AGE DETERMINATION OF AMERICAN 6HAD 



169 



FiGUBE 8. — Scale from 6-year-old marked shad spawning for the third time. 



for the second time had first spawned in 1957, and 

 those spawning for the third time had first 

 spawned in 1956. 



Age of marked shad, as determined from scale 

 readings, was in agreement with known age estab- 

 lished by marking. These findings validate the 

 use of annuli and spawning marks for determining 

 total age of shad. 



LITERATURE CITED 



Barney, R. L. 



1925. A continuation of Borodin's .scale method of 

 use determination of Conecticut River shad. In 

 Mitchell, P. II., A report of investiRations con- 

 cerning shad in the rivers of Connecticut, Part III, 

 pp. 52-60. Hartford, Conn. 



Borodin, N. A. 



1925. Age of shad Alsoa sapidissima (Wilson), as 

 determined by the scales. In Mitchell, P. H., A 

 report of investigations concerning shad in the 

 rivers of Connecticut, Part II, pp. 46-51. Hartford, 

 Conn. 



Cable, Louella E. 



1956. Validity of age determination from scales, and 

 growth of marked Lake Michigan lake trout. 

 U.S. Fish and Wildlife Service, Fishery Bulletin, 

 No. 107, vol. 57, pp. 1-59. 

 Cating. James P. 



1953. Determining age of Atlantic shad from their 

 scales. U.S. Fish and Wildlife Service, Fishery 

 Bulletin, No. 85, vol. 54, pp. 187-199. 

 Code, SIark R. 



1950. Cutthroat trout without dorsal fins. Progres- 

 sive Fi.sh Culturist, vol. 12 (2) : pp. 85-86. 

 Greeley, John R. 



1937. Fishes of the area with annotated list. In New 

 York ('onservation Department : A biological sur- 

 vey of the lower Hudson waterslunl; supplemental 

 to twenty-sixth annual report, 1936. Part II, pp. 

 4.5-103. .1. 15. Lyon Company, Albany, N.Y. 

 (iReenbank. Joii.n, and I). John ()"1)onnei.l. 



1950. Hydraulic presses for making impressions on 

 fish scales. American Fisheries Society, Trans- 

 actions, vol. 78 (194,S), pp. 32-37. 

 H.wimer. Ralph Curtis. 



1942. The homing instinct of the Chesiipeake Bay 

 shad Aluna saiiidissiiiui (Wilson), as revealed by a 



