineering and Computer Science, agreed: 'This research highlights the power of interdisciplinary collaboration. By bringing together engineers, biologists and materials scientists, we've uncovered how nature builds strong yet flexible materials. The layered, fiber-reinforced structure of shark cartilage offers a compelling model for high-performance, resilient design, which holds promise for developing advanced materials from medical implants to impact-resistant gear.' This research was supported by a National Science Foundation grant awarded to Merk; an NSF CAREER Award, awarded to Porter; and seed funding from the FAU College of Engineering and Computer Science and FAU Sensing Institute (I-SENSE). The acquisition of a transmission electron microscope was supported by a United States Department of Defense instrumentation/equipment grant awarded to Merk.
