9 facts
They are the longest-living vertebrate on Earth, reaching sexual maturity around 150 years old. Their incredibly slow metabolism and cold, deep-sea habitat contribute to their extreme longevity, allowing them to witness centuries of history.
This "unihemispheric slow-wave sleep" allows them to remain vigilant for predators and surface for air while resting. Their active brain half ensures they don't drown or become vulnerable, demonstrating remarkable evolutionary adaptation.
Through radiocarbon dating of their eye lenses, scientists discovered these Arctic predators have an average lifespan of 272 years, with some individuals estimated to be 500 years old. They grow only about a centimeter per year, contributing to their longevity.
Two hearts pump blood through the gills, while the third circulates it to the rest of the body. This unique circulatory system helps them thrive in low-oxygen deep-sea environments and efficiently deliver oxygen to their muscles.
This makes it the longest-living vertebrate known to science, far surpassing any other species. It grows extremely slowly, only about 1 cm per year, and reaches sexual maturity around 150 years old in the frigid waters of the North Atlantic.
Instead of bones, sharks have skeletons made entirely of cartilage, a flexible and durable connective tissue. This makes them lighter and more agile in the water, contributing to their impressive predatory abilities.
Two pump blood through the gills, while the third circulates blood to the rest of the body. This unique circulatory system allows them to thrive in oxygen-poor deep-sea environments, making them incredibly efficient marine predators.
Unlike most animals, octopuses frequently edit their RNA molecules, allowing them to fine-tune protein functions and adapt to environmental changes in real-time. This remarkable ability bypasses slower genetic mutation processes, contributing to their unique intelligence and survival.
Two hearts pump blood through the gills, while a third circulates it to the rest of the body. Their copper-based hemocyanin gives their blood a distinctive blue hue, unlike the iron-based hemoglobin in human blood.