Abstract

Studies on phenotypic variations among isolated populations help towards understanding the divergent natural selection acting on species. This study examines phenotypic variations among wild populations of an important Indian major carp, Cirrhinus mrigala (Hamilton, 1822) collected from ten locations throughout its distribution range in the Ganga River, India covering up- and downstream of all the four barrages (Bijnor, Narora, Kanpur and Farakka) to assess the implications of physical barriers on longitudinal connectivity of the Ganga River. Landmark based truss morphometric analysis and multivariate analyses were used to quantify the extent of morphological differences among populations. Post-hoc paired comparisons, discriminant function analysis and Mahalanobis distances revealed morphological differences between up and downstream individuals at all the four barrages. Phenotypic plasticity owing to habitat dissimilarities or due to environment and genotype interactions may play a vital role for these phenotypic differences between fish populations. This study is only a first step to recognize different stocks, and to identify fish movement between sites and therefore can be useful for developing suitable plan for conservation and restoration of fish populations in river ecosystem fragmented by physical barriers.

中文翻译：

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物理障碍对恒河水体纵向形态连通性的影响，通过形态学评估了百里香（Cyprinus mrigala）（Cyprinidae）种群

摘要

对孤立种群之间表型变异的研究有助于理解作用于物种的不同自然选择。这项研究检查了重要印度主要鲤鱼Cirrhinus mrigala的野生种群之间的表型变异。（汉密尔顿，1822年）从分布在印度恒河的十个地点收集了涵盖所有四个拦河坝（比诺，纳罗拉，坎普尔和法拉卡）的上游和下游的十个地点，以评估物理屏障对河道纵向连通性的影响。恒河。基于地标的桁架形态分析和多元分析被用来量化人群之间形态差异的程度。事后配对比较，判别函数分析和马氏距离揭示了在所有四个弹幕中上下游个体之间的形态学差异。由于栖息地的不同或由于环境和基因型的相互作用而产生的表型可塑性可能对鱼类种群之间的这些表型差异起着至关重要的作用。