a 9 2 THE FISHES OF THE NORTHERN SEAS 



specific title from an idea that they are as destructive to other members of their own 

 tribe as sharks. As a matter of fact, their food consists almost entirely of shelled 

 molluscs, crabs, and sea-urchins, for seizing and crushing which their armature of 

 teeth is adapted. The misnomer is not restricted to the name wolf-fish and its 

 Latin equivalent, for the name Anarrhichas, bestowed in 1560, refers to a notion 

 that the wolf -fish is in the habit of climbing out of the water on to the rocks. 

 Wolf-fish is not the only name for the species, for, in common with many other kinds, 

 it is known as " cat-fish," or its Scandinavian equivalent Halfkatten, while in the 

 Orkneys it is termed " swine-fish," on account of a pig-like movement of the nostrils. 

 Wolf-fishes, of which there are several species in the colder seas of the northern 

 hemisphere, live in deep water, where there is a complete absence of light, and only 

 enter the shallows during the spawning season, when they remain quiescent during 

 the day and are active only at night. The voracity of these fishes is exemplified 

 by the fact that at least five quarts of sea-urchins were taken from the stomach of 

 an American specimen ; while in that of a second was found an equal quantity of 

 sea-urchins and whelks, the shells of many of the latter being merely cracked. 

 In other instances the contents of the stomach have included scallops, crabs, 

 hermit-crabs, and brittle-stars, so that the nature of the food seems to depend on 

 local conditions. A remarkable habit, apparently connected with feeding, was 

 recorded in 1886 in connection with the Alaskan wolf-fish (A. lepturus). Attention 

 was directed to a mass of turf floating in the sea and undergoing strange move- 

 ments. A native stated that these movements were due to a wolf-fish, and when 

 a canoe was brought close to the sods this was found to be true, the fish being seen 

 tearing at the grass, and not desisting till driven off with a paddle. So well is this 

 habit known to the natives that they are accustomed to catch wolf-fish by means 

 of hooks baited with grass roots. Such attacks on floating masses of vegetable 

 matter are for the purpose of obtaining crabs and molluscs that may be lurking 

 in these sods rather than for the sake of eating the grass. 



To another group belong the well-known sticklebacks, all of 

 Sticklebacks. . . , & . 



which can exist in the ocean, although the majority prefer fresh 



water. The exception is the fifteen-spined species (Gasterosteus spinachia), which 

 never leaves salt or brackish water. This species is restricted to European seas, 

 where it ranges northwards from the Bay of Biscay. Indeed the whole group is 

 either arctic or temperate in distribution. Sticklebacks, as mentioned in an earlier 

 chapter, build nests, which are guarded by the males. 



A most important group is the cod tribe (Gadidce), in which the 

 soft, dorsal fins (varying in number from one to three) extend along 

 the greater part of the back, and the pelvic pair, which are situated far forwards, 

 may include several rays or be reduced to mere filaments. 



The common cod (Gadus morrhua), though varying much in colour and size, 

 may always be distinguished by the white lateral line. Like all the other species 

 of its genus, it has three dorsal and two anal fins. Next in importance as a food- 

 fish is the haddock (G. ceglefinus), characterised by the lateral line being black. 

 Both kinds inhabit the North Atlantic above the fortieth degree of latitude. The 

 whiting (G. merlangus) differs from both the preceding by the absence of barbels, 

 and is also lighter in colour than the cod, with the under-parts white and 



