EEPORT OF COMMISSIONER OF FISH AND FISHERIES. Ixxi 



ico is coQcerned, it is quite probable that whatever the degree of heat 

 to which they are subjected in the summer-season, they probably require 

 during their residence ia the sea a temperature as low, at least, as 

 about 40° Fahrenheit ; this inference being based upon the fact of their 

 restriction to more northern latitudes, in which this temperature is most 

 likely to be found. In considering the question of introducing the 

 California or other salmon into the tributaries of the Mississippi, the 

 inquiry was naturally suggested as to the temperatures of the Gulf of 

 Mexico, into which the salmon would pass in their outward journey, 

 and where they would probably remain. 



Application for information was accordingly made to Captain Pat- 

 terson, Superintendent of the Coast Survey, who kindly furnished copies 

 of records from the archives of the ofdce, (for details of these, see ap- 

 pendix,) from which we learn that in certain portions of the Gulf, 

 where the surfade-temperature was 77°, it was 50° at a depth of 230 

 fathoms, and at 420 to 790 fathoms it was noted at 35° and 36° Fahren- 

 heit, in the month of April. At another locality, with a surface-tem- 

 perature of 77i°, that at the bottom was 38°. At a depth of 1,133 

 fathoms, in a line from the mouth of the Mississippi to the Tortugas, 

 latitude 27° 16' and longitude 86° 57', the temperature at the bottom 

 was found to be 29°. On another line of soundings, between the mouth 

 of the Mississippi and the Tortugas, a temperature of 34° was found at 

 a depth of 896 fathoms ; while between Cuba and Florida 38° were noted 

 at 600 fathoms ; and on a line from Mobile to Key West the tempera- 

 ture at 190 fathoms was found to be 38°, that at the surface being 83°. 



Although it is probable that these indications, some of which were 

 perhaps made by the old-fashioned thermometers, may be somewhat 

 erroneous, yet there can be no question as to the occurrence in the Gulf 

 of Mexico of very deep water and of temperatures perfectly suited to 

 the abode of salmon of any species. Neither can there be any doubt of 

 the occurrence of suitable food in this same region. Therefore there 

 seems to be no reason to question that all the conditions needed for the 

 growth of this fish are to be met with in the Gulf of Mexico; and at 

 any rate we are warranted in making the experiment for the purpose 

 of determining the fact. 



5. — Tlie land-locked salmon {Salmo sebngo f). 



Certain bodies of water in Maine, especially the upper lakes of the 

 Saint Croix, Seed's Pond, near Ellsworth, Sebec Eiver and Pond, and the 

 Sebago Pond, are inhabited by a variety of the salmon in general habits 

 and appearance closely resembling the true sea-salmon but diiferiug in 

 size. Their average weight in most of the localities mentioned is from 2 

 to 4 or 5 pounds, sometimes, however, being taken weighing from 10 to 

 15 pounds. The Sebago fish is, however, much larger; the mature fish 

 averaging perhaps 6 to 8 pounds. A similar fish occurs also in the lakes 

 of Now Brunswick and perhaps of Nova Scotia. 



