Figure 10. — Pcnacus (L.) sctifcnis (L.). Posterior por- 

 tion of sternite XII and tonguelike lamella of sternite 

 XIII, 9 -15 mm. c.l., off Cocoa Beach, Fla. 



"green shrimiD." The entire body of this species 

 often has a bhiish hue that is due to a predomi- 

 nance of bhie chromatophores which are concen- 

 trated near the margms of the telson and uropods. 

 Intermingled with the bhie are red cliromato- 

 phores in the distal portion of uropods that form 

 a brownish-purjjle blotch ; the uropods also bear a 

 narrow yellowish marginal band. A dark band of 

 black specks occurs close and parallel to the pos- 

 terior margins of the carapace and the abdominal 

 somites. The sides of the body are often pinkish and 

 the pleopods as well as the tips of the pereopods 

 are dark red. 



Distribution and Morphological Variations 



Penaeus setiferus ranges along the Atlantic 

 Coast of the United States from Fire Island, N.Y. 

 (Burkenroad, 1934), to Saint Lucie Inlet in east 

 Florida (Gunter and Hall, 1963) ; its center of 

 abundance is in Georgia and northeast Florida 

 (Anderson and Lunz, 1965). Its range along the 

 coast of Florida is discontinuous; the species is 

 absent around the southernmost portion of the 

 peninsula and along the Gulf Coast to the mouth 

 of the Ochlockonee River in the west portion of 

 Apalachee Bay. The white shrimp appears again 

 in the mouth of the Ochlockonee River (Eldred, In 

 Joyce, 1965) and its range extends along the north 

 coast of the (Julf and the northeastern Mexican 

 Coast — with a center of abundance in Louisiana — 

 and contiiaues uninterrupted southward around 

 the Golfo de Campeche to the vicinity of Ciudad 

 Campeche — with another center of abundance in 

 northeast Tabasco and the adjacent waters of 

 Campeche. 



Bullis and Thompson (1965) took tliis species 

 at lat. 2(r IT' X., long. 91° 35' W., which is the 

 northernmost record on the Continental Shelf of 

 Yucatan and is proljaljly \ery close to the nortiiern 

 limit of its range along this Coast (fig. Ti). 



Figure 11. — Penaeus (L.) setiferus 

 44 mm., c.l., off Sabine River. Tex. 



(L.). Thelycum, ? 



The white shrimp also has been recorded three 

 times from near the Tortugas Islands. Springer 

 and Bullis (1952) found a single specimen north 

 of those islands in 25 fm. Boone (1930) described 

 and illustrated a male which she stated had been 

 taken in the Marquesas Keys in 30 fm. Thanks to 

 the cooperation of Woodhtxll B. Young, I had the 

 opportunity to examine PenacuH in the Vanderbilt 

 Museum, where the specimen recorded ijy Boone 

 was supposed to lla^•e been deposited, but I failed 

 to locate it. Finally, Kutkuhn (1962) reported 

 white shrimp from the Sanibel-Tortugas area on 

 the basis of a jirocessing plant's rejDort. Because 

 this species has not been found in the enormous 

 amount of material examined in the man}' inves- 

 tigations carried out in southwestern Florida, the 

 records of Boone and Kutkuhn may have been 

 erroneous. 



Formerlj-, white shrimp were believed to be 

 absent from south of Cabo Rojo, along the coast 

 of Veracruz to Tupilco, Tabasco. Recently, how- 

 ever, I examined a number of specimens from 

 Tnxpan, and a single male from Laguna de Buen 

 Pais, near Alvarado, Veracruz, so the species is 

 present along that coast even though it may be 

 scarce. 



P. setiferus has a more localized distribution 

 within its range than do the sympatric species of 

 Penaeus. Its range not only has a wide gap but also 

 has interruptions within restricted areas. A num- 

 ber of factors — salinity, temperature, substrate. 



WESTERN ATLANTIC SHRIMPS OF GENUS PENAEUS 



477 



