all stomachs were included. Some authors 

 have omitted empty or nearly empty stomachs 

 m their calculations . 



The percentage volume method is undoubt- 

 edly the best single criterion for evaluating 

 the relative importance of foods . It was the 

 only method employed in this investigation 

 which gave a measure of the bulk or mass of 

 the various items. "The frequency of occur- 

 rence and number of organisms yielded a 

 useful indication of the availability and quan- 

 tity of the orgamsms eaten. A well-rounded 

 assessment of the comparative value of each 

 food item can be gained by taking into consid- 

 eration all three methods described above . 



Certain species of animals were much 

 more prevalent in the diet than others . No 

 doubt the abundance and availability of particu 

 lar orgamsms to the haddock were important 

 factors contributing to the quantity eaten . 

 Possibly the haddock's preference for particu- 

 lar Items was another factor affecting the 

 quantity taken . Evidence to resolve this 

 question of species abundance has not been 

 ascertained and must await further investiga- 

 tion. And, as explained previously in this 

 report, there was considerable variation in 

 dietary components from one location to an- 

 other, but considering the entire area studied 

 11 species of ammals were especially import- 

 ant in the diet. Judged aocording to the num- 

 ber, frequency of occurrence, and volume the 

 following species were considered to be the 

 most important foods of Georges Bank haddock: 



Byblis gaimardii Kr6"yer Amphipod 



Monoculodes edwardsi Holmes Amphipod 

 linciola irrorata Say Amphipod 



Cancer irroratus Say Rock Crab 



Hyas coarctatus Leach Toad Crab 



Clymenella torquata (Leidy) Annelid 

 Eunice pennata (O . F . MflUer) Annelid 

 Nereis pelagica Linnaeus Annelid 



Echinarachmus parma (Lamarl^Sand Dollar 

 Ophiopholis aculeata (Linnaeus) Brittle -Star 

 Ophiura lobusta Ayers Brittle-Star 



SEASONAL VARIATIONS 



Haddock captured during the spawning 

 period exhibited a pronounced decrease in 

 stomach content volume . Because of the 

 conflicting evidence on this subject it has 

 been uncertain whether or not haddock abstain 

 from feeding during the season for spawning. 

 Information gathered by Welsh (Bigelow and 

 Schroeder, 1953) in 1913 indicated that had- 

 dock are apt to fast during the spawning 

 season. This contention was supported by 

 Homans and Needier (1944). The opposite 

 situation was found by Needier (1930). He 

 reported spawning haddock of both sexes with 

 well filled stomachs . Studies conducted by 

 Vladykov and Homans (1935) and Ritchie 

 (1937) found an intermediate situation to exist, 

 in that only a decline in feeding took place 

 during the spawning period rather than a com- 

 plete cessation. This last view is corrobo- 

 rated by the data obtained in this investigation 

 (table 8) . 



Distinct seasonal trends in diet composi- 

 tion weie not evident although some rather 

 wide variations occurred from month to 

 month . An insist to seasonal trends in di^- 

 ary components was gained by comparing the 

 stomach content composition of specimens 

 taken during six different months from the 

 Northeast Peak, namely, duiing April, July, 

 September, October, January, and February. 

 Data from this analysis are presented in 

 table 9 . 



Four of the more obvious monthly iriegu- 

 larities were the mollusks in the July samples, 

 miscellaneous items in the January samples, 

 and mucus in the January and Febiuary 

 samples. The unusually large percentage of 

 Mollusca in the July samples was due to sev- 

 eral squid of large volume . A few pelagic 

 tunicates ( Salpa) in the January specimens 

 resulted in the unusuaUy high percentage for 

 miscellaneous Items. The quantity of mucus 

 was found to be especially high in January and 

 February samples. These months are the 



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