in this study have been previously documented (7). Gravid fish were collected 

 from Bissel Cove, Narragansett Bay (R.I.) and transported in aerated containers 

 to holding tanks located at the Environmental Protection Agency Laboratory, 

 Narragansett, R.I. Eggs were stripped from females onto nylon monofilament 

 screens with a mesh size of 400ju, and fertilized by bathing them in the milt of 

 two to three males (5). They were then suspended in egg hatching jars, 1 5 cm 

 in diameter, modified from the original design of Buss (12) by the addition of a 

 bottom center drain. 



After hatching, the fish were transferred to a 720 liter holding tank and fed 

 live 3-day -old brine shrimp. Fish were periodically removed during the two 

 month batch culture study for biochemical analyses. Fish used in both the 

 preliminary and expanded diet evaluations were cultured for approximately 

 two weeks. The jars used for hatching of the eggs, were also used as the culture 

 vessels in the artificial diet studies. For the eight-diet expanded study each jar 

 was stocked with 50, 23-day-old fish (individual mean weights, 8.90 mg) 

 obtained from the batch culture population; Two replicates were run for each 

 diet fed group. 



Diets and Feeding Procedures 



The wild plankton (Diet 1) were collected from a number of locations in the 

 west passage of Narragansett Bay, R.I. and from local estuarine areas with a 

 243/i mesh conical plankton net (Table 15-1). The plankton population was 

 comprised of a mixture of copepods, primarily Acartia tonsa, and some 

 invertebrate larvae (22). The plankton samples were transported to the 

 laboratory in insulated containers and held at 20'^C. 



The live brine shrimp nauplii (Diet 2) (San Francisco Bay Brand, USA) were 

 incubated for 24 hours in two liter separatory funnels containing filtered 



seawater (29.0 to 31.0 o/oo salinity, 20 to 22°C) and harvested after 72 hours. 

 A starved group served as a control (Diet 3). The freeze-dried brine shrimp 

 (Diet 4) was obtained by freezing the live brine shrimp to -38°C and then 

 drying at 4/i/Hg pressure for 24 hours. 



Diets 5 through 9 were the artificial formulations. Tetra Marin (Diet 5) is a 

 commercial flake diet used in aquarium fish applications and consists of 

 unknown proportions of meals from fish, crab, mussel, lobster, beef heart, and 

 brine shrimp. In addition, it is made up of such components as halibut liver, 

 Calanus finmarchicus , kelp, oatflour, wheat germ, Agar-Agar, seaweed, and 

 bone charcoal. The other four artificial diets were modified formulations 

 originally prepared to suit the requirements of Atlantic salmon. The diets were 

 prepared by the Tunison Laboratory of Fish Nutrition, U.S.F.W.S., Cortland, 

 New York. The composition of these diets is given in Tables 1 5-2 and 1 5-3. 



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