FISHERY BULLETIN: VOL. 80, NO. 3 



Table 2.— Diets by percentage frequency of occurrence, number, and point volume and diet diversity by number of taxa consumed 

 (P) and diversity index (H) of fishes of the genus Notothenia collected off Antarctic Peninsula, 1975. See text for explanation of terms. 



Fish are a major part of the diet of N. neglecta 

 and Paracfiaenichthys charcoti by volume but 

 were unimportant by number. 



Changes with Locality 



In N. gibberifrons, N. larseni, T. scotti, and H. 

 bispinis, the diets of individuals of a similar size 

 group caught at the same time of year but in dif- 

 ferent localities showed significant differences 

 in the prey taken (Fig. 2) and in the amount of 

 food consumed (Table 5). In each species, approx- 

 imately the same number of prey taxa were con- 

 sumed, but only in H. bispinis were the taxa 

 identical. The other species consumed not only 

 different amounts from each taxa, but also dif- 

 ferent types of prey. This change in diet is most 

 dramatic in N. gibberifrons (Fig. 2). Individuals 

 from the more northerly Peltier Channel tended 

 to consume sedentary invertebrates such as 

 sedentary annelids, clams, and cumaceans which 



are often found buried up to several centimeters 

 in the mud. Individuals from the samples of the 

 southern Terra Firma Islands tended to con- 

 sume motile, rubble-bottom organisms, such as 

 errant polychaetes, amphipods, and fish. 



Ontogenetic Changes 



Sample sizes were large enough in six species 

 to compare differences in diet with fish size. 

 Within each species, individuals collected from 

 the same locality at the same time but of differ- 

 ent size tended to consume prey from the same 

 taxa, but the relative importance of each taxon 

 by volume varied significantly (x 2 , P<0.02)(Figs. 

 3, 4). In all species mean prey size, mean number 

 of prey items consumed, and number of different 

 prey types consumed increased with fish size. 

 Diet diversity showed no size-related change in 

 any species except in T. bernacchii (Table 6). 



580 



