A Japanese research team has rewritten the record book of deep-sea biology. While sampling the Kuril-Kamchatka Trench in the northwest Pacific, from Hokkaido University Unusual leathery black cocoons attached to rock samples were sampled at a depth of 6200 meters.according to Biology Letters The cocoons are leathery black capsules 3 millimeters across; they contain embryos of free-living flatworms (phylum Platyhelminthes), the report said. Researchers found that the embryos are bathed in nutrient-rich yolk, which provides the developing embryo with protection from the extreme stresses of the deep-sea environment. Hokkaido University said the discovery provides a new world record for this flatworm, the deepest known so far, and that living organisms with complex, relatively simple body structures are essentially the same and can continue to exist no matter how much pressure they endure in the deep sea.
Record-breaking discovery at 6,200 meters under the Pacific Ocean
As part of a study of the Kuril-Kamchatka Trench in the northwest Pacific, a Japanese research team discovered several bizarre, pitch-black “eggs” attached to rock fragments. According to published in Biology Lettersthese specimens were discovered at a depth of 6,200 meters (more than 20,000 feet). The discovery sets a new world record for the deepest known location of a free-living flatworm, as they were found at almost twice the depth of the previous record (3,232 metres).
What’s inside? The secret of black cocoon
Although these structures are about 3 millimeters in diameter, they are not actually eggs but leathery egg sacs called cocoons. when Dr. Keiichi Kakui, Hokkaido University When the cocoons were opened with a microscope, each cocoon produced a milky liquid (later identified as egg yolk) that leaked out. Each egg sac contains three to seven flatworm embryos, some of which already show signs of internal organ development, according to research archived by the institute. Royal Society Press.
Deep Sea Survival Blueprint
An unexpected finding of the study was that several species of flatworms exist in the deep reaches of the ocean, and that many members of the flatworm family have similar embryonic morphologies. Because their embryonic development does not require major changes, these organisms are able to migrate from shallow coastal waters to deep ocean areas over geological time. This is achieved by developing a “time capsule” around the eggs as they develop into adults, thus protecting them from the underwater pressure and harsh chemical environment of the abyss.Therefore, finding intact embryos at these depths is a priority for this research (because it is unpredictable). These findings therefore lay the foundation upon which more research can be conducted to understand how organisms with simple body structures were able to move from the world’s shallow coasts to the deepest parts of the oceans over geological time.
