Relationship between daily-growth increment of otolith and growth of Japanese parrotfish(Oplegnathus fasciatus)

Daily-growth increment of otolith and growth of Japanese parrotfish(Oplegnathus fasciatus)were studied and research objects were taken from Zhoushan Fishries Research Institute in April 2009.Microscopic observation was performed on the growth of the otolith during the embryonic development of artificially fertilized eggs and the formation of the first daily growth increment on otolith of larvae.The initial daily growth increment in otolith was formed on the second day after hatching,and continued on a daily schedule under normal conditions.Daily age(N)of otolith were shown by daily growth increments(D)plusing 1,and the equation was N=D+1;and on the 8th day,there was a second check,called first feeding check.After biological measurements of the samples,the sagittal otoliths were removed from the fish and sections were made to examine their sizes,morphology,number and widths of daily growth increments by light microscopes.The longest radius r s (μm)of the otolith was linearly related to the fish length L(mm),the equation is r s =18.146L-44.436;the radius(r s )of sagitta was linearly related to the radius(r l )of lapillus too,the equation is r s =0.612 5 r l +1.988 2.