674 NATURAL HISTOET OF AQUATIC ANIMALS. 



mackerel, and disappear shortly before them, I judge that they probably need warmer water than 

 that fish, and therefore do not probably go quite so far north. When they first appear they are 

 in great abundance; the females always excel in numbers the males; but in the early part of 

 the season all are females, and all have young in some stages of development, though not in every 

 stage, there being seldom any between the young just forming and those nearly grown. The 

 gravid females may be found with the young in some stages of development during the whole 

 season. The mature male weighs five or five and a half pounds, rarely as much as six pounds, 

 while the female attains the weight of eight or eight and a half pounds. In spring they are 

 poor, and their liver is of a dark color and lean ; but in autumn it is quite fat and large, and the 

 amount of oil does not increase proportionately with the enlarged size of the liver, but rather 

 decreases. In the Gadidw, on the contrary, the liver when in poor condition affords no oil. Fat 

 is also found in the flesh of the Dogfish, which is sometimes used for fuel, burning well when 

 dried."! 



The same authority also writes: "When I first began to go fishing, in 1810 to 1820, the 

 Dogfish fishery was considered one of the most valuable fisheries that we had around the shore. 

 They appeared here in the spring, and were very plenty, and, would last a day or two and then 

 all would be gone. Then you would not see a Dogfish again all summer; but about the 10th, or 

 middle of September they came to us again returning south. They would stay into November,, 

 and during that time the fishermen would get — a man and a boy — all the way from eight, ten, to 

 fifteen barrels of oil. Twenty -five years ago we would occasionally see Dogfish in the summer. 

 The last fifteen years they have been here all summer. During the war they were plenty all 

 summer and the livers sold for one dollar a bucket, and now they are not worth but twenty and 

 twenty-five cents. The female Dogfish is a good deal the biggest. I have known of Dogfish to 

 be with full-grown young in November." 



The annoyance which is caused by the presence of Dogfish may be judged from the fact 

 that a trawl line, upon which were five hundred hooks, set by the Fish Commission party of 

 Gloucester in 1878, had nearly one hundred and forty hooks bitten off by the Dogfish at one 

 setting. 



About Cape Ann the Dogfish do not come near the shore. Capt. S. J. Martin, an experienced 

 fisherman, assures me that he has never seen one within three miles of land off Gloucester. They 

 leave Cape Ann, for the most part, before October, and remain on George's Bank until December. 

 They go upon the shoals of George's about the 20th of May, and stay all summer in the shoal 

 water, especially, at a depih of thirty- five to forty fathoms, on the western part. 



In addition to the oil yielded by these little Sharks, the skin is of considerable value, and will 

 doubtless in future be more highly prized than it is at present. It is used by the fishermen 

 to polish their metallic mackerel-jigs, and sometimes in polishing the fancy wood- work on ship- 

 board. If properly brought into notice, the Dogfish skins would perhaps be used to advantage 

 in many departments of metal- working. 



In Southern New England this fish is called the " Bone-fish," in the Orkneys, the " Hoe." 



Couch remarks : " It is the most abundant of the Sharks, and is sometimes found in incalcu- 

 lable numbers, to the no small annoyance of the fishermen, whose hooks they cut from the lines in 

 rapid succession. I have heard of twenty thousand being taken in a seine at one time ; such is the 

 strength of instinct that little creatures, not exceeding six inches in length, may be found in 

 company with the larger and stronger, following schools of fish, although at that time it is impos- 

 sible that they could be able to prey." 



'Proc. Bost. Soc. Nat. Hist., x, 1864-'66, pp. 81-82. 



