用鳞片和耳石鉴定鲫年龄的比较研究

两观测者独立观测了分别采自洪湖的175尾和洞庭湖的168尾鲫样本的鲜片和耳石，结果显示鳞片适于鉴定年龄组成简单、生长较快的洞庭湖鲫种群的年龄，两观测者年轮读数的总吻合率可达90.5%，与耳石上年轮读数的吻合率也可高达91.7%；但用鳞片鉴定年龄结构复杂、生长缓慢的洪湖鲫种群年龄，两观测者总吻合率只有50.9%，各龄组吻合率随年龄上升而迅速下降。与耳石上年轮读数总吻合率也仅为56.6A%，存在比耳石低估高龄个体年龄的问题，用耳石鉴定鲫年龄具有易于识别、精确度高的优点，用之鉴定洪湖和洞庭湖鲫种群年龄，两观测者年轮读数的总吻合率都很高，分别为92.7%和97.0%，且随年龄上升，依然可保持较高的精确度，对洪湖鲫种群应用耳石为宜。

COMPARISON OF SCALE AND OTOLITH FOR ESTIMATING AGE OF ARASSIUS AURATUS L

The precision of age determinations of C.auratus between two readers and the use of scale and otolith (lapillus) from 175 and 168 individual fish collected in the Honghu Lake and the Dongting Lake, respectively, were compared. Ages assigned to scales and otoliths by the two independent readers agreed 50.9% and 92.6% for samples from the Honghu Lake and 90.5% and 97.0% for those from Dongting Lake of the same time, respectively. Age agreement between scales and otoliths was low (56.6% and 41.7% for reader 1 and reader 2, respectively) in the Honghu Lake population and high (91.7% and 82.1% for reader 1 and reader 2, respectively) in the Dongting Lake population. Generally, more annuli were detected on otoliths than on scales as fish age exceeded 4 years, and the maximum ages identified were 8 years from otoliths, 6 from scales in the Honghu Lake population. It is demonstrated that scale is only useful for estimating age of the C.auratus population with few age groups and rapid growth, and otolith is a better structure than scale to use for estimating age of C. auratus , especially for the population with slow growth and more age groups like that from the Honghu Lake.