] 16 



Fishery Bulletin 92(1), 1994 



sistent with the close relation with maximum size 

 found by Blaxter and Hunter (1982) for other 

 clupeoids. These authors also noted a latitudinal 

 effect; fish from lower latitudes spawned at a 

 smaller proportion of maximum size. 



Temperate clupeids (especially herrings, Clupea 

 spp.) show a great plasticity in the number and size 

 of eggs produced; many species show seasonal, and 

 inter-annual, as well as geographic, variation in 

 their reproductive outputs (Alheit, 1989; Jennings 

 and Beverton, 1991) reflecting energetic resources 

 and environmental conditions (Hay and Brett, 1988; 

 Henderson and Almatar, 1989). By comparison, the 

 tropical herring, H. quadrimaculatus, spawned 

 throughout the year and showed negligible tempo- 

 ral or spatial variation in fecundity, egg weight, or 

 inter-spawning interval. This indicates that egg 

 production was almost constant throughout the 



study period and suggests that adult food resources 

 and larval survival are predictable or relatively con- 

 stant (Sibly and Calow, 1983). 



In comparison to other species, S. delicatulus had 

 a higher relative fecundity that was also correlated 

 with HSI. Females in spawning condition also had 

 a higher HSI at Butaritari. Commercial CPUE was 

 highest at this site (Rawlinson et al., 1992) and S. 

 delicatulus spawned more, smaller eggs than at 

 other sites where relative fecundity was lower. 

 These data suggest that the fecundity of S. 

 delicatulus may be influenced by the amount of 

 energy stored in the liver. This energy store would 

 be important in a small multiple-spawning species; 

 it would enable the fish to continue spawning dur- 

 ing short periods of reduced food supply (Hay and 

 Brett, 1988). The length of the inter-spawning in- 

 terval has been shown experimentally to be related 



