AGE OF ATLANTIC SHAD FROM SCALES 



197 



Fiqure 11. — Scale frc.iii the same female shad as scale shown in figure 12, but taken .~>l days later. The fish was caught 

 in the Atlantic Ocean off the coast of Massachusetts after Leaving the river. Note the ragged periphery cause] 

 by absorption (luring the slay in fresh water, and the extent to which the edge was absorbed. The fifth annulus 

 can he seen in only a few places. Compare this scale with th le shown In figure 12. 



of age usually shows absorption to or over the 

 fifth annulus, as illustrated in figure LO; scales 

 from shad that are spawning for the first time at 

 ;") years of age are usually absorbed back to the 

 fourth annulus; scales from shad spawning for 

 the first lime at 4 years are usually absorbed back 

 about half way toward t he third annulus as shown 

 in figure 6; and a shad coming back to spawn at 



•". years of age usually has scales absorbed one- 

 fourth to one-half the distance to the second an- 

 nulus. During any particular spawning run, the 

 anion nl of absorption depends on the time I he fish 

 spends in fresh water. If the scales are from shad 

 taken just before they enter fresh water, little or 

 no absorption id' the previous year's growth should 

 be found. 



