An elegant creature is the common prawn, or rock-shrimp, as the fishermen designate him, by way of distinction from another sapid crustacean that inhabits these shores. His armour of proof, composed of plates that slide so smoothly one under another, sustains the most lustrous polish, and is ever subject to the animal’s efforts to keep it so; for, whenever he has a moment’s leisure from more pressing avocations, he is constantly engaged in cleaning it with the brushes which those slender fore-limbs of his carry. Like a true soldier, like a knight of chivalry, the Prawn lives, eats, sleeps in armour. How completely is his body encased in defensive mail; and he carries his tempered weapon too. Look at the serrate sword which he always points at the foe whom he faces! Who would rashly provoke such a weapon as this? Stiff and firm in substance, long, pointed, two-edged, keen on both edges, curved sabre-like, and cut into acute teeth; it does seem a most formidable affair: and yet, truth to tell, I do not know what use the owner makes of it. Though I have been for many years in the practice of keeping these elegant animals in my aquaria, I have never seen one smite a foe with his two-edged sword. Perhaps like the cane over the looking-glass in a nursery, its mere presence is sufficient to keep in awe encroaching enemies, whose hearts sink when they behold the sharp-toothed weapon.
Exquisitely painted is the Prawn. His ground colour is semi-pellucid olive-grey, on which transverse lines of black are drawn; and specks and dashes of sparkling white, symmetrically arranged and well defined, are scattered here and there, especially upon the broad swimming plates that serve as his principal instruments of locomotion. His limbs, too, are ringed with blue and orange, a felicitous combination!
I have just alluded to the tail as a motive power. It is a very curious organ, consisting of five plates, so hinged that they can play over each other, or be spread out in shape of a fan, and each plate beset on its edges with a most delicate fringe of stiff bristles. To see its use, you have only to approach the animal. He instantly darts away with force; all the while, however, keeping his face to the foe, as becomes a soldier so armed. Now this retrocessive power is his great _cheval de bataille_. When gently exploring, he crawls among the weeds on the tips of his long feet; when swimming at ease, he glides gracefully along by the rapid paddling of the false feet, of which he carries five pairs beneath his abdomen. But when alarmed, he forcibly throws forward this plated tail, expanded to the utmost, bending the last joints of the body from the hump on his back, and thus strikes a powerful forward blow on the water, by the impact of which the whole prawn is jerked backward to a distance of several inches.