OTOLITH AGE VALIDATION AND GROWTH-RATE VARIATION IN FLYINGFISH 'HIRUNDICHTHYS-AFFINIS) FROM THE EASTERN CARIBBEAN

A study of otolith aging and growth-rate variation in the flyingfish H irundichthys affinis (Gunther) was conducted in the eastern Caribbean (10-16-degrees-N; 58-62-degrees-W) in 1987-1989. Daily otolith-increme nt formation was validated in laboratory-reared larvae, confirming the usefulness of otolith-increment counts for age determination of H. af finis juveniles (<150 mm fork length, FL). A mark-recapture programme to validate increment formation in wild adults was unsuccessful due to tetracycline-linked mortality and insufficient tetracycline uptake in slow-growing adult otoliths. A von Bertalanffy growth curve fitted to juvenile size-at-age data gave preliminary growth-curve parameters of t0 = 2.85 d and k = 0.00854 on a daily basis, with an asymptotic leng th, L(infinity), of 245 mm FL, for eastern Caribbean flyingfish. Juven ile growth rate in H. affinis is sensitive to spatial and temporal var iation in temperature. Growth rates were higher where sea-surface temp eratures were higher, and were higher for juveniles hatched in warmer months (April-July) than in colder months (November-March). Growth rat es were also higher near islands than at more oceanic locations. Varia tion in juvenile growth rates may influence the spatial and temporal v ariation in spawning frequency observed in H. affinis.