302 MARKETABLE BRITISH MARINE FISHES 



breeze is one of the most curious and beautiful in nature. The 

 little rocklings, or mackerel midges as they are called, dart 

 away from the boat's advancing cutwater through the teeming 

 Xoctiluca, making lines of light in their tracks, so that it almost 

 seems as though the bows of the boat were constantly giving 

 out rays of light, or as though the vessel were sailing through 

 an enchanted sea. 



After the rocklings grow to li inches long they begin to 

 lose their brilliant, silvery dress, and become dull brown. Then 

 they leave the surface of the sea, and are found hiding away 

 under stones on the shore, between tide-marks, or on the bottom 

 in shallow water. The spots of the three-bearded kind do not 

 appear until it is several inches in length. 



The Tusk, or Torsk (Brosmius brosme). 



Distinguishing Characters. Body cylindrical. The skin is 

 thick and tough, over the fins as well as the body ; the vent is 

 rather far back, the ventral fin commencing beneath about the 

 thirty-fifth dorsal ray. Scales minute. Colour on the back 

 greyish, tinged with yellow, which colour is more pronounced on 

 the margins of the fins and gives the fish a very characteristic 

 appearance. Usual length about 18 inches, but the fish grows 

 to over 3 feet. 



Habitat. From Spitzbergen to the latitude of Grimsby, 

 abundant in the Shetlands and Faroe Islands, also on the 

 American coast as far south as Cape Cod. Its range extends 

 to very deep water. 



Food. Chiefly crustaceans and smaller fish. 



Breeding. Of the number examined for Dr. Fulton thirty- 

 nine were females, thirty-five males ; and he calculated the 

 number of eggs in a specimen 34 inches long, 15 Ibs. 5i oz. in 

 weight, at 2,283,000. Ripe females were only observed at Peter- 

 head and Lerwick in May and June. In the endeavours to 

 procure fertilised eggs it was noticed that the testes or soft roes 

 were very small in comparison with the ovaries or hard roes. 

 This case resembles somewhat that of the sole. Mr. Duthie 

 the Assistant Fishery Officer at Lerwick, informed Dr. Fulton 

 that the males landed were all immature, but when advised to 



