White shrimp - Litopenaeus setiferus

 

white shrimp

Diagnostic characters: Carapace smooth. Rostrum armed with usually 7 to 9 teeth on dorsal margin, and 2 teeth on ventral, its tip long and slender (almost half the length of rostrum);adrostral sulcus and carina short, not exceeding anterior half of carapace; gastrofrontal carina absent; postrostral carina well defined anteriorly, faint posteriorly, its median sulcus short and shallow. Dorsolateral sulcus on last abdominal segment very faint and without lips. Antennae long, 2.5 to 3 times the body length. Distal portion of lateral lobes of petasma bearing a conspicuous diagonal rib on inner surface. Thelycum without lateral plates, but with 2 curved ribs on anterior portion of sternite 14 converging toward the midline but not uniting; ribs followed posteriorly by a pair of fleshy subelliptical lobes. Colour: usually a translucent bluish white, sometimes greyish or greenish, with rostrum and sides pinkish; dark grey transverse lines running parallel to posterior margin of carapace and on abdominal segments; pleopods reddish, telson and uropods with a red/blue band near their margins; the uropods also bear a brownish purple distal blotch and a narrow, yellowish marginal band. Juveniles are light grey, often with a greenish tinge, with bluish specks scattered over the body and densely concentrated on spines and crests; the uropods have a brown or reddish brown distal blotch.

Size: Maximum total length: females, 257 mm; males, 175 mm.

 Habitat, biology, and fisheries: Normally inhabits estuaries and inner oceanic littoral, being more abundant at depths less than 30 m; it may, however, occur in deeper waters (to 82 m). The largest concentrations are found in extensive brackish water areas of softmud or clay bottoms (sometimes with sand) connected with the sea.The postlarvae and juveniles grow up in estuarine waters, especially on vegetatedmud bottoms rich in organic debris. An omnivorous species, although it prefers certain types of food such as polychaete worms. Centres of abundance are off Georgia and northeast Florida, Louisiana, Tabasco, and Campeche. This species is of great economic importance in the USA and Mexico. Fishing operations at sea extend to depths of about 27 m.A sizeable fishery of juveniles occurs in estuarinewaters, although its yield is considerably smaller than that of the marine fishery for adults. In the fisheries statistics for the years 1984 to 1998 Litopenaeus setiferus was referred as Penaeus setiferus.From 1984 to 1998 the capture production reported from the USA totaled 572 349 t (mean capture production was 38 156 t/year). This species accounts for part of the Mexican shrimp catches, which totaled 540 864 t in the Area 31. In Mexico the penaeid catches are not broken down to species; instead, species are combined and referred as Penaeus spp. Adults are mainly caught with American- type shrimp trawls (balloon and flat); usually 2 trawls are towed simultaneously (double-rig).Juveniles and subadults are taken in inshore and near shore waters with different types of gear: seines, push nets, dip nets, cast nets, lift nets, drop nets, frame trawls, and side frame trawls. This species is marketed mostly frozen and canned, and exported all over the world. Juveniles and subadults are often sold as live bait. This species has been farm-raised on a small scale.

 Distribution: New York (Fire Island) to Florida (Saint Lucie Inlet); near Dry Tortugas (rarely); Gulf of Mexico from Ochlocknee River, Florida, to Campeche, Mexico.