OTOLITH MARKING AND DAILY INCREMENT VALIDATING IN LARVAL AND JUVENILE YELLOWCHEEK CARP,ELOPICHTHYS BAMBUSA

A total of 74 wild larvae of yellowcheek carp (Elopichthys bambusa) were collected in the Honghu section of the Yangtze River on May 16, June 3 and 13,1999.The larvae collected on May 16 were immersed in 100mg/L alizarin complexone (ALC) solution for 24 hours, then in 120mg/L ALC solution for 24 hours seven days later.The larvae collected on June 3 and 13 were immersed in 150mg/L ALC solution for 24 hours.Under UV light, scarlet-pink fluorescent zones were observed on otoliths.Only a few otoliths could be marked when immersed in 100mg/L ALC solution.When immersed in 120mg/L and 150mg/L ALC solutions, 91.3% and 100% lapillus, 44.83% and 58.06% sagitta, and less than 10% as-tariscus were marked, respectively.The relationship between increments in lapillus (N) and the rearing days (D) could be expressed as N = 0.2663 + 0.9276D (n = 68, r2 = 0.9664).The slope 0.9276 was not significantly different from 1.That means the increments in lapillus formed daily in larval and juvenile stages of the fish.The relationships between body length (BL) and diameters of lapillus (LD), sagitta (SD), astariscus (AD) could be expressed as BL= 66.8723LD+2.7064 (n = 73, r2 = 0.8867), BL= 22.7839SD + 6.6066 (n = 49, r2 = 0.8525) for, and BL= 47.6079AD+ 3.5660 (n =71, r2 = 0.9012), respectively.