University of Peshawar, Department of Zoology, Peshawar, Pakistan.
Braz J Biol. 2021 Aug 6;83:e243975. doi: 10.1590/1519-6984.243975. eCollection 2021.
In South and South East Asia three genera of fish species i.e. Tor, Neolissochilus and Naziritor are commonly known as Mahseer with at least 47 species. Among these 23 belongs to genus Tor, 22 to Neolissochilus and one to Naziritor i.e. Naziritor zhobensis. Recently another species added to genus Naziritor is Naziritor chelynoides in India. Among Tor species Tor putitora (Hamilton) is the most widely distributed Mahseer in Pakistan and other countries of the Indian subcontinent. However, based alone on morphological characters some authors identify the Pakistani counterparts as Tor macrolepis (Heckel), (a species presumed to be found exclusively in the Indus River system) distinct from Tor putitora (a species found in Ganga Brahmaputra River system). In order to resolve this taxonomic ambiguity, present study carried out meristic and morphometric measurements of Mahseer collected from a total of 11 water bodies of Pakistan. Ratios between the morphometric characters were calculated and statistically analyzed using t-test and correlation coefficient. Two species identified as Tor putitora and Naziritor zhobensis were the sole Mahseer inhabitants of Indus system in Pakistan. Tor putitora occurred at all surveyed sites while Nazirtor zhobensis had a distribution range from river Zhob to tributaries of river Gomal the right bank tributaries of River Indus. The study corroborates that there are no unequivocal morphological synapomorphies in any existing populations of both species. The study further demonstrates that head length, a character frequently used in Mahseer taxonomy, is not a good measure for species identification. Finally the present study establishes that Naziritor zhobensis still exists in the water bodies of Pakistan and that golden Mahseer occurring in Indus riverine system of Pakistan is Tor putitora.
在南亚和东南亚，有三个鱼类属，即 Tor、Neolissochilus 和 Naziritor，通常被称为 Mahseer，共有至少 47 个物种。其中 23 种属于 Tor 属，22 种属于 Neolissochilus 属，一种属于 Naziritor 属，即 Naziritor zhobensis。最近，印度又增加了一个 Naziritor 物种，即 Naziritor chelynoides。在 Tor 属中，Tor putitora (Hamilton) 是巴基斯坦和印度次大陆其他国家分布最广的 Mahseer。然而，仅基于形态特征，一些作者将巴基斯坦的 Tor macrolepis (Heckel)（一种被认为仅存在于印度河流域的物种）鉴定为与 Tor putitora（一种存在于恒河-雅鲁藏布江流域的物种）不同。为了解决这个分类学上的模糊性，本研究对从巴基斯坦的 11 个水体中采集的 Mahseer 进行了可数和形态测量。计算了形态特征之间的比值，并使用 t 检验和相关系数对其进行了统计分析。两种被鉴定为 Tor putitora 和 Naziritor zhobensis 的鱼类是巴基斯坦印度河流域的唯一 Mahseer 居民。Tor putitora 出现在所有调查的地点，而 Nazirtor zhobensis 的分布范围从 Zhob 河到 Gomal 河的支流，再到印度河的右岸支流。研究证实，这两个物种在任何现有种群中都没有明确的形态同源特征。研究进一步表明，头部长度，一个在 Mahseer 分类学中经常使用的特征，并不是一个很好的物种识别测量方法。最后，本研究确立了 Naziritor zhobensis 仍然存在于巴基斯坦的水体中，而在巴基斯坦印度河流域系统中出现的金色 Mahseer 是 Tor putitora。
