Age and growth of three species of tuna baitfish (genus: Spratelloides) in the tropical Indo‐Pacific

Sprafelloides grarilis (Temminck & Schlegel), S. delirarulus (Bennett) and S. lewisi (Wongratana) live generally less than 4 months. They lived more than 5 months at only three of 10 sites sampled. Growth varied seasonally in S. grocilis(Temminck & Schlegel) at two sites in the Solomon Islands and in S. clelicululus (Bennett) at Helix Reef, near Townsville, Australia. This variation in the growth rate of S. grucilis could not be related to specific environmental patterns, but that of S. delicurulus at Townsville might be temperature‐related. Instantaneous growth rates for all species were 0.4‐1.7 mm day ‐1 at an age of I month and the range of variation in growth rate was similar for all species. These rates declined to 0.1 mm day ‐1 at 3 months of age, which is the rate reported for other short‐lived clupeoids at the same age. The growth rates of fish from coral atoll and coastal lagoons were similar but barrier reef fish grew significantly faster. These results indicate that Sprarelloides have an extremely flexible growth pattern and that biological variation within a site can be as great as variation between sites.