316 BULLETIN OF THE BUREAU OF FISHERIES 



records suggest that its most active breeding season commences earlier to the west- 

 ward of Cape Cod, for he found them with ripe eggs at Woods Hole as early as March, 

 and many eggs in the plankton during the latter part of April. He first observed 

 the young on May 2 and found them in abundance throughout May and June. 

 Thus the season of active reproduction falls later and later from southwest to north- 

 east along the coast, as it does for many other animals. 



It is likely that with sufficient search the young would be found to be as widely 

 distributed as the adults over the open gulf, just as is the case in the Bay of Fundy, 

 but definite records of them from outside the 100-meter contour are still so few (as a 

 rule based on few individuals and invariably greatly outnumbered by larger sizes) 

 that the importance of coastwise and shoal banks waters as the breeding ground of 

 this species appears very clearly on the chart (fig. 88). Georges Bank in particular 

 serves as a nursery for Sagittse, witness the notable concentration of young Sagittse, 

 accompanied by a few larger (15 to 20 millimeters) specimens, over its western end on 

 May 17, 1920 (station 20128). Specimens ranging in size from 4 millimeters up- 

 wards abounded over a considerable area at about the same general locality in mid- 

 July, 1916 (stations 10347, 10348, and 10354). Slightly older specimens, 5 to 15 

 millimeters long, were also plentiful a few miles farther east on the 20th of the same 

 month in 1914 (about 430 per square meter at station 10216) and occurred sparingly 

 among the hosts of adults on the eastern part of the bank three days later (station 

 10224). Other notable catches of young S. elegans were made near Cape Sable 

 among a swarm of adults on July 25, 1914 (station 10230), and off Shelburne, Nova 

 Scotia, June 23, 1915 (about 200 small ones of 6 to 10 millimeters in a total of about 

 600 Sagittse of all sizes per square meter at station 10291). I may also mention 

 the presence of young S. elegans in Casco Bay in July, 1912, as an example of its 

 propagation close in to the land. Probably it is simply because the adults are more 

 abundant, not because physical conditions are more favorable to reproduction, that 

 more young Sagittse are produced within the 100-meter contour than over deeper 

 water. At any rate we can regard it as established that S. elegans is not only endemic 

 in the Gulf of Maine but breeds there in sufficient numbers to maintain the abundant 

 stock by local production, quite apart from any additions this may receive by im- 

 migration from other rich centers of reproduction. 



The general relationship of S. elegans to temperature and salinity, and its bathy- 

 metric status, is well established by Huntsman's (1919) exhaustive analysis, which 

 our Gulf of Maine data generally confirm. Broadly speaking, it is a creature of low 

 temperatures and comparatively low salinities, and wherever its range spreads out 

 from the coastal banks over parts of the oceanic basin high salinities act as a barrier 

 to its downward migrations. It is not likely, however, that this applies to any 

 part of the Gulf of Maine, unless it be to the deepest stratum of water in the extreme 

 southeastern corner. On the other hand, judging from the occurrence of S. elegans 

 in the Baltic, no part of the gulf, not even the larger estuaries, is too fresh for some 

 local variety of it to survive. Consequently, its local presence or absence in the 

 Gulf and its concentration at one or other level there can not be ascribed to the 

 precise salinity of the water, but its bathymetric distribution as it varies from 

 season to season is just what might be expected of any planktonic animal preferring 



