— 146 — 



Within the regions investigated the greatest amount of productions occurs on the 

 British Atlantic coasts, at S. Iceland, the Fœroes and in the north-western part of the 

 North Sea, to a less extent in the western part of the Channel, the most northern part of 

 the Bay of Biscay and in the Skager Kak (here somewhat later in the year than on the 

 Atlantic coasts). On the other hand there is no spawning in the southern part of the 

 North Sea (nor in the Kattegat, Belt Sea or Baltic). 

 The boundaries for the spawning are: 



northern limit: off N. W. and S.E. Iceland; 



southern limit: southern part of the Bay of Biscay; 



minimum temperature: ca. 6° — 7°; 



maximum temperature: ca. 10°; 



principal spawning time: spring, especially at the end. 



14. Blue ling (Molva hyrkelange [Walb.]) 

 Both the northern and southern boundaries for this species fall within the regions 

 investigated. Its requirements for great depths (min. ca. 5—600 meters), high salinities 

 (min. ca. 35.15- 20 "/oo) and temperatures exclude it from spawning to the N. and E. of 

 the Submarine Kidge between Greenland— Iceland — Fseroes (thus the whole Norwegian 

 Sea) \ also in the North Sea and the Channel. It spawns in quantities in the Atlantic 

 over the whole distance from off W. Iceland to the large Outer Bank west of Ireland, in 

 greatest quantities W. of the Fseroes and W. of the northernmost parts of the British 

 Isles. On the other hand no production takes place in the southernmost parts of the 

 regions investigated (Bay of Biscay, the waters S. and W. of Ireland); here the tempera- 

 tures and salinities are apparently too high. 

 The boundaries for the spawning are : 



northern limit: the waters N. W. of Iceland (including these); 



southern limit: large Outer Bank W. of Ireland; 



minimum temperature: ca.5°— 6°; 



maximum temperature: ca. 8° ; 



principal spawning time: spring. 



15. Mediterranean ling {Molva elongata Risso) 

 Only the northern boundary lies within the regions investigated. On account of its 

 requirement for great depths and high salinities (min. ca. 35-50 "/oo) and temperatures this 

 species is excluded from spawning over the greater part of these regions, and this only 

 occurs in the Atlantic south of the large Outer Bank to the west of Ireland and in the 

 Bay of Biscay, in deep water of about 1000 meters. The evidence that this species, hitherto 

 only known from the Mediterranean, occurs and reproduces in the southernmost part of 

 our deep-water Atlantic region is of great interest; in this region the temperature and 

 salinity are so unusually high that they recall the conditions in the Mediterranean (cf. the 

 spawning of the eel and occurrence of its larva Leptocephalus brevirostris which was also 



' Acoordiug- to friendly information from Dr. Joiian H.iort the blue ling reproduces however in a 

 few of the deep Norwegian fjords, where the hydrographical conditions recall those in the Atlantic. 

 There is also a very little spawning in the deepest parts of the Skager Rak. 



