pond at the same season but with somewhat larger shrimp. Survival appeared 

 good and was comparable in marked and unmarked groups. In both series of 

 experiments individuals were recaptured by seining and trapping. At no time 

 were natural food supplies augmented artificially. In the latest experiment, 

 pond temperature ranged from 26" to 33° C. and salinity from 27%o to 36%o. 



Device for rapid measurement of small shrimp. Basic construction is 

 of plastic tubing. Note variously colored size- range calibrations. 



Penaeid species complex in south Florida waters Until recently, Penaeus 



duorarunn, the pink shrimp, was believed to be the only member of the genus 

 Penaeus occurring in south Florida waters. In I960 Florida State Board of 

 Conservation scientists detected small numbers of P. brasiliensis in samples 

 of shrimp taken from Biscayne Bay, and the Bureau of Commercial Fisheries 

 exploratory vessel SILVER BAY took large P. aztecus (brown shrimp) from 

 50-60 fathoms southwest of the Matecumbe Keys. Since these coexistent spe- 

 cies are practically indistinguishable at all but the most advanced stages, the 

 question arose as to what degree such a complex might invalidate the results 

 of research directed toward pink shrimp per se. 



To answer this question, systematic samples of commercial shrimp 

 catches are being taken at various points along the south Florida coast to as- 

 certain, insofar as possible, the seasonal occurrence and distribution of each 

 species. Examination of samples from Biscayne Bay and Hawk Channel are 

 revealing small percentages of P. brasiliensis in catches dominated by pink 

 shrimp. A form resembling P. aztecus has been found in a few of the Bis- 

 cayne Bay samples. Samples from the southwest Florida coast area (Pine 

 Island Sound) have thus far indicated the presence of P. duorarum exclusively. 



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