654 



Fishery Bulletin 102(4) 



1 and 2 September 



1 and 2 September 



30 r 

 20 



10 





 30 



20 



10 



g- 30 

 lL 



20 



10 





 30 



20 



10 



L 



18:30 h 

 n = 5 



Ql 



i i i — i — i — i — i — t — i — i — i 



21:30h 

 n = 5 



tn= 



00:30 h 

 rt = 5 



hJ 



i i — i — 1_ 



_j — i — i — i 



03:30 h 

 n = 2 



r 



*<P^<&<&4PoPjP<&<& 



■<? $><W 



13 September 

 13 September 



18:30 h 

 n = 5 



Hliliri 



_i i i — i — i — i — i — i 



22:30 h 

 n=5 



M 



0= 



\? it nr t»° or A 1 ' <tr qP^^Tr 



'.c?^ 



Oocyte diameter (jim) 



Figure 3 



Frequency distributions for the oocyte diameters in mature ovaries of 

 Rhabdosargus sarba caught on 1-2 and 13 September 2001. The ovaries had 

 been preserved in formalin and their oocytes had been passed through a 

 125-^m sieve. The time of commencement of each 2-hour sampling interval 

 is shown, n = number offish used for oocyte diameter measurements. 



Batch fecundity, spawning frequency, 

 and potential annual fecundity 



The relationship between batch fecundity iBF) and 

 total length iTL) shown in Figure 8, and between batch 

 fecundity and somatic weight (W) are described by the 

 following equations: 



InBF = 5.00251nrL-17.557 



(P<0.001; r 2 =0.52, n = 30), 

 BF = 1997e 00105W 



(P<0.001; r 2 =0.55, n=30). 



The batch fecundities of R. sarba. predicted by the above 

 equations for fish with lengths of 180, 220. and 260 mm, 

 were ca. 4500, 7700. and 12,400, eggs, respectively, and 

 for fish with somatic weights of 100, 150, and 200 g were 

 ca. 5700, 9600, and 16,300 eggs, respectively. The average 

 daily prevalence of spawning during the spawning period 

 was 36.5^. Thus, during this period, individual females 

 spawned, on average, once every 2.7 days and therefore 

 about 45 times during the spawning season. The poten- 

 tial annual fecundities of female R. sarba with lengths 

 of 180, 220. and 260 mm were thus estimated to be ca. 

 204,300, 346,100, and 557,500 eggs, respectively. 



