The fecundity and egg production of four species of small clupeoid, the anchovies Encrasicholina devisi, E. heterolobus, and the sprats Spratelloides delicatulus and S. lewisi, were examined at three sites in the Solomon Islands, tropical South Pacific. All species are multiple spawners and batch fecundity ranged between 500 and 1900 eggs per spawning, being significantly lower in the two sprat species than in the co-occurring anchovies. The fecundity of all species varied between sites, but not markedly between seasons. In Encrasicholina, fecundity was positively correlated with water temperature and zooplankton density, whereas in Spratelloides it was correlated with the hepatosomatic index. These results suggest that the fecundity of Encrasicholina is directly related to food intake, but Spratelloides probably depend on energy reserves in the liver for spawning. Egg volume differed between species and between sites for each species. Egg volume was inversely related to fecundity. Both species of Spratelloides had fewer, larger eggs than the similar-sized Encrasicholina species, which had much higher batch fecundity. This may be a consequence of lower or more predictable egg mortality that results from their benthic-spawning habits. Egg dry weight varied between sites for all species except E. devisi, but the pattern differed for each species. For Spratelloides, egg weight varied in a similar manner to egg volume. However, at any site the egg weights of all species were similar and showed little seasonal variation. These species are fast growing and short-lived (4-8 months); they spawn at 2 to 4 months of age and spawn, on average, every 2 to 8 days during their reproductive lifespan of up to 4 months. Differences within species in these reproductive parameters made monthly reproductive output highly variable, but with a similar mean life-time egg production at each site. The estimated daily population egg production of populations of each species varied with stock size (estimated from catch per unit effort). Daily egg production was correlated in E. devisi and E. heterolobus at Munda and Vona Vona, which suggests that similar factors affected egg production at these sites. However, there was no direct relationship between egg production and subsequent recruitment, except for S. lewisi at Tulagi. These results indicate that even for short-lived, fast-growing tropical species that recruit within 2 months of hatching, recruitment is more strongly influenced by factors such as variation in egg and larval survival than parental stock size.
