358 t'. S. BUREAU OF FISHERIES 



Kenneth H. Mosher continued sampling the conmiercial catch of 

 shrimp at Aransas Pass through tlie calenchir year 1934. In 1933 the 

 sampling was extended to include the commercial catch at four other 

 Texas ports — Galveston, Palacios, Port Lavaca, and Port Isabel. 

 The shrimp fishing at Palacios, Port Lavaca, and Port Isabel was so 

 irregular that these three ports were disregarded in 1934, leaving 

 only Aransas Pass and Galv^.stou as regular sampling localities. 

 During 1934, 20,516 shrimp were sexed, measured, and sexual matur- 

 ity noted. Only 145 of the total measured were P. hrasiliensis and 

 only 71 were Xlphopenaeus hroyerl^ or the two species taken together 

 were only slightly over 1 percent of the total yearly sample. The 

 remaining 20,300 shrimp were P. setlferus. In addition to the routine 

 sampling, a innnber of the shrimp were weighed as well as measured 

 in order to obtain the weight-length relationship. 



After many unsuccessful attempts to keep shrimp alive for any 

 length of time in various types of live boxes and aquaria, two pens 

 were devised and placed in a small pond separated from Redfish Bay 

 by a dike in which screened sluiceways were built to provide a cur- 

 rent of Avater to the pond. 



Early in December Mr. Lindner and Mr. Mosher initiated tagging 

 experiments upon some shrimp placed in the pens. The celluloid 

 disk or button tag was used. Although inclement weather caused 

 the death of the shrimp a few weeks after tagging, the residts were 

 encouraging as it was evident that the shrimp were able to withstand 

 the rigors of handling while being tagged. Mr. Mosher will continue 

 these experiments as soon as the danger of freezing has passed. 



Studies on the spawning and early growth of the commercial 

 peneid shrimps have been continued by John C. Pearson. A unique 

 discovery during the year was the recognition of the eggs of a peneid 

 shrimp, pi'obably Penaeus setlferus. These eggs, taken off the coast 

 of Georgia on June IT, 1932, in surface plankton, appear to be the 

 first peneid shrimp eggs to be secured in a pelagic state. The eggs 

 were spherical in shape and possessed an extremely thin delicate 

 membrane. The diameter of the eggs ranged from 0.38 to 0.42 milli- 

 meter. Within each otherwise transparent e^<r rested a well-devel- 

 oped nauplius, the length of which ranged from 0.21 to 0.26 

 millimeter. The capture of these eggs at the surface in water of 

 30-foot depth would indicate that the eggs were spawned relatively 

 close inshore and that they are strictly pelagic, floating at the surface 

 of the sea. 



Nauplii, zoae, and mysis stages of the connnercial peneid shrimps 

 have been abundantly secured in many plankton collections off the 

 coasts of Louisiana, South Carolina, Georgia, and Florida. Zoae and 

 mysis stages of both the commercial shrimps, Penaeus setlferus and 

 P. hrasilie?isis, are at hand and are being studied in detail with re- 

 spect to morphological distinctions and oceanic distribution as to 

 time and place. It is hoped that a report on the morphology and 

 distribution of the young of these commercial shrimps can be com- 

 pleted during the coming year. Considerable material on the young 

 stages of various noncommercial shrimps has also been collected with 

 the studies of the connnercial shrimps. 



