Rearing Method and Daily Otolith Ring of Japanese Sardine Larvae

Abstract

Japanese sardine larvae Sardinops melanostictus hatched out from field-collected eggs, were successfully reared for 30 days with the survival rate of 13 % of initial egg number. The relation between rearing days (D) and number of sagittal otolith rings (N) was expressed by the linear regression of N=0.99D —1.88 based on the 31 reared larvae, and the slope is not significantly different from 1 (p>0.05). It is proved that ring on the otolith is formed daily. The first ring is formed mainly 3 (2–5) days after hatching which coincides with the first feeding. © 1989, The Japanese Society of Fisheries Science. All rights reserved.