西藏茶巴朗湿地外来种大鳞副泥鳅年龄与生长的研究

Age Structure and Growth Characteristics of Paramisgurnus dabryanus in Chabalang Wetland of Tibet

通过探究茶巴朗湿地内的外来物种大鳞副泥鳅的年龄结构与生长特性,为控制和治理包括大鳞副泥鳅在内的外来鱼入侵提供基础参数。取微耳石作为年龄鉴定材料,对299尾大鳞副泥鳅样本进行研究。结果表明,大鳞副泥鳅已在茶巴朗湿地形成了自然种群,个体体长范围为5.13~16.92 cm,体重范围为1.22~49.89 g;种群由2~8龄共7个年龄组组成,优势年龄组为4~6龄;相关分析表明雌雄的体长与体重无显著性差异,其种群体长体重表达式为W=0.010L2.917,呈匀速生长;逻辑斯谛生长方程为Lt=12.740/(1+e0.803-0.530t),Wt=16.740/(1+e0.803-0.530t)2.917,拐点年龄为3.5龄,对应的体长与体质量分别为9.44 cm、6.99 g。与平原地区相比,茶巴朗湿地大鳞副泥鳅在年龄结构上表现为高龄个体增多;在生长特征上表现为个体减小,生长指标下降,这些变化可能是该外来物种为更好地适应高原低温水环境。

The age structure and growth characteristics of Paramisgurnus dabryanus,an alien species in the Chabalang wetland,are investigated to provide basic parameters to control the invasion of alien fish species including P.dabryanus in Tibet.The otoliths of 299 specimens of P.dabryanus are used as identification materials.The results showed that the body length of P.dabryanus ranged from 5.13 to 16.92 cm,the body weight ranged from 1.22 to 49.89 g,and there were 7 age groups ranging from 2 to 8 years old,while the dominant age group ranged from 4 to 6 years old.Correlation analysis showed that there was no significant difference of body length and body weight between male and female.The related expression of body weight and body length was W=0.010 L2.917,displaying a uniform growth model.The logistic equation of length growth and weight growth was Lt=12.740/(1+e0.803-0.530t),Wt=16.740/(1+e0.803-0.530t)2.917,respectively.The inflection point age of P.dabryanus was 3.5 years old,corresponding to body length and body mass of 9.44 cm and 6.99 g respectively.For the age structure,there were older individuals among P.dabryanus population in the Chabalang wetland when comparing with the corresponding population in plain area.The growth characteristics were characterized by an individual decrease and a decrease of growth index.These changes might be caused by the alien species’adaptation to plateau low temperature water environment.