Deep-sea invertebrates are animals without a backbone that live in the ocean's depths, often at depths greater than 200 meters. These creatures include a variety of species such as jellyfish, octopuses, and sea cucumbers. They have adapted to extreme conditions, including high pressure, low temperatures, and complete darkness. Many deep-sea invertebrates possess unique features to survive in their environment. For example, some have bioluminescent abilities, allowing them to produce light for communication or attracting prey. Others have specialized feeding mechanisms to capture food in a nutrient-scarce habitat, showcasing the incredible diversity of life in the deep ocean.