Hirondellea gigas is a species of amphipod crustacean found in the hadal zone of the Pacific Ocean, particularly in the Mariana Trench. It is adapted to extreme deep-sea environments, living at depths exceeding 10,000 meters where pressures are immense and temperatures are near freezing. This species feeds on organic matter that sinks to the ocean floor, playing a crucial role in the deep-sea ecosystem as a scavenger. Its unique adaptations, such as a lightweight exoskeleton and specialized enzymes, allow it to survive and thrive in one of the most extreme habitats on Earth.