Crangon crangon

The brown shrimp, known scientifically as *Crangon crangon*, is a species of caridean shrimp. It is a highly abundant creature found across the northeastern Atlantic Ocean. This species is commercially important to many human fishing industries. It plays a significant role in the ecosystems where it lives. Scientists classify these shrimp within the family Crangonidae. They are known by many names, including common shrimp, bay shrimp, and sand shrimp.

These shrimp have unique physical features that help them survive. They possess subchelate first pereiopods, which are specialized limbs. In these limbs, a movable finger closes against a short projection. They also have a short rostrum, which is a pointed part of their head. To stay safe, they use cryptic coloration. This means they have a sandy brown color that helps them hide. They can even change this color to match their specific environment.

The lifestyle of *Crangon crangon* is shaped by the day and night. They are nocturnal, which means they primarily feed during the night. During the daylight hours, they seek safety by burying themselves in the sand. This behavior protects them from predatory fish and birds. While buried, they leave only their long antennae protruding from the seabed. They typically live in shallow waters. These areas can sometimes be slightly brackish, meaning they contain a mix of fresh and salt water.

The life cycle of the shrimp involves several distinct stages. Females reach sexual maturity at a length of approximately 30 millimeters. Males reach maturity at a slightly smaller length of about 25 millimeters. After eggs are laid, they hatch into planktonic larvae. These tiny larvae float freely in the water column. The larvae must undergo five moults, which are periods of shedding their shells. After these five stages, they reach the postlarval stage and settle onto the sea floor.

*Crangon crangon* has a very wide geographic distribution. Their range extends from the White Sea in northern Russia to the coast of Morocco. They are also found in the Baltic, Mediterranean, and Black Seas. Despite this range, natural barriers limit their movement. For example, the Strait of Gibraltar and the Bosphorus prevent much gene flow between populations. Some scientists believe the populations in the western Mediterranean are the oldest. They think the species spread across the north Atlantic after the Pleistocene period.

Humans have developed many ways to catch these shrimp for food. Historically, fishermen used horse-drawn beam trawls near the Dover straits. In Morecambe Bay, England, tractors have replaced horses to pull these nets. In 1999, the global catch exceeded 100,000 tonnes. Germany and the Netherlands were responsible for over 80% of that amount. In the UK, annual landings average about 1,000 tonnes. However, this number varies greatly, ranging from 500 to 1,500 tonnes.

Predicting shrimp catches involves looking at complex environmental patterns. In Lancashire, landings are linked to air temperature and previous year rainfall. Interestingly, shrimp abundance in Lytham also correlates with the Zürich sunspot number. This means the number of sunspots on the sun can help predict catches. Scientists observed this connection during the period from 1965 to 1975. Sunspot Cycle No. 23, from 1997 to 2008, also showed this correlation.

Brown shrimp are a popular food item in several European countries. They are commonly eaten in Belgium, the Netherlands, northern Germany, and Denmark. In Belgium, they are used in the dish *tomate-crevettes*. This dish mixes shrimp with mayonnaise and parsley inside a hollow tomato. Another specialty is the shrimp croquette, which uses béchamel sauce. In England, people make potted shrimps using butter and spices like nutmeg. However, Greenpeace Germany labels them an unsustainable choice due to microplastics found in them.