NELSON and AHRENHOLZ: CHARACTERISTICS OF GULF MENHADEN 



Figure 1— Mean length of gulf menhaden at 

 ages 1-3 taken from commercial landing sam- 

 ples (April- June), 1964-78. 



E 

 E 



I 

 I- 



O 



z 



LU 



—I 



rr 

 O 



Li. 



< 



LU 



250r 



200 



150 



100 



of 



J I 



J I I L 



J L 



1964 65 66 67 68 69 70 71 72 73 74 75 76 77 78 



YEAR 



pletely through the fishery were used in the growth 

 computations (Table 2). The von Bertalanffy growth- 

 in length equation 



l t = Loo(l - e 



■W-L 



') 



(1) 



where l t = fork length (mm) at time t (years), 

 Leo = theoretical length at t = infinity 



(asymptote), 

 K = growth coefficient, 

 t = theoretical age when length = 



was fitted to the data by the computer program 

 BGC3 (Abramson 1971). Although the data points 

 appear stepped between whole age units, they are 

 reasonably well described by the fitted curve (Fig. 2). 



Table 2.— Mean length and number of 

 fish sampled at age from 1963 to 1974 

 year classes of gulf menhaden. 



E 

 E 



X 

 t- 



a 



z 



LU 



_) 



cr 

 O 



LL 



AGE IN YEARS 



Figure 2— Von Bertalanffy growth curve fitted to average length at age data for gulf menhaden 

 sampled from commercial landings, 1963-74 year classes. 



313 



