FISHERY BULLETIN: VOL. 80, NO. 4 



PLEURONECTIFORMES 



20 



15 CM LENGTH CLASSES) 



Figure 4.— Three dimensional plot of the diet overlap of Atlantic cod with selected pleuronectiform fishes. 



Silver Hake — Redfish 



High levels of overlap occur between 16-20 cm 

 (size class 4) silver hake and 11-45 cm (size 

 classes 3-9) redfish (Fig. 5B). The peak value is 

 75% for 31-35 cm (size class 7) redfish and these 

 smaller silver hake. Most of this overlap is due to 

 predation on the euphausiid Meganyctiphanes 

 norvegica, which accounted for 60% and 63% of 

 the diet of these 16-20 cm silver hake and 31-35 

 cm redfish, respectively. The other high overlap 

 values between these two predators can also be 

 attributed to euphausiids making up more than 

 50% of the diets. Medium levels of overlap, 30- 

 42%, were found for other size silver hake and 

 redfish. Once again Meganyctiphanes norvegica 

 was a major dietary item but in some cases Di- 

 chelopandalus leptocerus also contributed sig- 



nificantly. For the larger silver hake (>35 cm, 

 greater than size class 7) there was little, if any, 

 diet overlap. These large silver hake prey heavily 

 on fish while redfish are predominantly crusta- 

 cean predators. 



Silver Hake — Longhorn Sculpin 



Intermediate diet overlap values occur be- 

 tween silver hake ranging from 6 to 15 cm in 

 length (size classes 2-3) and most of the size 

 classes of longhorn sculpins examined (Fig. 5C). 

 This overlap is due to both predators' reliance on 

 crustaceans such as Crangon septemspinosa, 

 Dichelopandalus leptocerus, and Neomysis amer- 

 icana. For the larger silver hake, those that are 

 primarily piscivorous, there is virtually no over- 



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