YAN(; anri LIVINGSTON: FOOD HABITS OF GREENLAND HALIBIT 



Table 3— Daily ration (D R ) and mean stomach content weight 

 (%BW ± SE) of Greenland halibut during each 3-h period. BW 

 = body weight; N = No. of stomachs (including empty stomachs). 



ation rate (/?) is affected by prey type, the constant 

 a, used to calculate R for each size group, was deter- 

 mined by the percentage by weight of the main prey 

 items (fish or squid). In size group 30-49 cm, where 

 fish constituted 72% and squid constituted 25% by 

 weight of the diet, both a = 0.0143 (fish as prey) 

 and a = 0.0079 (squid as prey) were used for cal- 

 culating R. For size group 50-69 cm, fish constituted 

 47% of the diet and squid 52%, so gastric evacua- 

 tion rates were also calculated by using both a = 

 0.0143 and a = 0.0079. For size group ^70 cm, prey 

 fish comprised 94% of the diet, and a = 0.0143 was 

 used for calculating the gastric evacuation rate. 



Large Greenland halibut (>70 cm) had the highest 

 daily ration value (1.17%), measured as percentage 

 of body weight per day (B WD), followed by the size 

 group 30-49 cm (0.66% BWD). The 50-59 cm size 

 group had the lowest daily ration value, 0.64% BWD 



c/^ 



5r 







>70cm 



28 

 25 



22 



40 



41 33 



J- 40 



21 t 



} 



J I I L 



3r 



2 - 



1 - 







50-69 cm 

 78 108 



97 111 



49 



I 



n|j.,{{ 



J I I L 



30-49 cm 



52 



27 



64 



I 



J L 



44 



5 



59 



34 



I 



■L 49 



i 



J I  ' I 







12 18 



Time (hours) 



24 



Figure 6.— Die) changes in mean stomach content weight (%BW 

 ± SE) in the stomachs of three different size groups of Greenland 

 hahbut (the number above each bar was the sample size). 



687 



