作　　者： ; ; ;

机构地区： 四川大学生命科学学院

出　　处： 《动物学报》 2003年第4期508-513,共6页

摘　　要： 将野生和人工繁殖的草鱼仔鱼的耳石取出并置于显微镜下观察微结构特征。结果表明 :草鱼耳石一般有一个圆形或卵圆形的原基和中心核 ,但有 0 4 1%～ 4 6 7%的样本具有双原基或双中心核。343尾野生仔鱼中 ,6 71%的个体在矢耳石和微耳石上具有营养转换标记 ,而 187尾人工繁殖的仔鱼中 ,在矢耳石和微耳石上出现营养转换标记的比例分别是 6 4 17%和 5 0 80 % ;在营养转换标记处 ,矢耳石和微耳石的直径分别为 5 4 12±9 4 9μm和 4 0 4 8± 7 0 2 μm (n =5 0 ) ;133尾野生仔鱼在转入实验室饲养的过程中 ,86 4 7%的个体在耳石上形成了转移标记 ;野生仔鱼生长轮纹清晰的矢耳石 (n =5 2 1)和微耳石 (n =5 2 1)样本的比例分别低于 10 %和2 5 % ,但在人工饲养仔鱼中 ,95 0 0 %个体的矢耳石 (n =186 )和 88 0 0 %个体的微耳石 (n =184 )具有清晰的生长轮纹 ;野生仔鱼经人工饲养后 ,其耳石上在饲养期间沉积的生长轮的清晰度亦明显比在野外生存期间沉积的高 ;对比实验显示饥饿对仔鱼耳石生长轮的清晰度没有明显的影响. larval grass carp (Ctenopharyngodon idellus) were collected from the Jiujiang, Shimatou, and Shamao sections of the middle reaches of the Yangtze River, and Honghu County’s Baizhi hatchery from 1998-1999. Some larvae were killed immediately and preserved in 100% ethanol, the rest were brought to the laboratory and reared for half month then killed and preserved in 100% ethanol. Otoliths of the larvae were removed and examined under a microscope. The results show that, there was usually one round or oval primordium and nucleus in each otolith, but in a few specimens (0 41%-4 67%) there were double primordia or nuclei in each otolith. 6 71% of 343 wild larvae had a visible growth check in both sagittae and lapilli indicative of a change in nutrition, but the frequencies of such checks were obviously higher in the sagittae (64 17%) and lapilli (50 80%) of the 187 laboratory-reared larvae. The diameters of these checks were 54 12±9 49 μm in the sagitta and 40 48±7 02 μm in the lapillus (n=50). A transitional growth check was found to have formed in the in otoliths of 86 47% of the 133 wild larvae reared in captivity while these were being carried from the field to the laboratory. Growth increments could be identified clearly in only a few of the otoliths (10% and 25% in the sagittae and lapilli respectively) of wild larvae in, but were clearly visible in more than 95 00% of the sagittae and 88 00% of the lapilli of hatchery-reared larvae . In those wild larvae that were reared artificially for a period of time, the clarity of growth increments formed during captivity was also evidently higher than those formed in the wild. No effect of starvation on the deposition of growth increments in otoliths was observed.

关 键 词： 草鱼 仔鱼 耳石 自然标记 生长轮 清晰度

领　　域： [生物学]