基于矢耳石重量与年龄关系对北部湾二长棘犁齿鲷年龄鉴定的研究

利用2006年7月至2008年10月北部湾商业捕捞底拖网和流刺网渔获物中采集的1 276尾北部湾二长棘犁齿鲷（Evynnis cardinalis）中1 045尾耳石完整样本,对二长棘犁齿鲷矢耳石重量与年龄关系进行了初步研究.结果显示,北部湾二长棘犁齿鲷左右矢耳石间的重量无显著差异,选用左矢耳石为研究对象;用直线、幂函数和多项式等拟合二长棘犁齿鲷各类参数间的关系,样本体长（L）与矢耳石重量（OW）呈幂函数相关：OW=2.000 0×10-6L2.143 0（R2=0.952 9,n=1 045）;北部湾二长棘犁齿鲷耳石重量与年龄（T）呈二项式关系：OW=0.002 7T2＋0.008 1T＋0.023 5（R2=0.992 5,n=1 045）,矢耳石重量与年龄呈显著的线性相关性.以此估算年龄,与从矢耳石上直接读取的年龄并无显著差异,并且,通过矢耳石重量估算年龄比体长频率法较为准确.因此,在经过适当校正后,矢耳石重量可以作为二长棘犁齿鲷年龄鉴定的有效辅助手段.

Age determination based on the otolith weight of the Cardinal seabream, Evynnis cardinalis, in the Beibu Gulf of the South China Sea

Among 1 276 total Cardinal seabream,Evynnis cardinalis individuals were sampled from the bottom trawl and drift net catches of Beibu Gulf commercial fishing vessel from July 2006 to October 2008.A total of 1 045 intact organisms were used to study the correlation between sagittal otolith weight(OW) and age.The results showed no significant differences between left and right otolith weights.The left otolith data were fit to various parameters by linear,exponential and multinomial regression.The relationship between the length of the sample and OW can be described by OW =2.000 0×10-6L2.143 0(R2=0.952 9,n=1 045),while a linear relationship exists between the OW and age: OW= 0.002 7 T2 + 0.008 1 T + 0.023 5(R2 = 0.992 5,n=1 045).The ages estimated by OW did not differ significantly from those observed by traditional annuli counting in otolith sections.Thus,the OW method is a better technique than the fish length frequency method for estimation of fish ages and can be used to assist in estimation of the Cardinal seabream.