April 19, 2025
Mysterious Sea Pigs and Butterflies Found on the Antarctic Ocean Floor
Strange underwater life ranging from hand-sized sea spiders to jelly-like sea pigs to a breeding sea butterfly has been found by Australian scientists investigating the Antarctic ocean floor. Taken aboard the RSV Nuyina icebreaker, these unusual species found at enormous depths provide understanding of life in one of the toughest places on Earth. Special seawater cont...

Australian researchers have reportedly discovered several previously undocumented species on the Antarctic seafloor, including palm-sized spider-like creatures and an eyeless, gelatinous animal known as a “sea pig.” The spider-like species are said to be more closely related to crabs than to spiders, have long legs and compact bodies. Researchers noted that the appearance of these animals can vary when removed from their natural environment. For instance, the sea pig is reportedly more uniform and structured while moving along the seabed than when brought to the surface.

Rare Sea Pigs and Giant Sea Spiders Found in Antarctica

According to an ABC News report, scientists also encountered marine stars roughly the size of a dinner plate and sea spiders with leg spans reaching up to 20 inches. The sea spiders, characterised by long, thin legs and small bodies, were collected using a specially designed “wet well” — a seawater-filled tank on board the research vessel that helps preserve fragile specimens. In one of the ship’s aquariums, a sea butterfly laid eggs, giving researchers a rare opportunity to observe its reproductive process. The team continues to study the behaviour and development of these species in controlled conditions.

Scientists aboard the Australian icebreaker RSV Nuyina have collected a range of marine species during a 60-day expedition to the Denman Glacier in East Antarctica. The team is surveying the ocean floor at depths between 3,300 and 19,500 feet to study organisms adapted to extreme conditions.
Among the discoveries are sea stars the size of dinner plates, sea spiders with leg spans up to 20 inches, and sea pigs — gelatinous animals related to sea cucumbers that feed on organic debris known as “marine snow.” A sea butterfly, a small marine mollusc resembling a flying snail, laid eggs in an onboard aquarium, allowing researchers to observe its early development.

Sea Spiders and Flying Snails Found in Antarctic Depths

Sea spiders, which are arthropods distantly related to crabs, inhabit a wide range of marine environments, including deep-sea habitats up to 13,000 feet below the surface. Over 1,300 species are known, some with internal organs that extend into their legs.

Fragile specimens were collected using a “wet well” tank — a seawater system on the vessel designed to preserve deep-sea organisms during transport and observation.