356 U. S. BUREAU OF FISHERIES 



the sea-bob, Xiphopenaev^s hroyeri,. The common shrimp is by far 

 the most important because it comprises at least 95 percent of the 

 commercial catch. 



From a commercial standpoint, the shrimp fishery is in better con- 

 dition than it has been in the last few years. Indications are that the 

 pack of canned shrimp during the 1934—35 season will be larger than 

 in the past several years with the market price holding up well. A 

 closer organization of the canners and more cooperation between them 

 was noted during 1934. The inauguration of the inspection system 

 under the Pure Food and Drug Administration and the work of the 

 shrimp section of the National Canners Association have resulted in 

 a much improved pack of shrimp. The increase in the pack probably 

 will cause a similar augmentation in the total landings of shrimp. 



Because of the importance of the common shrimp, the major efforts 

 of the investigation have been directed toward solving the problems 

 presented by this species. The length measurements and gonad exami- 

 nations show that the common shrimp reach maturity and spawn 

 within 1 year. Not many spent shrimp are found and no shrimp 

 which can be interpreted as being 2 or more years old has been taken. 

 It is assumed from this that the shrimp die after spawning and that 

 A'ery few, if any, survive to spawn the following year. The spawn- 

 ing of the common shrimp occurs throughout the spring and summer 

 in the open sea or Gulf, and the shrimp after hatching and passing 

 through the larval stages move into the inside waters. These warm 

 shallow sounds, bays, bayous, and rivers serve as nursery grounds. 

 The young shrimp grow very rapidly and by June or July, depend- 

 ing upon the locality, attain sufficient size to ap])ear in the commercial 

 catch. By September almost the entire catch is com]:)osed of young 

 shrimp from the spawning of the preceding spring and early summer. 

 With the cooling of the waters in the early fall and winter there is a 

 definite disappearance of the larger of the young shrimp from the 

 inside waters and in some sections of the coast from the customary 

 outside fishing grounds which, with few exceptions, are usuall}^ near 

 the mouths of the passes. 



At Beaufort, N. C, Dr. J. S. Gutsell has continued his studies of 

 the structure and development of the ovarian eggs of the commercial 

 species of shrimp. This study is of importance in determining just 

 when spawning occurs and if a shrimp spawns more than once. Sec- 

 tions of many ovaries, including a number from the common shrimp 

 with spermatophores attached, have been microscopically examined. 



Because so few of the common shi'imp are taken with sjoermato- 

 phores attached and because of the method of attachment, it seems 

 certain that the sj)ermatophores are not present on the female until 

 they are ready or very nearly ready to spawn. Therefore, the large 

 eggs found in the enlarged ovaries of all shrimp of this species with 

 spermatophores attached are believed to be not only fully developed 

 but also in a mature condition ready for emission and fertilization. 

 Examination of such mature eggs reveals certain definite and distinc- 

 tive structures in the yolk. These are not artifacts for under favor- 

 able conditions they may be seen in fresh eggs immediately after re- 

 moval from newly killed shrimp. By proper fixation and staining 

 they may be preserved and studied in sections which afford a superior 

 picture of conditions within the ovary. One type of cytoplasmic body 



