MORPHOLOGY OF THE WHITE SHRIMP 

 PENAEUS SETIFERUS (LINNAEUS 1758) 



By Joseph H. Young, Department of Zoology, Tulane University 



Penaeus setiferus, the white shrimp of the Gulf 

 of Mexico, represents an important component 

 of the commercial shrimp catch throughout the 

 northern, western, and southern margins of that 

 body of water. With the rise in importance of 

 the commercial shrimp industry to the economy 

 of the Gulf States in the past two decades, in- 

 formation about the life history, morphology, 

 physiology, and behavior of the edible shrimps 

 has become necessary, and even critical, to the 

 continued well-being of the industry. 



We know very little about the diet of the pe- 

 naeid shrimps, how far they travel in search of 

 food and mates, or what constitute barriers to their 

 activities. Our knowledge of digestion, of nervous 

 and glandular control of the processes of molting, 

 reproduction, and coloration is limited for the 

 most part to distant relatives of the Penaeidae. 

 Despite numerous efforts (Miiller 1863; Kishin- 

 ouye 1900; Hudinaga 1935, 1942; Pearson 1939; 

 Johnson and Fielding 1956), the stages of the life 

 cycle of penaeids are not certainly known and 

 consequently we have very little exact ecological 

 information about the larvae. Opinions vary on 

 the life span of adult penaeid shrimps. Whether 

 the adult females reproduce once and then die at 

 the end of a year or reproduce more than once 

 a season, or again, live for 2 years and reproduce 

 each season is not known. The answers to such 

 questions will have a profound effect on the future 

 conduct of the commercial shrimp industry. 



This study sets forth in detail the anatomy of 

 Penaeus setiferus. Anatomical work as such does 

 not answer the problems suggested above, but as a 

 map to the explorer, anatomy provides the experi- 

 mental biologist with a guide to the ''lay of the 

 land." thereby facilitating his progress. And as 



Note. — Approved for publication April 22. 1958. Fishery 

 Bulletin 145. Report of research clone under contract between 

 Bureau of Commercial Fisheries and Tulane University (Salton- 

 stall-Kennedy Act). 



a map, the value of an anatomical study to its 

 users hinges upon its accuracy and clarity. To 

 these ends all efforts were bent, the illustrations 

 are large and the structures shaded to give a sense 

 of depth. The anatomical parts are labelled with 

 full words, rather than disguised with crypto- 

 graphic abbreviations listed below the illustra- 

 tions or hidden in the text. The plates are defined 

 as diagrams whereby important features may be 

 emphasized by artwork without sacrificing 

 accuracy. 



P. setiferus is an omnivorous scavenger dwell- 

 ing on or near mud-sand bottoms in the littoral 

 zone. The animal is probably restricted to the 

 euphotic stratum in which the light intensities are 

 fairly high. The shrimps are gregarious and 

 move about in large schools. The character of the 

 bottom is probably important to the white shrimp. 

 Evidence from various sources suggests that the 

 animals make use of mud or mud and sand by 

 burrowing into this soft substrate for protection 

 during molting and possibly for other purposes. 

 The white shrimp is a powerful swimmer and 

 capable of migrating great distances. These and 

 other aspects of the life habits of P. setiferus 

 have been considered in terms of functional 

 anatomy in the present study. 



Several people have made significant contribu- 

 tions to the progress of this study. Credit for 

 initiating the project belongs perhaps most of all 

 to Albert Collier, United States Fish and Wild- 

 life Service, Galveston, Tex. His unfailing coop- 

 eration, together with that of T. J. Costello of the 

 same laboratory, contributed greatly to the com- 

 pletion of the anatomical work. Help and en- 

 couragement has also come from Dr. Fred R. 

 Cagle, Dr. Royal D. Suttkus, and Dr. George H. 

 Penn, all of the Department of Zoology, Tulane 

 University. Percy Viosca, Louisiana Wildlife 

 and Fisheries Commission; Charles Dawson, of 



