Milne-Edwards, 1837
Description
Rostrum straight or very slightly upcurved, projecting beyond tip of scaphocerite; tip occasionally bifid; seven or eight dorsal teeth, three or four ventral teeth (rarely five). Two of the dorsal teeth behind the posterior edge of the orbit, the second tooth about 1.5 x more distant from the first than from the next distally.
Carapace with antennal and branchiostegal spines. Antennules triramous, the shorter ramus of the outer flagellum about 0.66 x length of the peduncle and fused for about a third of its length to the longer ramus. Outer border of stylocerite straight or slightly convex, anterior border convex.
Scaphocerite extends to distal half of carpus of pereiopod 2, occasionally little further; apical spine not exceeding lamellar portion. Maxilliped 3 with exopod.
Mandible with molar and incisor process, and three-segmented palp. Dactyl of pereiopod 2 about 0.4-0.5 x length of propus, but variable; dactyl and carpus slender; carpus equal to or very slightly longer than merus.
Telson with two pairs of lateral spines.
Remarks
Unlike Palaemon elegans, this species turns an opaque white when dead and before fixation; therefore, it has been given the name "white shrimp".
Size
Length up to 77 mm.
Colour
Usually almost colourless. When viewed closely bands of blue-grey pigment are noticeable on the carapace and pleonites, plus some orange spots between the bands.
Ecology
Occurs in the upper reaches of large estuaries, often in dense shoals.
Ovigerous females occur from April-May to August. The complete larval development has been described by Fincham (1979b).
Depth range
A shallow water species.
Distribution in the North Sea
All North Sea.
World distribution
Ranges from coasts of Britain and NW Germany southwards into the Mediterranean.
[mainly after Smaldon, 1993]