150 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

 37. SALMO OQUASSA, Girard. 



BLUE-BACK LAKE-TROUT ; THE OQUASSA TROUT. 



Syx. — Salmo oqnasm, Ged. Proc. Bost. Soc. Nut. Hist., vol. iv, p. 262. (Read 

 before tlie society October 20, 1852.) 



Sp. Ch. — [Condensed from Dr. Girard's description, and the examin- 

 ation of eight specimens,] Length (of full grown adult ?) from 8 to 10 

 inches. Body subfusitbrm, slender, gracefiiL Head proportionally 

 small, conical. Mouth smaller than in iS. fonti nails, from which it 

 also dilfers in the structure of the opercular apparatus. Fins 

 placed in the same relative positions as the latter, but larger, excepting 

 the adipose, which is considerably smaller. Margin of the caudal some- 

 what forked and undulated. Scales nuich like those of the brook-trout, 

 but larger. Lateral line similar in botli species. 



Colors. — A bluish tint extends all along the back from the head to 

 the tail, so that when seen from above the fish appears entirely blue. 

 Sides ami abdomen silvery-white in the female, and of a deep reddish- 

 orange in the male, spotted in both sexes with tlie same hue as the 

 abdomen. Dorsal and caudal fins brownish-blue, bordered with pale- 

 orange in the male ; the pectorals, ventral s, and anal of a fiery-orange, 

 biackish-blue at their bases, and margined with white. 



Hab. — Mooseineguntic Lake, Kenebago River, Lake Oquassa, Maine. 



According to Dr. Girard tliis is a lake species, of great delicacy and 

 beauty. It is found on Lake Moosemeguntic, making its appearance 

 from the depths about October 10, and, coming near the shore, ascends 

 the Kenebago River in shoals. Half a mile from its mouth the Kene- 

 bago receives the outlet of Lake Oquassa. The trout there leaves the 

 Kenebago and enters Oquassa Lake, wliere its voyage comes to a close. 

 After the middle of November it returns to Moosemeguntic, and is not 

 again seen till the following year. It is known to the residents of that 

 region as the blue-bacli. 



Dr. Girard adds the following remark: " The flesh of the fish is highly 

 flavored and more delicate than the brook-trouts in Europe and Ameri(!a. 

 It resembles that of *S'. ninhla, of the Swiss Lakes, both in the peculiarity 

 of its habits and its delicacy, ^almo nmhla is a lake-trout, an inhabit- 

 ant of the deep, making its appearance near shores January and Febru- 

 ary' to spawn, and never ascending the brooks or rivers, tributaries of 

 the lakes. 



Diagnosis. — From S. gloreri, b}' lacking black spots ; by its smaller 

 scales. From iS. fontinalis, or the common brook-trout, it can be distin- 

 guished by the uniform color of the back; its unspotted fins, (tail in- 

 cluded;) slightly larger scales; small, conical head; slender body; small 

 size of the light spats along the flanks, and by the colors, as given. 



