310 BULLETIN OF THE BUREAU OF FISHERIES 



breeding ground. The rosefish reproduces considerably farther west than this on 

 the outer edge of the continental shelf, for thousands of young fry, as well as adults 

 full of spawn, were collected in 100 to ISO fathoms off the southern coast of New 

 England during the early years of the United States Bureau of Fisheries. 



Although we have found rosefish larvae so universal over the offshore parts of 

 the Gulf, the notable centers of abundance have all been located within a few 

 miles, one side or the other, of the 50-fathom contour, whether it be the general 

 slope, the boundary of an offshore bank, or some isolated sink, in which locations 

 they may locally rival the swarms encountered by Schmidt between Iceland and 

 the Faroes. 71 As examples we may mention catches of several hundred off Cape 

 Elizabeth on July 29, 1912; near Cape Sable on August 11, 1914; near Cashes 

 Ledge on August 10, 1913, and again on September 1, 1915; in the sink off Glou- 

 cester on August 9, 1913; and on Platts Bank on August 7, 1912. Outside the 

 100-fathom contour, on the contrary, the records are usually based on occasional 

 specimens only, and it is only in the northeastern part of the Gulf that they appear 

 with any frequency over the deepest water (fig. 142). We have seldom taken 

 young Sebastes in the western basin, though we have towed there frequently and 

 at all seasons, and never in the deep southeastern trough of the Gulf nor in the 

 eastern channel. All this suggests that the chief production of rosefish in the Gulf 

 of Maine occurs at about 50 fathoms depth, which probably applies equally to the 

 Bay of Fundy, where, according to Huntsman (1922a, p. 16), "the spawning indi- 

 viduals at least move out into deep water." However, the presence of larvae no 

 longer than 6.5 to 10 mm. — that is, new born — at every station where the species has 

 been represented in our tow nettings by more than one or two examples, shows that 

 some rosefish breed in the deepest parts of the Gulf, though it does not necessarily 

 follow that the fish are on bottom there. 



Apparently the rosefish never breeds in less than 20 to 30 fathoms west or 

 south of Penobscot Bay. About Mount Desert, however, and further east along 

 the coast of Maine, it may perhaps do so in shoal water. According to the European 

 observations rosefish larvae live close to the surface until they attain a length of 

 60 mm. (nearly 2)4, inches), and, similarly, young larva? (S to 10 mm.) occasionally 

 occur in great numbers on the surface in the Gulf of Maine, but most of our records 

 are from 20 fathoms or deeper. The fact that we have never caught one larger 

 than 21 mm. in our tow nets, whereas fry of 1 J^ to 3 inches are plentiful on bottom 

 in the Bay of Fundy and have been trawled in abundance in deep water off southern 

 New England (p. 310), suggests that they seek the ground at an earlier age in the 

 Gulf of Maine than on the other side of the Atlantic. 



The temperature in which rosefish breed in the Gulf of Maine is easily estab- 

 lished with the spawning period so brief (p. 30S) and with the adult fish summering 

 below the zone most subject to seasonal warming. Thirty-seven to thirty-nine 

 degrees may be set as the lower limit, for by the time breeding is well under way — 

 say late in June or early July — there is no water colder than this in the Gulf. On 

 the other hand the temperature at the 20-fathom level rises only to 46° or 48° by 

 the end of August, except locally in regions of active vertical mixing, where it may 



" Schmidt. Skrifter Udgivne of Kommissionen (or Havunderspgelser, Xr. 1, 1901, p. 46. 



