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BODY STRUCTURE OF SHRIMP

The body of shrimp has 2 main parts: the cephalothorax (head and thorax fused together) and the abdomen. The cephalothorax is immovable, elongated in the case of shrimp, covered with a carapace (carapax). The carapace also covers gills. It bears elements used for scientific classification: the rostrum ('beak') and two pairs of antennea (the first pair are called antennules). Antennea are used as sensory organs. Shrimp have compound eyes placed on eye stalks in front of the head. The cephalothorax holds 5 pairs of pereiopods (walking legs). Together this gives shrimp 10 legs, thus the order name 'decapoda', meaning 'ten-legged'. The first pair of pereiopods are called chelipeds, they have claws and usually are used for picking up food. The rest of the pereiopods are called paraeopods and are used for walking. They also bear sexual organs of the shrimp. In front of the walking legs are 6 pairs of mouthparts: a pair of mandibles, 2 pairs of maxillae and 3 pairs of maxillipeds. Maxillipeds are used for moving water in order to enrich it in oxygen and partly as gills.

The abdomen is movable, it moves from back to front. It is built of 6 parts (segments). First 5 segments bear limbs called pleopods or swimmerets (commonly called swimming legs), the last segment is called the telson. Together with a pair of uropods it forms a tail fan. The tail fan is used for steering during swimming. The shrimp's anus is under the telson. Shrimp use pleopods for swimming. Female shrimp use them for brooding eggs. In case of males, the first pair of pleopods is used for fertilization.

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