58 
Fishery Bulletin 119(1) 
M. poutassou : M. merluccius 
200 
Size (mm) 
P. blennoides T. minutus 
300 200 
Size (mm) Size (mm) 
G. biscayensis 100 : ‘ Z M. macrophthalma 
90 130 200 
Size (mm) Size (mm) 
G. argenteus 
%NV 1st major prey group 
%\V 2nd major prey group 
Size at first maturity 
Size classes 
100 120 140 
Size (mm) 
Figure 2 
Trends in volume index (%V) values for the first and second major prey groups in relation to sizes of speci- 
mens of 7 species of Gadiformes caught in the western Mediterranean Sea during 2011-2017. These graphs 
were used in a qualitative method to identify the size at which the trophic strategy changed for each species 
studied. This size is considered the cutoff between small (gray shaded area) and large size classes for each 
species. Sizes are given as total lengths. Arrows indicate the size at first maturity for each species, except 
for the Mediterranean bigeye rockling (Gaidropsarus biscayensis) and Mediterrenean ling (Molva macroph- 
talma) because this information was not available for these species. The other species studied include the 
blue whiting (Micromesistius poutassou), European hake (Merluccius merluccius), greater forkbeard (Phycis 
blennoides), poor cod (Trisopterus minutus), and silvery pout (Gadiculus argenteus). 
