INTRODUCTION 



The Atlantic silverside, Menidia menidia, is a marine fish used in bioassay 

 studies due to its relative sensitivity to environmental contaminants (17). 

 Bioassays using silversides have been relatively short-term studies, principally 

 because of the dependence upon wild fish populations. Before long-term 

 studies are possible, the dietary aspects of laboratory culture technology must 

 be developed. The diet can affect the organism's ability to respond in a 

 reproducible fashion. Additionally, the diet is an important feature in the 

 ability of cultured fish to reach maturity, and spawn viable eggs necessary for 

 multi-generation bioassay evaluations. 



Live brine shrimp, Artemia salina, have been used world-wide in the 

 laboratory culture of larval marine fish (4). Silversides used in toxicological 

 bioassays by the Environmental Protection Agency's Environmental Research 

 Laboratories have commonly been fed brine shrimp as their primary diet. 

 However, the difficulty of culturing large volumes of biochemically similar 

 brine shrimp (8), coupled with increased costs and decreased availability (32) 

 of cysts has mandated the need for an artificial diet. Providing an adequate, 

 practical, and economical diet is a major factor limiting culture of most marine 

 fish reared on either a laboratory or commercial scale. Based on these facts, 

 the University of Rhode Island, Food Science & Technology, Nutrition and 

 Dietetics Department collaborated with the Environmental Research 

 Laboratory to evaluate a number of artificial diets that could replace brine 

 shrimp. 



In our study, we were attempting to produce a cultured fish that could 

 respond in bioassays in a similar manner to wild fish, and provide comparable 

 growth and survival as brine shrimp fed juvenile fish. This paper discusses the 

 effects of various diets on the protein and lipid composition of laboratory 

 reared silversides. 



EXPERIMENTAL 



General 



This study consisted of three parts: 1) a two month batch culture of 

 silversides fed 3-day-old brine shrimp, 2) a preliminary evaluation of an 

 artificial Atlantic salmon, Salmo salar, diet comprised of a soybean oil base 

 and 3) an expanded study using brine shrimp and a number of artificial diets. 



Culture 



The collection of the gravid female silversides, the stripping and fertilization 

 of the eggs, the hatching and feeding procedures, and the culture systems used 



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