* FISHES OF THE GULF OF MAINE 415 



water (p. 417), probably preferring certain small copepods, on which young cod of 

 12 to 18 mm. have been seen feeding exclusively at Woods Hole.''" 



The fact that the young of the closely related European whiting {Gadus merlangus) 

 and European pollock (Gadus pollachius) not only live almost wholly on copepods but 

 discriminate between the various kinds makes it the more likely that cod do the same. 

 This same diet, varied with amphipods, barnacle larvae, and other small crustaceans, 

 as well as with small worms, is the chief dependence of the little cod when they first 

 seek the bottom," but as they grow larger they become ground feeders chiefly and 

 consimie invertebrates in great variety and enormous amount. Mollusks, collect- 

 ively, are probably the largest item in the cod's diet in the Gulf of Maine, and any 

 shellfish that a cod encounters is gobbled up, so that cod stomachs are mines of 

 information for students of mollusks. Large sea clams (Mactra), the empty shells 

 of wliich are often found neatly nested in cod stomachs, cockles (Lunatia), and 

 sea mussels (Modiola) are staples, all of which they swallow whole. Cod also 

 eat crabs, hermit crabs, lobsters (large and small), prawns, brittle stars (of which 

 they are sometimes crammed full '*), sea urchins, sea cucumbers, and blood worms 

 (Nereis). Brittle stars and small crabs, for example, had been the chief diet of the 

 cod exammed by Welsh on the Isles of Shoals-Boon Island ground in April, 

 1913, while Wilcox (1887, p. 95) states that a number of 17-poimd fish caught in 

 Ipswich Bay were full of large red prawns 2 to 4 inches long. Tunicates ("sea 

 squirts") also bulk large in the diet of the cod. Occasionally they eat hydroids, 

 bryozoans, and algae, perhaps taking them for the amphipods hidden among them. 

 In fact the cod eats any and every invertebrate small enough for it to swallow, but 

 although its diet list would probably prove almost as extensive as that of the had- 

 dock (p. 436) , it shows so decided a preference for large shells rather than small that 

 the stomach contents of cod and haddock taken side by side differ noticeably. Nor 

 is it likely that cod root the bottom as haddock do (p. 436). 



At every opportunity cod pursue and gorge on squid and on various small 

 fish, particularly on herring and launce, also shad, mackerel, menhaden, silver- 

 sides, alewives, silver hake, young haddock, and even on their own young, rising into 

 the upper waters for this purpose when necessary (p. 413). They pick up flounders, 

 cunners, rock eels (Pholis), blennies, sculpins, sea ravens, small hake, skates, 

 and silversides on bottom. In fact they take any fish small enough to swallow, 

 including the hard slim alligatorfish (p. 334), and Welsh noted that many cod taken 

 near the Isles of Shoals on May 1, 1913, spat up small rosefish from 4 to 6 inches 

 long. Adult as well as small cod are also known to feed on pelagic shrimps '° in 

 the waters around Iceland, but we have never heard of them doing so in the Gulf 

 of Maine. Even a wild duck does not come amiss to a large cod now and then. 

 For instance, we have heard of several scoters found in the stomachs of large fish 

 caught off Muskeget Island in 1897, and though sea fowl are not a normal article 



" Bumpus. Science, New Series, Vol. VII, 1898, p. 485. 



" Mcintosh and Mastermana (The Life-Histories of the British Marine Food-Fishes, 1897) and Kendall (1898, p. 179). 

 '« Baird (1889, p. 36) reports this. 



» Schmidt (Skrifter Udgivne af Eommissionen for Havunders0ge!ser, Nr. 1, 1904, p. 70) and Paulsen (Meddelelsor fra Kom- 

 missionen for HaTunders0gelser, Serie: Plankton, Bind I, Nr. 8, 1909, p. 39), 



102274— 25 1 2T 



