鲫耳石重量与年龄的关系及其在年龄鉴定中的作用

THE RELATIONSHIP BETWEEN OTOLITH-WEIGHT AND AGE WITH REFERENCE TO ITS USE IN AGE DETERMINATION FOR CARASSIUS AURATUS

耳石重量在年龄组间重叠较少 ,大小相近的个体 ,年龄大的 ,即生长慢的耳石重量比年龄小的、即生长快的大 ,不同龄组之间耳石重量有显著差异 (P <0 .0 5 )。按年龄组以耳石重量与相应的体长作图 ,可初步判断观测年龄的可靠性 ,分析耳石重量频率分布能分离出体长相近、年龄不同的个体 ,其结果与耳石年轮观测的基本一致。耳石重量与年龄呈显著线性正相关 (P <0 .0 5 ) ,用耳石重量与年龄关系估算的年龄与从耳石上直接读取的年龄无显著差异 (P>0 .0 5 )。文中对耳石重量直接用于确定鱼类年龄的可能性作了分析和探讨。

The relationship between otolith weight and age in Carassius auratus and the use of otolith weight for validating annulus counts on otolith were being investigated.It was exhibited that otolith weight had little overlaps among age classes,and for individuals with similar body length,the older (slower growing)had bigger otolith weight than the younger(faster growing).There were significant differences in otolith weight among different age classes(ANCOVA,body length as covariate)and the otolith weight had significantly positive linear relationship with age (P<0.05).The age readings could be verified by plotting the otolith weight vs body length for age classes,and the individuals with similar body length but different ages could be separated by otolith weight frequency analysis.It was demonstrated that the 'estimated' ages from regression between otolith weight and ages had no significant differences with the 'true' ages from annulus counts on otolith.It was suggested that the otolith weight was a useful technique for validating the accuracy of age determination from annuli counting, especially for the individuals with similar size.Meanwhile, the potential of otolith weight for direct estimation of ages of C.auratus were explored by the authors in this paper.