FISHES OF THE GULF OF MAINE 



51 



be hauled in; when a long line, with 1,500 hooks, 

 has been known to bring in a dogfish on nearly 

 every hook ; and when an average trawl catch of 

 6,000 to 8,000 per trip was made on Georges Bank 

 in 1913 during their season of abundance. At 

 the time of the 1904 to 1905 peak it was estimated 

 from recorded catches that at least 27,000,000 

 were being taken yearly off the coast of Massachu- 

 setts. 35 



More precise information from waters farther 

 north is that 10,391,000 pounds, or 2 to 3 million 

 individual dogfish, were caught in 1938, in Pla- 

 centia Bay, Newfoundland, with no apparent 

 effect on their numbers. 36 In short, they may be 

 as plentiful in our Gulf as they are on the Cornish 

 coast, where the record catch of 20,000 in a single 

 haul was made many years ago. 



Spiny dogfish appear to have been more numer- 

 ous in the Massachusetts Bay region during the 

 last quarter of the past century and during the 

 early nineteen hundreds than they had been pre- 

 viously. At Woods Hole, on the contrary, they 

 are said to have been much more plentiful before 

 1887 than they have been at any time since. To 

 a certain extent, of course, reports of fluctuations 

 in abundance from year to year must be discounted 

 as reflecting the movements of the great schools 

 that may visit one part of the coast one summer 

 and another part the next, not a general altera- 

 tion of the stock. But the many fishermen who 

 reported to the Massachusetts Commissioners in 

 1905 were unanimously of the opinion that dogfish 

 had multiplied steadily for 20 to 30 years past, 

 and reports from British coasts were to the same 

 effect. Perhaps the years 1904-1905 marked the 

 apex of this wave of multiplication; at any rate 

 dogfish were reported as distinctly less troublesome 

 to the mackerel netters in 1913 than they had 

 been previously. And little complaint has been 

 made of them in late years. 



But it is not safe to conclude from this that the 

 stock is at a low ebb at present, for it was the hand- 

 and long-line fishermen that suffered most from 

 them; and it is only as they increase the amounts 

 of trash fish dumped overboard that the dogfish 

 bother the otter-trawlers. 



Importance. — During the years when the ground 

 fishery was chiefly by hook and line, fishing often 

 was actually prevented by dogfish in Massachu- 



» Report, Comm. Fish and Game, Mass., (1906), 1907, p. 20. 

 » Templeman, Newfoundland Fish. Res. Bull., 15, 1944, p. 72. 



setts and Ipswich Bays, unless cockles (Polynices) 

 were used for bait, for dogfish do not take these. 

 The general replacement of hook and line fishing 

 by the otter trawl has put an end to widespread 

 complaints on this score. But when schools of 

 dogfish get into a net or seine, they so snarl the 

 twine that disentanglement and repair may be the 

 work of days. And it has been estimated that 

 they may do some $400,000 worth of damage 

 annually to fishing gear, and to fish caught by 

 such gear, off the coast of Massachusetts alone, 

 during their peaks of abundance there. 



With the dogfish so plentiful and destructive, 

 it is no wonder that serious efforts have been made 

 to make them a source of revenue instead of a 

 dead loss. And the dog is a far better food fish 

 when fresh than is generally appreciated, as is 

 evident by the large amounts landed in the fishing 

 ports of northwestern Europe. But it has never 

 been in any demand for the table, on our coasts, 

 though it would offer a large supply of cheap food 

 were a satisfactory method found for canning it. 

 During their more recent periods of plenty various 

 efforts have been made to utilize them on a large 

 scale for fertilizer, and for liver oil (it compares 

 favorably with cod for vitamin A, though it is 

 much poorer in vitamin D) , on the Atlantic coasts 

 of the United States and Canada; however such 

 developments have been short-lived. And dogfish 

 have not been of sufficient value up to the present 

 to compensate for a hundredth part of the damage 

 they do. 37 



Black dogfish Centroscyllium fabricii 

 (Reinhardt) 1825 



Bigelow and Schroeder, 1948, p. 482. 

 Garman, 1913, pi. 10, figs. 5-8. 



Description. — The notched margin of the upper 

 tail lobe distinguishes this shark at a glance from 

 the spiny dogfish, with which it agrees in having a 

 long pointed spine at the front edge of each dorsal 

 fin. It differs further from the common dogfish 

 in that its dorsal spines are deeply grooved along 

 each side, whereas in the "dog" they are rounded; 

 in the location of the pelvic fins, the rear axils of 



87 For further discussion of the damage done by dogfish and of their com- 

 mercial possibilities, see Ann. Rept., Comm. Fish. Oame Mass. (1905), 1908, 

 pp. 97-169; Rept. U. S. Comm. Fish. (1902) 1904, pp. 228-229; Field, Doc. 

 622, Rept. U. S. Comm. Fish. (1906) 1907, pp. 21-23; Field, Bull. U. S. Bur. 

 Fish., vol. 28, 1910, pp. 243-257; Mayor, Contr. Canad. Biol. (1918-1920) 

 1921, pp. 125-135; and Templeman, Newfoundland Fish Res. Bull. 15, 1944 



