Crangon crangon is a species of caridean shrimp found across the northeastern Atlantic Ocean from the White Sea in the north of Russia to the coast of Morocco, including the Baltic Sea, as well as occurring throughout the Mediterranean and Black Seas. It is commercially important and fished mainly in the southern North Sea. Its common names include brown shrimp, common shrimp, bay shrimp, and sand shrimp, while translation of its French name (or its Dutch equivalent ) sometimes leads to the English version grey shrimp. Description Adults are typically long, although individuals up to have been recorded. The animals have cryptic colouration, being a sandy brown colour, which can be changed to match the environment. They live in shallow water, which can also be slightly brackish, and feed nocturnally. During the day, they remain buried in the sand to escape predatory birds and fish, with only their antennae protruding. Crangon is classified in the family Crangonidae, and shares the family's characteristic subchelate first pereiopods (where the movable finger closes onto a short projection, rather than a similarly sized fixed finger) and short rostrum. Distribution and ecology C. crangon has a wide range, extending across the northeastern Atlantic Ocean from the White Sea in the north of Russia to the coast of Morocco, including the Baltic Sea, as well as occurring throughout the Mediterranean and Black Seas. Despite its wide range, however, little gene flow occurs across certain natural barriers, such as the Strait of Gibraltar or the Bosphorus. The populations in the western Mediterranean Sea are thought to be the oldest, with the species' spread across the north Atlantic thought to postdate the Pleistocene. Adults live epibenthically (on or near the sea-floor) especially in the shallow waters of estuaries or near the coast. It is generally highly abundant, and has a significant effect on the ecosystems where it lives. Lifecycle Females reach sexual maturity at a length around , while males are mature at . The young hatch from their eggs into planktonic larvae. These pass through five moults before reaching the postlarval stage, when they settle to the sea-floor. Fishery Historically, the commercial fishery was accomplished by horse-drawn beam trawls on both sides of the Dover straits. In the sandy shallows of Morecambe Bay (Lancashire, UK) horses have been replaced by tractors. Some small fishing vessels also use beam trawls for brown shrimp. A few artisanal fishermen use