南极南设得兰群岛南极电灯鱼耳石形态学研究

Otolith morphology of Antarctic lanternfish Electron antarctic in the South Shetland Islands,Antarctic

为了研究南设得兰群岛南极电灯鱼Electrona antarctica耳石形态指标的生长特征,利用2012年12月至2013年2月于南设得兰群岛收集的100尾南极电灯鱼(体长72.67~91.81 mm)样本进行了分析,并利用回归分析、赤池信息准则(AIC)拟合和差异性t检验等方法,对其耳石形态的各项指标,包括耳石长、耳石宽、基叶长度、翼叶长度、耳石面积和耳石周长等进行了分析。结果表明:南极电灯鱼体长与体质量密切相关,关系式为WW=2.5086×10^(-5)L_S^(2.8586)(R^2=0.7187,P<0.05);耳石相对于其体型较大,耳石长与耳石宽接近,耳石主间沟与主凹槽清晰,翼叶和基叶长度接近,均不发达;左耳石长和宽分别为3.00~3.81 mm、2.98~3.62 mm,右耳石长和宽分别为2.99~3.72 mm、3.05~3.67 mm;耳石指标中,耳石宽和周长较其个体体长稳定,而翼叶和基叶长度变化最不稳定,左、右耳石的基叶长、周长存在显著性差异(P<0.05),左、右耳石的全长、面积不存在显著性差异(P>0.05);左、右耳石的长、宽、面积和周与鱼体体长密切相关;生长过程中,耳石面积最为稳定,其与鱼体体长回归关系最高,耳石短轴生长比耳石长轴生长稳定,耳石的生长方向偏向于厚度的增加以及面积的变大。本研究结果可为今后南极电灯鱼年龄与生长的研究提供基础数据。

The morphometrical parameters including length,weight,length of antirostrum,length of rostrum,circumference and acreage of 100 sagittal otoliths were measured and analyzed in Antarctic lanternfish Electrona antarctica samples with standard length from 72.67 mm to 91.81 mm collected from the South Shetland Islands from December 2012 to February in 2013 by methods of regression analysis,Akaike information criterion（AIC） fitting model test and t test.The results showed that the relationship between the standard length and wet body weight was expressed as WW= 2.5086 × 10-5LS2.8586（R2= 0.7187,P 〈 0.05）.Responding to body length,the lanternfish has large otolith,whose length was close to the width of otolith in size.The otolith has clear excisural notch and the sulcus,and the rostrum and the antirostrum are almost the same in length,although they are not obvious.The length of otolith was ranged from 3.00 mm to 3.81 mm in the left and from 2.99 mm to 3.72 mm in the right and the width of the otolith was varied from 2.98 mm to 3.62 mm in the left and from 3.05 mm to 3.67 mm in the right.The width and circumference of otolith showed stable variation with the growth of fish,however,the variation in rostrum and the antirostrum of otolith were remarkable varies for all otolith morphological parameters.A significant difference in the length of antirostrum and circumference of the otolith was found between the left and the right,but unremarkable differences in total length and acreage.The close relationship was found between the standard length of fish and the length,the width,the area,and the perimeter of the otolith.There was a linear relationship between the standard length and body weight of the lanternfish and circumference and acreage of otolith.The most stable acreage of the otolith showed a higher relationship with the standard length of the fish,with more stable growth of total length in the otolith than that of width in otolith.The findings provide the essential data with the study of age and growth of Electrona antarctica in the future.