nauplii/hr/larva at 23°C to 17.6 nauplii/hr/larva at 29°C. These rates increased 
exponentially as larvae grew, so that larvae were consuming 53.8 
nauplii/hr/larva at 23°C and 142.7 nauplii/hr/larva at 29°C at 16 days of age. 
Rations, in terms of numbers of nauplii and dry weight consumption, were 
then calculated. Specific ration also was calculated, and it tended to decrease as 
larvae grew, particularly at the highest temperature (29°C), where it was 220.8 
percent at two days after hatching but decreased to 79.7 percent at 8 days. 
This result is similar to that of Laurence (60) for winter flounder (8°C), where 
specific ration decreased from over 300 percent for the smallest larvae to about 
30 percent for metamorphosed individuals. Mean gross growth efficiency of sea 
bream (92) varied from 23.9 to 30.6 percent, the highest value being obtained 
to the lowest temperature (23°C); there was no evidence that growth 
efficiency changed with age. Mean growth efficiencies were similar to those for 
winter flounder (60), except that first feeding winter flounder had low growth 
efficiencies, which increased rapidly during the first few days of active feeding. 
The relatively high growth efficiency of sea bream, when it begins to feed, 
suggests that food is less critical for it than for winter flounder at that stage, a 
suggestion supported by the relatively low required prey concentration for 
survival of sea bream larvae (45). 
Starvation Criteria 
Because starvation is suspected as a major cause of larval mortality, 
biochemical, histological, and behavioral criteria have been developed for some 
species to show changes that occur when the food supply is inadequate. These 
techniques eventually may be used to characterize starving larvae collected at 
sea. Biochemical methods also have been used to show how laboratory-reared 
larvae differ from wild larvae. When supported by morphometric data, 
biochemical criteria hold promise to evaluate how types and amounts of food 
affect larval condition. 
The biochemical composition of laboratory-reared, larval Atlantic herring 
and plaice was studied by Ehrlich (32, 33). He found that water, triglyceride, 
carbohydrate, nitrogen, carbon and ash content varied as a percentage of body 
weight as larvae grew, In starving larvae both relative (percentage) and absolute 
changes in amounts of those substances were measured, the relative changes 
often being a better measure of starvation than the absolute changes. 
Percentage of water increased about four percent in starved larvae of both 
herring and plaice, while percentages of triglyceride, carbohydrate, and carbon 
decreased. Percent nitrogen decreased in starved plaice larvae but did not 
decrease in herring; absolute amounts of nitrogen decreased in both species. 
Ash percentage of both species increased rapidly during starvation. Ehrlich (32, 
33) concluded that the “point of no return” was not defined by an abrupt 
change in the chemical composition at some point during starvation, but rather 
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