胶州湾12种饵料鱼类耳石大小与体长的关系

RELATIONSHIPS BETWEEN OTOLITH SIZE AND FISH SIZE FOR TWELVE PREY FISH SPECIES FROM JIAOZHOU BAY

根据2008年11月至2009年8月在胶州湾海域进行的逐月定点底拖网调查,选择12种常见的饵料鱼类作为研究对象,运用最小二乘法分析了每种饵料鱼类的体长与耳石形态大小(包括耳石的长度、宽度、长半径和短半径)的关系,并建立回归方程,旨在为深入研究高营养级鱼类的摄食生态和食物网营养动力学提供基础资料。研究表明,12种饵料鱼类的体长与体重均呈显著的幂函数关系(P<0.05),回归系数b值在2.871—3.371,平均值为3.159±0.110(95%CL),b值最小的鱼种是六丝钝尾虾虎鱼Amblychaeturichthys hex-anema,最大的是细条天竺鲷Apogon lineatus。经检验,Liza haematocheilus和箭鱼衔Callionymus sagitta的b值与3无显著差异(P<0.05),属等速生长;李氏鱼衔Callionymus richardsonii和六丝钝尾虾虎鱼的b值显著小于3(P<0.05),属负异速生长;其余8种鱼类的b值均大于3(P<0.05),为正异速生长。方差分析表明,12种鱼类的体长与耳石各个形态参数的回归关系均极显著(P<0.01)。在所有48个回归方程中,有37个方程的决定系数R2值大于0.8,拟合效果较好;有9个回归方程的R2值在0.7—0.8;其余2个回归方程的R2值小于0.7,拟合效果略差。其中,各方程拟合效果最好的是六丝钝尾虾虎鱼,其R2值均接近于1。通过比较同种鱼类各个回归方程的R2值可知,在这12种饵料鱼类中,多数鱼种体长与耳石长度和宽度的拟合效果要略好于体长与耳石半径的拟合效果,因此在实际应用中,可以通过测量耳石的长度和宽度来推算饵料鱼类的体长等形态参数。另一方面,由于多数鱼类的耳石比较脆,尤其是耳石的两端更容易破损,因此与耳石长度相比,耳石宽度与体长的回归方程更加适合于实际应用。

Based on the bottom trawl surveys in Jiaozhou Bay from November 2008 to August 2009, the relationships between otolith size （including otolith length, width, long radius and short radius） and fish length of 12 prey fish species were studied in order to provide basic information for further research of feeding ecology of higher trophic level fishes and marine trophodynamics. A total of 1063 samples were collected for all the 12 fish species, belonging to 3 orders, 7 families and 11genera. Results showed that there were significant power functional relationships between length and weight for 12 prey fish species （P〈0.05）. The coefficient of regression （b） in the length-weight relationship functions ranged from 2.871 to 3.371, with the mean value of b being 3.159±0.110 （95% CL）. In all the 12 prey fish species, Amblychaeturichthys hexanema had the lowest value of b and Apogon lineatus had the highest value. T-test showed that Liza haematocheila and Callionymus sagitta presented isometric growth （P〈0.05）, Callionymus richardsonii and A. hexanema presented negative allometric growth （P〈0.05）, and the other 8 species presented positive allometric growth （P〈0.05）. The analysis of variance indicated that the regressions between otolith size and fish standard length were extremely significant （P〈0.01）. In all 48 regression functions, the determination coefficients （R2） were larger than 0.8 in 37 functions, between 0.7 and 0.8 in 9 functions and lower than 0.7 in the rest two functions. Among all the 12 fish species, A. hexanema had the highest value of R2 （close to 1）, while Engraulis japonicus had the lowest value of R2 （lower than 0.8）. According to the value of R2 in different functions of the same species, the regression functions of otolith length and width to fish standard length fitted better than the functions of otolith radius to fish standard length for most fish species. Therefore, the size of prey fishes could be estimated by means of otolith length and width. On the other hand, because the tip of the otolith may be damaged frequently in the stomachs of fish, which made it uneasy to measure accurate otolith length, so the regression function of otolith width to fish standard length is more suitable in practice.