312 BULLETIN OF THE BUREAU OF FISHERIES 



be a degree or two higher. Thus, practically the entire production of rosefish takes 

 place in water colder than 47°, and apparently this upper temperature limit is a 

 rather definite one, for there is some evidence that at breeding time the adult fish 

 move out of Passamaquoddy Bay (which is then but a few degrees warmer) into 

 deeper and cooler water in the open Bay of Fundy. 



Turning to other seas we find rosefish breeding in 39° to 42° in the Gulf of 

 St. Lawrence, in water at least as warm as 39° to 40° on the outer edge of the 

 Grand Banks, 72 and in 37° to 39° or warmer off southern Newfoundland. 73 The 

 hosts of rosefish fry to be found all over the Norwegian Sea are likewise produced 

 in comparatively warm water (39° to 43°), as Hjort has emphasized. In fact it is 

 doubtful whether Sebastes breeds at temperatures lower than 35° to 36° anywhere, 

 for although it grows to a large size off west Greenland, Jensen states that females 

 with large eggs and the early larval stages are both unknown there, but that the 

 local stock is all produced in the Atlantic, reaching Greenlandic waters as immigrants 

 with the current while still young. However, until the temperature at which it 

 breeds is definitely established for the outer coast of Nova Scotia, where this would 

 depend upon the precise depth at which the fish are living, the minimum tempera- 

 ture at which Sebastes can reproduce must remain in doubt. 



The salinity in which rosefish breed is as definitely limited in one direction as 

 is the temperature, if not in the other, for its young are for the most part produced 

 in salinities upwards of 32 per mille. 



The larvse are about 6 mm. long at hatching (fig. 144), with the yolk mostly 

 absorbed, the mouth already formed, and the first traces of the caudal rays already 

 visible. At a length of 12 mm. (fig. 146) the dorsal and anal fin rays appear, 

 the ventrals are visible, and the head spines are already prominent, while fry of 20 

 mm. (fig. 147) show most of the diagnostic characters of the adult except that 

 head and eye are relatively larger. The red color is not developed until the little 

 fishes are about to take to bottom, but all but the very youngest larvse are easily 

 recognizable by their large spiny heads, large eyes, short tapering bodies, very 

 short digestive tract, and the presence of two rows of post anal pigment cells, a 

 dorsal and a ventral. Nothing definite is known of the rate of growth of the older 

 rosefish. 



Commercial importance. — Although a very common fish and an excellent one 

 on the table, as we ourselves can bear witness, as well as attractive in appearance, 

 there is so little market for it that but a small part of the fish caught are brought 

 in (p. 307), and what little was landed in 1919 (54,095 pounds) was valued at only 

 two to three cents a pound. Every kind of fishing gear used in deep water catches 

 rosefish. 



" Murray and Hjort. The Depths of the Ocean, 1912, p. 110. London. 



" Dannevig. Canadian Fisheries Expedition, 1914-15 (1919), Department of the Naval Service, p. 12. 



