236 BULLETIN OF THE BUREAU OF FISHERIES 



instance, is the case in the fjords and along the coast of Norway (Sars, 1903; Farran, 

 1910), between Iceland and the Faroes (Wolfenden, 1904), in the Faroe channel, in 

 the Gulf of St. Lawrence, and along the outer coast of Nova Scotia (Willey, 1919). 

 In the northeastern Atlantic reports of it at the surface have usually been based 

 on immature specimens; but this rule does not apply to the Gulf of Maine, Willey 

 (1922) having found it in the breeding state close to the surface near St. Andrews. 

 Euchseta necessarily inhabits a somewhat shoaler zone in the gulf (with its lower 

 limit set at about 300 meters by the topography of the bottom) than in the 

 Norwegian sea and between Iceland and the Faroes, where it occurs chiefly below 

 200 to 300 meters, and down to 1,000 meters. 



Breeding. — Our failure to find E. norvegica at any time in the eastern or northern 

 channels (we have one record of it on Browns Bank, June 24, 1915, station 10296) and 

 the fact that its seasonal fluctuations in abundance along the continental shelf are 

 not reflected within the gulf are evidence that the maintenance of the Gulf of Maine 

 stock depends more on local reproduction than on immigration. Were the opposite 

 true, we would expect to find it in the two channels, these being the entrances for 

 visitors from the mid-depths offshore, or from the east and north, and most plentiful 

 within the gulf at the season when it is most plentiful outside. Adult females with 

 egg clusters attached are familiar objects in the deeper Gulf of Maine tows, while 

 Willey (1921) has found adidt males with spermatophores as well as egg-bearing 

 females and immatures of both sexes at St. Andrews. 



Willey's specimens were taken in February, and since females with egg sacs 

 were noted in the Albatross tows on March 3, 1920 (station 20055), and outside the 

 continental edge off Shelburne, Nova Scotia, on the 19th (Station 20077), while 

 most of the summer catches of the species have contained them, E. norvegica evi- 

 dently spawns throughout the year in the Gulf of Maine. The vertical distribution 

 of the species proves that reproduction takes place almost entirely below 100 meters, 

 though occasional individuals in breeding condition may occur at the surface. 



Relationship to temperature and salinity. — The tendency of this species to keep to 

 deep water makes it easy to establish the physical conditions under which it lives in the 

 gulf. 



The great majority of the captures have been in comparatively high salinities 

 (33 to 34 per mille) and from temperatures lower than 10°, the quantitative occurrence 

 of the species pointing to the higher salinity and to a temperature lower than 8° as 

 its optimum. Such of the Gulf of Maine stock as lives below 150 meters inhabits a 

 zone in which the yearly range of temperature is narrow — for the most part between 

 6 and 4°. However, its presence at the surface proves that it can survive a brief 

 visit in water as warm as 19 to 20° (stations 10254 and 10256, western basin, August 

 22 and 23, 1914). On the other hand, the wide Arctic distribution of E. norvegica 

 makes it unlikely that the temperature is ever unfavorably low for it in the Gulf of 

 Maine, which is corroborated by its presence near the surface at St. Andrews during 

 the coldest season (Willey, 1921). The failure of this species to work farther inward 

 toward the Baltic 31 than the Skager-Eak makes it probable that salinities lower than 



ai One record (rom the Kattegat is mentioned by Farran (1910). 



