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 the 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 fishes (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 
fishes 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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