FISHERY BULLETIN: VOL. 84, NO. 3 



ESTUARY OF THE PATOS LAGOON 



32?- 



S. LourtnfO 

 do Su 



PATOS 



LAGOON 



RIO GRANDE 

 do SUL 



»* 



> v 



53< 



52° 



5I ( 



Figure 1.— Coastal lagoon system of southern Brasil (A) and the study area (B). 



type of deposit (opaque or hyaline) on the otolith 

 margin and the number of hyaline zones were re- 

 corded for each otolith. Back-calculation was done 

 over the surface, the total length of the otolith (Co) 

 and the length between the nucleus and each hya- 

 line zone (ci) (Fig. 2) were measured with an ocular 

 micrometer. The term nucleus used here refers to 

 the central area of the otolith limited by the first 

 zone (Jearld 1983). 



Growth curves for males and females were cal- 

 culated using the mean lengths for year class. The 

 parameters of the von Bertalanffy growth equation 

 were determined: 



Lt = L m [1 - e-^'-W] 



(1) 



where Lt is the total length at time t, L M is the 

 maximum attainable size, K is the growth coeffi- 



680 



