832 



Fishery Bulletin 101(4) 



16 



15 



14 



13 



12 - 



^ 11 



1 5 



O 



5 16 

 15 

 14 



Prediclion Inlerval (2 SD) 



Confidence Intenal (95%) 



Ln Fecundity = -6.86 + 3.42 (Ln TL) 

 r^ = 0.W3, F = 527.2. df= 129 



50 



5.75 



6.00 

 Ln Total length 



6-25 



6.50 



13 



12 



5.0 



5.5 



6.0 



6.5 



Ln Body weight 



70 



7.5 



80 



Figure 9 



Regression of the natural log (Ln) transformation of individual fecundity on 

 total length (A) and body weight (B) for striped mullet combined data, 1998 to 

 2000, from South Carolina estuaries, n (number offish in sample) = 129. 



350 jjm. The vitellogenic activity in these ovaries was still 

 in the primary and secondary stages. These specimens 

 could not be used for fecundity counts because not all 

 of the oocytes destined for that year's spawning batch 

 had developed enough to be separable from the smaller 

 oocytes that would not develop. Once the developing 

 oocytes reached a size of 400 ^m or larger, they became 

 more uniform in size and in appearance and it was obvi- 

 ous which oocytes would constitute that year's spawn. At 

 that point, fecundity could be determined more accurately 

 because all the oocytes to be counted were significantly 

 and equally larger. This point in particular is important 

 in that it makes fecundity estimates from nonhydrated oo- 

 cytes more accurate for isochronal spawning fishes, such 

 as striped mullet. Fecundity estimates made in fishes that 

 are batch-spawners should only be made from hydrated 

 oocytes because of the presence of multiple developmental 

 stages (Hunter and Macewicz, 1985). The presence of dif- 

 ferent vitellogenic stages in the ovary of a repeat-spawn- 

 ing fish makes it necessary to determine individual batch 

 fecundity and spawning frequency before any estimate 



of annual fecundity can be made. In isochronal spawn- 

 ing fishes, such as striped mullet, this process is made 

 simpler by the fact that oocytes mature at a similar rate 

 (Greeley et al., 1987). During early vitellogenesis (180 ^m 

 to 350 fjm), there is a higher degree of variability in the 

 rate of development and a range of developmental stages 

 would be present from the presence of precortical alveoli 

 through secondary and tertiary vitellogenesis (Render et 

 al., 1995). Estimating numbers of oocytes (uniform in an 

 individual but varying in size because of season) during 

 this stage would naturally make oocyte density and oocyte- 

 size relationships inconsistent. This could possibly be cor- 

 rected by using some timing factor such as month during 

 the spawning season. The present study did demonstrate 

 an inverse relationship between oocyte density and oocyte 

 diameter When month of capture was taken into consider- 

 ation, oocyte density decreased with increasing oocyte size 

 as the spawning season progressed. 



In conclusion there were several biological aspects of 

 striped mullet reproduction demonstrated in this study. 

 Fecundity levels in striped mullet increased with total 



