The common shrimp (Crangon crangon) is a decapod crustacean like the prawn and the lobster…

Description
The common shrimp is small in size usually reaching a length of 5 to 6 cm. Its possesses a transparent compressed body. It is grey or brown in colour which makes it difficult to see in the water over the sandy bottom and it also has the capacity to change colour. Like other crustaceans the common shrimp has a body divided into three segments (tagmata); the first two which make up the carapace are the head (cephalon) and the thorax (pereion). They are joined to form the cephlothorax. The last segment makes up the abdomen (or pleon) and tapers to a fanlike caudal which is darker in colour. The head possesses two compound eyes which are set very closely together, antennae, a short rostrum and mandibles for grinding up prey. The thorax has five pairs of appendages (pereopods) which help it crawl and feed, the abdomen also possesses five pairs of appendages (pleopods) used for locomotion in particular.

Nutrition
The common shrimp is omnivorous; it hunts mainly at night and feeds on algae, planktonic animalcules, marine worms and other small sized animals and even dead animals.

Reproduction
This small crustacean is hermaphrodite: first of all male for one or two years, then it becomes female. Whatever the sex it possesses two gonads. The female lays from 2.000 to 10.000 eggs which are carried attached to the abdomen during incubation which lasts from one to two weeks. After hatching the larvae mix with the many species which form plankton. The common shrimp whose carapace does not grow, develops in stages (moulting).

Habitat and Behaviour
The common shrimp is a species found in the mud and sand of coastal areas in the tidal zone to 20 m (rarely more), in lagoons and the briny waters of estuaries. Its activity is linked to daylight and the tides. At low tide it burrows into the sand near the low tide mark.

Shrimping
The best way of catching shrimps is to push a shrimping net parallel to the shore scraping along the bottom. Two sorts of shrimping nets are commonly used; a semi-circular net or a large triangular net. The best time to go shrimping is at low tide or at the beginning of the incoming tide.
Photos © Sea-River