A mussel is a type of shellfish that lives in both freshwater and saltwater environments. They have two hard shells, or valves, that protect their soft bodies inside. Mussels are often found attached to rocks or other surfaces in the water, using a strong thread-like substance called byssus. They are popular in many cuisines around the world, often cooked in dishes like moules marinières. Mussels are not only delicious but also nutritious. They are a good source of protein, vitamins, and minerals, making them a healthy choice for meals. Additionally, mussels play an important role in their ecosystems by filtering water, which helps maintain water quality in their habitats.