26 



Part III. — Twenty-eighth Annual R&poii 



Months when the 



Stomachs were 



examined. 



Total number 



of Stomachs 



examined each 



month. 



Nvimber witli 



food that could 



be identiiied. 



Number emptj', 



or with food 



that could not 



be determined. 



1910 



September 1909 



Occober ,, 



l^ovember ,, 



December ,, 



January 



Februaiy 



March 



April 



May 



June 



Totals for the ten 

 months. 



21 stomachs 

 115 

 101 

 167 



91 „ 

 160 



83 

 124 „ 



95 „ 

 119 



1076 



12 stomachs 



74 „ 



53 



117 „ 



59 

 125 



68 „ 



84 „ 



60 „ 



62 „ 



714 



9 empty 



41 „ 



48 „ 



50 ., 



32 „ 



35 „ 



15 „ 



40 „ 



35 „ 



57 „ 



362 



It will be observed from the preceding table that the total number of 

 halibut stomachs examined was 1076, and of these 362 (about 337 per cent.) 

 were empty, or the nature of the contents could not be determined, while 

 the remaining 714 contained food which consisted of organisms that could at 

 least to some extent be identified. 



It will also be observed that during the several months the proportion of 

 empty stomachs differed sometimes considerably ; this difference, however, 

 may not be due to natural causes. Sometimes it could be explained by the 

 fact that some of the stomachs available for examination were those of "welled 

 fish" — fish which had been on the ship for a number of day.<!, and kept alive in a 

 tank fitted up for the purpose in the ship's hold ; any food, therefore, the 

 stomach may have contained would be more or less completely digested by 

 the time they were brought to the market. Sometimes also the food may 

 have consisted of only soft-bodied organisnis, such as cuttlefishes, which are 

 quickly reduced to unrecognisable pulp ; in other cases, the only evidence 

 that the fish had recently been feeding was the presence in the intestine of 

 partially eroded otoliths, or other less digestible substances. 



In comparing the food contents of the stomachs examined from month to 

 month, slight differences in the constituents of the food have also been 

 observed. For a while Crustacea, especially such forms as hermit crabs 

 {Eupagurus) and Nephrops, were of frequent occurrence, but in the latter 

 months, i.e., from March onwards, Crustacea have not been so often met 

 with ; while on the other hand. Gadoids, such as haddocks and whitings, 

 but other fishes as well, have constituted the principal part of the food, and 

 sometimes was the only kind observed. 



In the following summarised statement a description of the food observed 

 in the stomachs during each of the ten months from September 1909 to 

 June 1910 inclusive, is given. 



September 1909. 



Twenty-one halibut stomachs were examined in September, and of these 

 12 contained food that could be identified. The food in one of them consisted 

 of fragments of Spatangus purpurea and Fusus, that of another consisted of 

 starfish discs and arms. In a third the food consisted of remains of fish and 

 a Decapod crustacean, while the contents of the others consisted entirely of 

 fishes, among which were the remains of haddocks and whitings and a fairly 

 large herring. 



