130 DEPARTMENT OF THE NAVAL SERVICE 



4. THE DISTRIBUTION AND USES OF THE COMMON SELACHIANS OF 



EASTERN CANADA. 



(a) SHARKS AND DOGFISHES. (1^) 



Squalus acanthias Linnaeus. 



Synonyms — 



Squalus acanthias Linnaeus. 

 Squalus acanthias Jordan and Gilbert. 

 Acanthias americanus Storer. 

 Acanthias vulgaris Risso. 

 Acanthias vulgaris Giinther. 



Common names — 



Dogfish; Picked dogfish; Horned dogfish; Bonedog; Skittle-dog; Spiny 

 dogfish. 



Characteristics: Body slender; head depressed, about 6^ times in length; depth 

 about 8 times in length; snout pointed; eyes lateral without nictitating membrane; 

 mouth inferior, rather large, slightly arched, a long, straight, deep, oblique groove 

 on each side; nostrils inferior, separate; spiracles rather wide, just behind the eye; 

 gill openings moderate, all in front of the pectoral fins; dorsal fins two, the first 

 larger than the second and much in advance of the ventrals which are behind the 

 middle of the body and in advance of the second dorsal ; each d'orsal fin armed with a 

 strong ungrooved spine, the first about two-fifths height of fin, the second about three- 

 fifths height of fin; anal fin wanting; caudal fin with the lower lobe small and the 

 upper lobe slightly bent upward; ventral fins inserted posteriorly, not much before the 

 second dorsal. Slate colour above, pale below, back with oblong, whitish spots, 

 especially in the young. Length, 2 to 31 feet; weight,' 5 to 15 pounds. 



This is the common Canadian dogfish; it is stated by Giinther to occur in the 

 temperate seas of the Southern as well as the Northern hemisphere but not in the 

 intermediate tropical zones. 



Cornish (1907) writes concei^ning this fish at Canso: "This is an extremely 

 common species and often a great nuisance to the fishermen fishing with -trawls of 

 baited hooks. I have known gear with YOO hooks to have 690 of these dogfish upon it. 

 No use is generally made of these fish; they are difficult to release from the hooks, and 

 ihey generally snap off the snood; they are regarded with much disfavour." As Pro- 

 fessor Prince pointed out in his report on the " Dogfish Pest in Canada" (Fisheries 

 Report, Department of Marine and Fisheries, Ottawa, 1903), this species has proved 

 a most destructive enemy to the sea fisherman's pursuits, and his recommendations to 

 the Government favouring reduction works for converting dogfish into fertilizer, oil 

 and glue, etc., are being carried out." 



Concerning this fish at Tignish, Prince Edward Island, Cornish further writes : 

 "The picked dogfish is very common and extremely destructive. It appears about the 

 end of July and remains until the end of the fishing season in the autumn. It is 

 noticed on the east a few days before it reaches the west coast (of Prince Edward 

 Island). As a result of its appearance fishing for cod may often cease entirely early 

 in August ; the trawls of hooks are set for cod at night and when raised in the morning 

 sometimes every fish has been devoured by this pest, only the head and vertebral 

 column remaining on the hook. The females were generally gravid, containing four 

 or five well -developed embryoes about 15 cm. long." 



13 The names and characteristics are taken in large part from Jordan and Evermann 

 (1896). 



