FECUNDITY AND SPAWNING FREQUENCY OF THE HAWAIIAN ANCHOVY OR NEHU, ENCRASICHOLINA PURPUREA

Female nehu can begin spawning at 35 mm standard length; almost all fish over 40 mm 8L from Kaneohe Bay were mature and in spawning condition. Mature females were found in all months of the year. Females from summer (May-October) had higher fecundity and relative cost per batch than fish from winter (November-April). In nehu and most other anchovies. fecundity appears to increase exponentially with weight. Nehu appear to be distinguished from other species by a higher exponent and consequently greater increase in relative fecundity over the reproductive size range. Nehu spawn during a short period 1 or 2 hours after sunset and begin hydrating ova only a few hours before spawning. Data on presence or absence of hydrated ova or postovulatory follicles along with differences in oocyte size in fish collected from throughout the diel cycle indicated that, after spawning, nehu can ripen a new batch of oocytes in 2 days and that most females spawn every other day. The estimated requirements for continued spawn-ing at this rate indicate that individual variation in recent feeding success or stress could be responsible for observed scatter about fecundity-weight relationships and deviation from the normal spawning frequency. The nehu, Encrasicholina purpurea, is a small an