124 



Fishery Bulletin 91(1), 1993 



life-history stages of these two 

 menhadens suggest that Atlan- 

 tic menhaden reaches a size- 

 threshold at a smaller size than 

 gulf menhaden. For regression 

 lines that described the length- 

 weight relationship for Atlantic 



menhaden >10mmSL and gulf menhaden >12mmSL, there were no differ- 

 ences between slopes or intercepts. For Atlantic menhaden <10 mmSL and 

 gulf menhaden <12 mmSL, there were no differences in slopes between the 

 two species, although their intercepts differed. Beginning at the size- 

 threshold in both species (>10mmSL for Atlantic menhaden, >12mmSL for 

 gulf menhaden), there is a larger change in weight in relation to a given 

 change in length, reflecting morphogenic changes. 



100 

 80 

 60 

 40 

 20 

 



100 

 80 

 60 

 40 

 20 

 



20° C 



x 



01 2345678 



lOOf--,. 

 80- 

 60- 

 40 

 20 

 



_i_ 



1 2 3 4 5 6 7 8 



DAYS PAST FIRST FEEDING 



Figure 3 



Time to starvation of unfed 

 Brevoortia tyrannus !•) and B. 

 patronus ( ) in relation to tem- 

 perature. Approximately 25 larvae 

 were used at each experimental 

 temperature. N denotes number of 

 replicates. 



Discussion 



Egg size and its influence on early-life-history characteristics have received 

 considerable attention. My results, in general, are in accord with other 

 studies of diverse fishes and other organisms. Larger eggs are positively 

 correlated with size of larvae at hatching, yolk reserves, resistance to star- 

 vation, and size-at-first-feeding, e.g., Blaxter & Hempel 1963 (clupeoid stocks), 

 Crump 1984 (amphibia), Wallace & Aasjord 1984 (salmonids), Knutsen & 



