Living beings in the deep sea have eyes because they need to be able to detect and respond to their environment. Even in the deep sea, there is some ambient light from bioluminescent organisms and other sources, so having eyes allows these organisms to detect prey, predators, and potential mates. Additionally, eyes can also help deep-sea organisms navigate and find their way in the dark, three-dimensional environment of the deep ocean. Overall, having eyes provides a survival advantage for deep-sea organisms by allowing them to interact with their surroundings and other organisms in their environment. **

Living fossils in deep-sea islands and jungle areas are species of plants or animals that have remained virtually unchanged for millions of years. These species are often considered living relics of ancient times, as they have survived major environmental changes and evolutionary pressures. In deep-sea islands, living fossils can include ancient species of fish, mollusks, and other marine organisms, while in jungle areas, they can be ancient plant species or primitive reptiles and amphibians. These living fossils provide valuable insights into the evolutionary history of life on Earth and the ways in which species have adapted to their environments over time. **

Deep-sea fish species are fish that live in the deep ocean, typically at depths of 200 meters or more. These species have adapted to survive in the extreme conditions of the deep sea, including cold temperatures, high pressure, and low light levels. Some examples of deep-sea fish species include anglerfish, gulper eels, lanternfish, and viperfish. These fish often have unique adaptations such as bioluminescence, large mouths, and elongated bodies to help them survive in their deep-sea environment. **

Deep-sea diving is a type of underwater diving that involves exploring the depths of the ocean, typically beyond depths reachable by conventional scuba diving. It requires specialized equipment, such as deep-sea diving suits, helmets, and breathing apparatus, to withstand the high pressure and cold temperatures found at these extreme depths. Deep-sea divers often conduct research, salvage operations, or exploration of underwater habitats in these challenging environments. **

Deep-sea anglerfish primarily eat small fish, crustaceans, and other invertebrates. They use their bioluminescent lure to attract prey in the dark depths of the ocean. **

The deep sea typically begins at depths of around 200 meters (656 feet) and extends down to the ocean floor, which can reach depths of over 11,000 meters (36,000 feet) in places like the Mariana Trench. **

The deep sea is home to a wide variety of unique and fascinating creatures, including anglerfish, gulper eels, giant squid, and deep-sea jellyfish. Many of these organisms have adapted to survive in extreme conditions of high pressure, darkness, and cold temperatures. Some deep-sea creatures have bioluminescent features to help them navigate and communicate in the dark depths of the ocean. Overall, the deep sea is a mysterious and diverse ecosystem that is still being explored and studied by scientists. **

Deep-sea diving mixtures are specialized gas mixtures used by divers to breathe at extreme depths. These mixtures typically contain a combination of gases such as helium, oxygen, and nitrogen in specific ratios to prevent conditions like nitrogen narcosis and oxygen toxicity. By using these mixtures, divers can safely explore deeper underwater environments for longer periods of time. The composition of the mixture is carefully calculated based on the depth of the dive and the physiological effects of the gases on the diver's body. **