Prawn, a marine decapod crustacean, of the macrourous division and genus palcemon (Fabr.). About 20 species are described, mostly small, though some from tropical regions are a foot long; they somewhat resemble the crawfishes in appearance, habits, and movements. The carapace is broad, prolonged anteriorly into an acute, laterally flattened rostrum, with eight or nine teeth above and three or four below, usually extending beyond the peduncles of the antennae; the eyes large and prominent; the first and second pairs of feet terminate in two-fingered claws, the second pair the largest and longest; carpus inarticulate; external jaw-feet short and slender; external antennae very long, with a scale at the base, and sometimes with three threads; five pairs of fin-like fringed feet under the tail, the principal swimming organs in forward locomotion; tail ending in movable leaflets as in the lobster, by which the animal darts rapidly backward when alarmed. The best known, most common, and most esteemed as food is the serrated prawn (P. serratus, Leach), found on the coasts of England and France, in rocky situations, and in still, clear water, living among the floating seaweeds; it is about 4 in. long, of a bright gray, spotted and lined with darker purplish gray; it turns red by boiling.
It is taken in traps resembling lobster pots, but smaller and with closer meshes, and in bag nets. The flesh is tender, sweet, nutritious, and easily digested; it is generally cooked in vinegar and salt; on account of the thinness of the shell the whole animal is eaten; large numbers are consumed, and the London market is supplied principally from the isle of Wight and the Hampshire coast; the females in spring, when with eggs, are most highly esteemed; they are also used as bait; they must be cooked very soon, as the flesh decomposes quickly, and with an almost insupportable odor. Very many are devoured by fishes, but their numbers are kept undiminished by their remarkable fecundity. They are rapid swimmers when alarmed. There are other species in the Mediterranean, the largest of which are salted, and are consumed by the Greeks and Armenians during Lent. The American prawn (P. 'vulgaris, Say) is much like the P. squilla (Fabr.) of Europe; it is a little larger than the shrimp, about 1 1/2 in. long, and may be known by the large, upturned, toothed rostrum; the fingers of the second pair of feet are shorter than the hand.
Serrated Prawn (Palaemon serratus).