FISHF:RV BILLETIN: VOL. Ki. NO. .S 



, Y = 244 40{X)-33I.57 

 n-23 r = .83 



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UJ 



o 



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 CD 



2000 r 



^ 1000 



y^» • Y = 329.44(X)-3I4.36 



n = 23 r=.83 

 i_/^M I 1 1 1 1 1 1- 



2000 



1000 



JULY 6-13 



i/- 



Y = l44.42{X) + 249.65 



n=l4 r = .6l 

 I I I I I 



3456789 10 



OVARY- FREE FEMALE WEIGHT(g) 



FiGi'RE 4. -Relation between batch fecunditv' (no. of eggs in the 

 most advanced size class) and ovary-free female body weight for 

 Atlantic silversides captured on four occasions during the 1977 

 breeding season in Essex Bay, MA. 



UJ x: 



"2 jQ 



< 3 



I- 

 o 



o 



UJ 



000 



500 







^ 1500 



1000 



5 5 



q: _ 



q: ct 500 



UJ ^ 







g IS" 100 



D 



" E3 i 



B 



k23) (23) (29) (17) 

 1 1 



MAY 



JUNE 



JULY 



Batch fecundity as estimated above assumes that 

 the number of eggs in the most advanced mode is not 

 reduced by atresia as they grow and are eventually 

 shed. I noted few eggs which appeared to be atretic 

 or in a process of resorption (except near the very 

 end of the breeding season) and females which had 

 recently spawned usually contained few. if any, 

 residual ripe eggs. Similar observations were 

 reported by Clark (1925) for the atherinid Leuresthes 

 t£nuis. Moreover, if some eggs cease growing and 

 are resorbed before reaching maturity, there should 



Figure 5. -Relative fecundity (no. eggs/g ovary-free female body 

 weight) for Atlantic silversides captured on four (x-casions during 

 the 1977 breeding season in Essex Bay. MA. The horizontal lines 

 represent means, the vertical lines represent one standard devia- 

 tion, and the rectangles represent 95% C.L. Sample sizes are in 

 parentheses. All fish were spent on 26 July. A) ToUil number of 

 eggs. B) Number of recruitment eggs (recruitment fecundity)- C) 

 Number of mature eggs (batch fecundity). 



be a negative correlation between batch size and the 

 mean diameter of eggs in the batch (i.e., no. batch 

 eggs/g ovary-free body weight should generally be 



336 



