284 
BULLETIN OF THE BUREAU OF FISHERIES 
Riiincalanus nasutus Giesbreclit 
This is a typically oceanic species, warm temperate in its relationship to tem- 
perature, and wide ranging in all three great oceans. It has been recorded widely 
in the eastern Pacific (Giesbrecht, 1892; Esterly, 1905), in the Malay Archipelago 
(Andrew Scott, 1909 52 ), at several localities in the northern part of the Indian 
Ocean (Thompson and Scott, 1903; Wolfenden, 1905), and at the mouth of the 
Red Sea (A. Scott, 1902). In the Atlantic it is known from latitude 35° 10' S., in the 
south (Wolfenden, 1911), to Denmark Strait, the sea south of Iceland, the neighbor- 
hood of the Faroes, the Norwegian sea, and the northern part of the North Sea in 
the north. Farran (1910) and With (1915), who have summarized what is known 
of its distribution, have both pointed out that in the northeastern part of its area 
of occurrence its range is coterminous with the ebbings and flowings of the highly 
saline and comparatively warm waters of the Atlantic current. This applies equally 
off the Atlantic seaboard of North America, where it has been taken outside the 
continental edge off Chesapeake Bay, off Delaware Bay, and off New York in the 
summer of 1913 (stations 10064, 10071, and 10076); off Georges Bank, Juljq 1914 
(stations 10218 and 10220); off Cape Sable; off Sable Island; and off the mouth 
of the Laurentian Channel between the Nova Scotian and Newfoundland Banks, 
June-July, 1915 (Willey, 1919, 7 stations); also east of the Grand Banks by the 
Michael Sars (Murray and Hjort, 1912, p. 654). 
Within the Gulf of Maine R. nasutus has much the same status as its close rela- 
tive R. cornutus (p. 283), there being 10 records, all but one of them in the peripheral 
belt, around which they are scattered from Browns Bank and off Yarmouth, Nova 
Scotia, to off the tip of Cape Cod, a distribution quite typical for any planktonic 
animal reaching the gulf as an immigrant from the Atlantic basin and unable to 
survive long or to reproduce itself there. 
The geographic locations of the stations where R. nasutus was taken (fig. 72) 
are also interesting in pointing to the upper 100 meters or so as the stratum in which 
it enters, for if it drifted into the gulf in the underlying waters it might be expected 
to follow the branches of the basin, as do the bathypelagic chaetognaths Eukrohnia 
hamata (p. 328) and Sagitta maxima (p. 324), instead of circling along and inside 
the 100-meter contour. 
Farran (1910) and With (1915) have described the vertical range of this species 
as uniform from the surface down to 1,800 meters. Most of the captures listed by 
Willey (1919) in Canadian waters were in open vertical hauls from depths of 200 to 
375 meters; once on the surface. The Michael Sars record just mentioned was in a 
closing net at 950 to 525 meters. The captures within the Gulf of Maine have all 
been in open nets — horizontal (station 10225) or vertical — from depths of from 48-0 
down to 240-0 meters; none from the surface. 
The Gulf of Maine records for R. nasutus are for the months of March (three), 
April (two), May (four), and one for July; 53 but with so few records it is questionable 
whether this seasonal periodocity actually means that R. nasutus is more apt to enter 
* J He uses the name Rhincalanus gigas Brady for it. 
83 In addition to the stations listed in the tables, (p. 297), R. nasutus was taken at station 10225 on July 23, 1914, and at 
stations 10272 and 10273 on May 10, 1915. 
