A hydrothermal vent is an opening in the ocean floor where heated water rich in minerals is released from beneath the Earth's crust. These vents are typically found along mid-ocean ridges, where tectonic plates are moving apart. The water can reach temperatures of over 400 degrees Celsius and is often rich in sulfur and other minerals. Hydrothermal vents support unique ecosystems that thrive in extreme conditions. Organisms such as tube worms, chemosynthetic bacteria, and various crustaceans rely on the chemicals released by the vents for energy, rather than sunlight. This makes them an important area of study for understanding life in extreme environments.