ri(n<KD DOG-FISH. 



IKIl 



of the liii, and the. naked tij) of eai'li spine projects 

 only a very little wma' al)c)\e tiie skin. Tiie lireadth 

 of the caudal and pectoral tins is also rather greater 

 in proportion to their length. Somewhat smaller {(b- 

 tuses, 15 — 111 cm. long, with tlie large vitelline sac still 

 attached in tlie form of a, peai- 7 cm. long, with a stalk 

 measuring 2\/„ cm., have a dec]) groove, like a seam, 

 along the under surface of the snout. Their fin-spines 

 are so short that the tips have not emerged from their 

 scaly dermal envelope, ^\'hich occupies, however, as 

 great a portion of t lie tin-margin as in adult specimens. 

 In the males only (piite indistinct rudiments of the 

 pterygopodia, act yet protruding from the skin, are 

 visible. The coloration is full}' developed. The young 

 are not born until the j'olk has been entii-ely absorbed, 

 and may then have attained a length, as mentioned 

 above, of 25 cm. 



The Picked Dog-lish has a very e.xtensive geogra- 

 phical range. In the North Atlantic this includes the 

 most northerly parts of Europe, Iceland, and the east 

 coast of the United States, as weW as the west coast 

 of Europe and the Mediterranean. To the south the 

 species has been found off the Cape of Good Hope, the 

 Mascarene Isles (Dumekil), and on the coast of Australia 

 (Richardson and GOnther)- In the Pacific it is also 

 known from Chili (Molina), Japan (Schlegel), and 

 Behring Island (the Vega Expedition). It is conse- 

 quently to be regarded, we nn^^" almost say, as a cos- 

 mopolite. Throughout the west coast of Scandinavia 

 it is common, and it penetrates, though more rarely, 

 into the Baltic to the east coast of Riigen (Mobius and 

 Hkincke) and to the north-east of Scania (Wallengren"). 



In Scania, Bohuslan, and everywhere in Norway 

 the Picked Dog-fish is called Hd (Haa). In Sweden 

 the name is written Jiaj, probably from some German 

 or Dutch dialect. (_)ther, less usual names are: Piggltd 

 or Hdfisk, in Iceland Hafr or Haaftir, on the Faroe Is- 

 lands Haavur, in Scania Hdkatt or Hafsliati. The name 

 of hd (Shark) seems to have been everywhere applied 

 among the Gothic nations by preference to this species, 

 the commonest Shark; and the other forms have been 

 distinguished by the addition of some sutiix, as Hd- 

 hvand (the Porbeagle), Hdsforje (the Tope), Hdmcir, 

 Hdkdring, or Hdkal (the Greenland Shark). 



The Picked Dog-fish has its constant habitat on a 

 soft and oozy bottom, but, like most of tlie Sharks, is 



a conlirmed rover. It swims in shoals, and is exceed- 

 ingly voracious. Its food consists both of lower marine 

 animals and of fishes, especially tho.se of gregarious liabits, 

 such as Clupeoids, Garpike, and even Cod or Haddocks, 

 which it bites in two with ease, though they be not 

 much tiiiimer than itself. When Picked Dog-fish ap])ear 

 in shoals, they ai'e a great nuisance to the fisherman, 

 for the}' j)lunder and damage nets set for other fishes, 

 make off with hooked fish or get caught themselves 

 instead, a poor exchange, and olteii bite off the snood 

 above the hook, which is thus lost. They are said to be 

 most numerous early in spring, when they approach the 

 coast in enormous shoals, whose multitude, it is alleged, 

 rivals that of the Herring. A boat's crew, it is stated, 

 can then take several boat-loads in a day. From Norway 

 Sundevall was told that the Herring-shoals are some- 

 times hemmed in near shore by Picked Dog-fish, which 

 keep watch outside. Tiiey are as plentiful on the Eng- 

 lish coast as in Norway, but in Bohusliln they do not 

 seem to occur in quite so great numbers, when the 

 Herring is not there. Stkom, in his descrijjtion of Sond- 

 m5re, says that they withdraw from the shallows at the 

 beginning of April, shortly after the Cod have couw in, 

 after which very many are hooked, about Whitsuntide, 

 in the dee]) fjords. On the coast of Bohuslftn they are 

 again taken towards autumn, first on hand-lines and 

 Haddock-lines, thus in somewhat deeper water, during 

 August and September, when the catch is said to consist 

 almost exclusively of males, and later on, in October, 

 when they are said often to penetrate far up the fjords 

 and to remain there until the frost sets in. During 

 winter they are not met with on the said coast, except 

 when the Herring is there, possibly because they are not 

 sought after in the deep M'ater where they pass this season. 

 Aristotle stated that on the coast of Greece this 

 fish copulates in August and brings forth its young 

 from May till August. The case is a])parcntl}- as a 

 rule the same in Scandinavian waters. Ekstrom con- 

 cluded from his observations in Bohuslan that the 

 breeding is performed in shoals during August or Sep- 

 tember in rather deep water. According to many cor- 

 roborative statements the voung are l)orn most ])lenti- 

 fullv at the end e)f April and the beginning of Jlay 

 and afterwards, in less number, throughout the summer. 

 \\'. V. Wright states that during spring the females 

 assemble in large companies near land, in small pools 



Ofvers. Vet. Akftd. Fork. 18(56, No. I, p. 5. 



