FISHERY BULLETIN; VOL. 87, NO. 4, 1989 



200 



180 



160 



i 140 



5 120 



P 100 



80 



60- 



Sexes combined 



TL = 63.2 + (16.7)R 



r=.9797 



n'130 



-I 1 1 I I 1 1 r- 



5 6 7 8 



-I 1 1 1—1 1 I 



9 10 11 12 



CENTRUM RADIUS (mm) 



Figure 2. — Relationship between vertebral centrum radius and total length (sexes combined) for 

 blacktip sharks captured in the Tampa Bay area of Florida. 



1.2 



1.0 



IT 



o 



2 



< 

 Z 

 CD -6 



< 



Z .4 



< 



RING 2 



I I I 

 M M 



RING 3 



range - 



12 



■T— r 



T 



M M 



MONTH 



Figure 3. — Mean monthly marginal increment correlated with month of capture for blacktip sharks with 1 , 2, 

 or 3 vertebral rings. Curves were fit by eye to best api)roximate the seasonal increase in marginal increment. 

 Translucent ring deposition appears to occur during December or January. 



848 



