102 BULLETIN OF THE BUREAU OF FISHEBIES 



differ among themselves in their choice of diet, 50 nor were any of the gadoids common 

 to American and North European waters studied by Lebour. However, several 

 North Sea members of the family were feeding on small copepods — mainly Pseudo- 

 calanus — and Calanus was taken freely as the larval fishes grew in size. Dannevig, 

 too, wfites that numbers of newly-hatched cod placed under observation at the 

 hatchery at Flodevigen, Norway, took no food until the yolk sac had been absorbed, 

 and thereafter fed from the first on such animals as mollusk larva?, nauplii, etc., 

 "seeming to despise the innumerable diatom forms which are likewise present in 

 the water" (Dannevig, 1919, p. 48). Evidently this applies to the American cod 

 as well, because young fish 12 to 20 millimeters long have been observed to feed 

 exclusively on copepods at Woods Hole (Bumpus, 1898), and according to Mead 

 (1898) copepods are likewise the favorite diet there for young sculpins and sand 

 launce (Ammodytes). 



Judging from the general similarity between the planktonic communities of the 

 two sides of the North Atlantic, there is every reason to assume that the dietary 

 lists which Lebour gives for very young herring and mackerel would apply as well 

 (in a general way) to the Gulf of Maine as to the North Sea. For the former species 

 this diet consisted chiefly of larval gastropods, with copepods, particularly Pseudo- 

 calanus, next in importance, barnacle (Balanus) and bivalve larvae in smaller 

 amounts, and with unicellular forms, as just noted (curiously enough, out of about 

 1,000 specimens 8 to 15 millimeters in length over 700 contained no food); while 

 the young mackerel had eaten copepod nauplii (chiefly Calanus and Temora) and 

 crustacean (probably copepod) eggs, with a few ostracods, euphausiid larvae, and 

 even young fish. 



In Norwegian waters, according to Nordgaard (1907), the older herring feed 

 chiefly on euphausiids and copepods, especially the genera Calanus and Temora, 

 with ostracods, tintinnids, larval barnacles, Halospha?ra, and other small members 

 of the plankton consumed in smaller amounts. Copepods and -euphausiids together 

 constitute almost the entire diet of the herring in the Gulf of Maine, with fish smaller 

 than about 4 inches long taking chiefly the former and larger ones taking both at 

 localities where they are available (Moore, 1898; Bigelow and Welsh, 1925, p. 103). 

 Young herring, taken while feeding on the surface at Woods Hole, have been found 

 full of copepods of several species. What is known of the feeding habits of the 

 alewife {Pomolobus pseudoharengus) , and blueback (Pomolobus sestivalis), is to the 

 effect that they also subsist chiefly on these two groups of Crustacea during the part 

 of the year when they are in salt water, and that shad (Alosa sapidissima) subsist 

 on copepods and mysid shrimps. Mackerel, in the Gulf of Maine, have also long 

 been known to feed greedily on calanoid copepods (the "red feed" or "cayenne" of 

 which fishermen often describe the fish as crammed full) . I have found fish, taken 

 off Cape Elizabeth, August 12, 1912, packed with Calanus finmarchicus and Pseudoca- 

 lanm elongatus; Goode (1884a) found the stomachs of mackerel, taken off Portland in 

 1874, full of large, copepods and euphausiids. The schools of mackerel frequenting 

 the Bay of Fundy have also been reported as following and preying upon the shoals of 



" So far as I can learn there is no record of the stomach contents of the larval witch (Glyptocephalus) or American plaice 

 (Hippoglossoides). 



