44 DAHLBERG 



Sla parameter used in the Horst model, we can calculate larval 

 losses (Np) from 



Np = Lh X Lp (6) 



where Lh is total larval production or number of larvae hatched 

 (5.4775 X 10^) and Lp is percent reduction (Eq. 2). Thus Np is 

 5.4775 X 10"^ X 22.45% or 1.2297 x 10\ and the number of adults 



(NA)is 



Na =Sla X Np- 127,520 (7) 



Composition data in Table 2 indicate that Na would be 

 distributed among age classes as follows: age III, 0.757; age IV, 

 0.138; age V, 0.069; age VI, 0.014; age VII, 0.021; age VIII, 0.003. 



TABLE 2 



CALCULATING MEAN LIFETIME FECUNDITY AND SURVIVAL 

 FROM EGG TO ADULT FOR WALLEYES IN WESTERN LAKE 



ERIE, 1955-1970* 



* 



Total 1.0054 15,328.2 



Data are from Busch, Scholl, and Hartman (1975) and Wolfert (1969): 



Mean fecundity (F) = l^'^f^ = 15,246 



Mean lifetime fecundity = Mean generation time (G) X Mean fecundity 



= 3 X 15,328.2 = 45,984.6 

 = 5 X 15,328.2 = 76,641.0 

 2 

 Survivorship egg to adult (Sg^) = — 



F 



Sea = 4.3728 X 10~^ (1 per 22,869 eggs) for G of 3 



Sea = 2.6240 X 10~^ (1 per 38,110 eggs) for G of 5 



tCorrection for 86% maturity. 



