gas-liquid chromatographic analysis (see footnote 

 4). 



Ac know Icclgments 



We thank the following laboratories for helping 

 to establish the validity of these methods by par- 

 ticipating in verification studies: Seattle, Detroit, 

 and New Orleans District Laboratories of the U.S. 

 Food and Drug Administration; the Gulf Breeze, 

 Fla., Field Station of the Environmental Protec- 

 tion Agency; the Wisconsin Alumni Research 

 Fund Institute, Madison, Wis.; and the Iowa De- 

 partment of Agriculture, State Chemical Labora- 

 tory, Des Moines. 



Robert Reinert willingly shared his methods 

 with us before they were published. Daniel B. 

 Menzel, formerly of the Institute of Marine Re- 

 sources, University of California, Berkeley, Calif., 

 generously shared his knowledge of the intricacies 

 of chlorinated hydrocarbon analysis. Laura G. 

 Lewis provided technical support in developing 

 this procedure. 



Literature Cited 



Horowitz, W. (editor). 



1970. Fat-containing foods. /n Official methods of analysis 

 of the Association of Official Analytical Chemists. 11th 

 ed., p. 480. Assoc. OfT. Anal. Chem., Wash., D.C. 



Pksticide Analytical Manual. 



1977. Gas-liquid chromatography. In Pesticide analytical 

 manual. Vol. I, Chapter 3. U.S. Dep. Health, Educ, and 

 Welfare, Food and Drug Admin., Wash., D.C. 

 PORTKR, M. L., S. J. V. Young, and J. A. Burke 



1970. A method for the analysis offish, animal, and poul- 

 try tissue for chlorinated pesticide residues. J. Assoc. Off. 

 Anal. Chem. 53:1300-1303. 



Reinert. R. e. 



1970. Pesticide concentrations in Great Lakes fish. Pestic. 

 Monit. J. 3:233-240. 



Snyder. D., and R. reinert 



1971. Rapid separation of polychlorinated biphenyls from 

 DDT and its analogues on silica gel. Bull. Environ. Con- 

 tam. Toxicol. 6:385-390. 



Virginia F. Stout 



Northwest and Alaska Fisheries Center 

 National Marine Fisheries Service, NOAA 

 2725 Mont lake Boulevard East 

 Seattle. WA 98112 



F. Lee Beezhold 



Northwest and Alaska Fisheries Center 



Present address: Food Chemical and Research Laboratories. Inc. 



4900-9th N.W., Seattle, WA 98107 



GROWTH OF JUVENILE SPOT PRAWN, 



PANDALUS PLATYCEROS, IN 



THE LABORATORY AND IN NET PENS 



USING DIFFERENT DIETS 



Floating net pens have been used to culture Pacific 

 salmon, genus Oncorhynchu.'^. in the marine wa- 

 ters of the West Coast since 1969 ( Mahnken 1975). 

 Although it has been a monoculture effort to date, 

 use of a companion crop species such as the spot 

 prawn, Pandalus platyceros Brandt, could diver- 

 sify and enhance this industry. 



In 1975 the National Marine Fisheries Service 

 selected the spot prawn to examine as a potential 

 companion species to net pen-reared salmon. The 

 spot prawn was selected as a candidate for several 

 reasons; 1 ) it has a rapid growth rate and large size 

 compared with other pandalids (Butler 1964); 2) it 

 can be successfully cultured to maturity in captiv- 

 ity (Prentice 1975); 3) it will reproduce in captiv- 

 ity, often for two consecutive years (Rensel and 

 Prentice 1977); 4) it is gregarious and is normally 

 not cannibalistic; 5) it adapts to vertical or hori- 

 zontal substrates; and 6) it scavenges for, and ac- 

 cepts, a wide variety of foods (Wickins 1972). 



Coincident to investigating the prawn as a com- 

 panion crop to salmon, several prawn diets were 

 evaluated with prawns held in tanks and net pens 

 at the NMFS Aquaculture Experiment Station on 

 Puget Sound near Manchester, Wash. These ex- 

 periments wer^ conducted using diets made up of 

 underutilized marine species or fishery byprod- 

 ucts that are available to most salmon farmers. 



Materials and Methods 



The spot prawns used in the experiments were 

 laboratory-reared progeny of females captured in 

 Hood Canal, Wash. Three concurrent experiments 

 with juvenile prawns ( <1 yr of age) began 10 July 

 1975 (Table 1). 



Experiment A was conducted in the laboratory 

 where prawns were held in flowing seawater tanks 

 at 110 animals/m^ of immersed substrate. Four 

 diets were evaluated: 1) steamed mussel, Mytilus 

 ediilis. meat; 2) chopped salmon that had died in 

 nearby net pens; 3) feces and pseudofeces from the 

 Pacific oyster, Ci-assostrea iii^as (eight oysters per 

 replicate having a mean weight (total) of 153 g); 

 and 4) no food (control). Diets 1 and 2 were fed 

 every other day while diet 3 was always present in 

 varying amounts. A sample of 10 prawns for each 

 of four replicates was measured during each of 



886 



fishery BULLETIN: VOL 76, NO, 4, 1979. 



