长湖短颌鲚耳石重量与年龄关系

利用2014年采自湖北长湖的378尾短颌鲚(Coilia brachygnathus)样本,去除包膜和黏液的矢耳石于55℃烘箱中烘烤24 h,电子天平称重(精确至0.001 g),成对t检验结果表明,短颌鲚左右矢耳石重量之间无显著差异(P0.05),数据分析以左右矢耳石重量的平均值计为矢耳石重量;采用直线、幂函数和多项式3种回归方程研究了其耳石重量与年龄的关系。结果显示,长湖短颌鲚的耳石和鳞片均可用于鉴定其年龄,且两者鉴定年龄的吻合度达到75.8%;根据222尾耳石与鳞片年龄一致的短颌鲚样本数据,发现耳石重量与个体的年龄呈显著相关(P0.05);按年龄组以耳石重量与相应的体长作图,可以初步判断所观测年龄的可靠性;利用建立的耳石重量-年龄关系函数估算得到的个体年龄,与直接读取耳石磨片获得的年龄结果无显著差异(P0.05),表明利用矢耳石重量直接推算其个体年龄,可以作为辅助短颌鲚年龄鉴定尤其快速鉴定的一种有效方法。

Relationship of Sagittal Otolith Weight to the Age of Coilia brachygnathus

A total of 378 samples of Coilia brachygnathus were collected from Lake Changhu, Hubei Province, in 2014, in order to reveal the relationship between otolith weight and age. The results indicated that: both otoliths and scales of C. brachygnathus could be used to identify its age, and their matching degree reached 75.8%; there were no significant differences in sagittal otolith weight between left and right otolith; based on 222 samples with consistent age determination by otolith and scales, there was a significant correlation between otolith weight and fish age (P < 0.05); the ages estimated by the relationship between otolith weight and agedid not differ significantly from those observed by traditional annuli counting in otolith sections (P <0.05). It was suggested that direct estimation by using sagittal otolith weight could be a potential effective age estimation method for C. brachygnathus.