FISHERY BULLETIN: VOL. 75, NO. 3 



a = coefficient of proportionality 

 p = plankton concentration. 



After integration, the function becomes: 



r = R (1 - e~ a P). 



Use of this relationship in analyzing winter 

 flounder feeding as influenced by prey densities of 

 0.68-47.8 cal/liter, or 0.1-7.0 nauplii/ml, yielded 

 some interesting results (Figure 2). Feeding was 

 reasonably constant in the youngest fish with an 

 asymptote being reached quickly at the lower prey 

 concentrations. Five-week-old larvae displayed a 

 rather classic form of the Ivlev curve with food 

 intake increasing with prey density, reaching a 

 maximum at approximately 6.8 cal/liter or 1.0 



nauplius/ml, and then remaining quite stable. 

 The oldest larvae, prior to metamorphosis, showed 

 an increasing food intake through the whole 

 range of plankton densities 1 , right up to 47.8 

 cal/liter or 7.0 nauplii/ml. In general, there 

 appeared to be an increasing of the upper limiting 

 level of food concentration and a decreasing of the 

 coefficient of proportionality (a) with increasing 

 larval age. 



Digestion Rate 



Winter flounder larvae were known to be con- 

 tinuous, visual daylight feeders from prior re- 

 search. Preliminary attempts at establishing 

 digestion rates and unpublished results of night 

 feeding experiments showed that larvae at- 



0.0 



6.8 



13.6 20.4 27.2 34.0 40.8 47.6 



PREY CONCENTRATION <Crt_/L> 



54.4 



61.2 



68.0 



FIGURE 2.- 



532 



-The relationship between planktonic prey concentration and feeding intensity expressed as stomach ration for different 



aged winter flounder larvae at 8°C. 



