ShrimpsCaridea

Caridean shrimps are marine crustaceans, typically 1-8 cm (0.4-3.1 in) in body length. They have a slender, somewhat laterally compressed body, equipped with two pairs of antennae and prominent stalked eyes. A distinguishing feature is the pleuron of the second abdominal segment, which consistently overlaps both the first and third. Many species are translucent or cryptically patterned; others exhibit bright red, white, or blue patterns. The prominent rostrum is often toothed, and the first two or three of their five pairs of walking legs (pereiopods) are typically chelate, bearing small pincers for feeding and defense.

These shrimps inhabit marine environments from shallow reef crests to at least 50 m (165 ft) on fore-reef slopes. They are found among coral branches, in rocky crevices, on sandy bottoms, and in seagrass beds. Many are free-living, primarily acting as scavengers and detritivores, consuming algae, plankton, and small invertebrates. Other species form symbiotic associations; cleaner shrimps remove parasites and dead tissue from fish at prominent cleaning stations. Additional species live commensally with anemones, corals, or gobies, where they gain protection. Many caridean shrimps are nocturnal.