Pillai P M, Unnikrishnan V, Kumar U Suresh
Central Agricultural University, Iroisemba, Manipur, India 795004.; Email:
Post Graduate Department of Zoology and Research Centre, Mahatma Gandhi College, Thiruvananthapuram, Kerala, India 695004; Email: unknown.
Zootaxa. 2014 Feb 28;3768:546-56. doi: 10.11646/zootaxa.3768.5.2.
Macrobrachium abrahami, new species is described from Vamanapuram River, Kerala, South India. DNA bar-coding using Cytochrome B gene sequences has elucidated the taxonomic status of the new species and the ML tree reveals that M. abrahami sp. nov., is phylogenetically close to M. prabhakarani, but morphologically more similar to M. scabriculum. However, the species shares certain morphological characters with M. scabriculum, M. prabhakarani and M. lanatum, but differs remarkably from these three species in distinctive diagnostic characters: rostrum moderately long, convex, distal end directed upwards, rostral formula 12-15/2-3 with 5-6 postorbital teeth, and carapace glabrous. In larger second chelate leg, fingers stout, pubescence restricted to their base; proximal half of cutting edge with fifteen denticles. In smaller second chelate leg, cutting edge of both fingers carry six small denticles situated proximally, distal one comparatively larger. Delicate setae are seen throughout the palm. A row of dark chromatophores is present along the posterio-dorsal margin of uropodal exopods and endopods, close to the base of uropodal setae. The thickness of each band of the row is almost equal to the thickness of uropodal setae.
印度南部喀拉拉邦瓦马纳普拉姆河发现的新物种——亚伯拉罕沼虾（Macrobrachium abrahami）。利用细胞色素B基因序列进行的DNA条形码分析阐明了该新物种的分类地位，最大似然树显示亚伯拉罕沼虾新种在系统发育上与普拉巴卡拉尼沼虾相近，但形态上更类似于粗糙沼虾。然而，该物种与粗糙沼虾、普拉巴卡拉尼沼虾和长毛沼虾具有某些共同形态特征，但在独特的鉴别特征上与这三个物种有显著差异：额剑适度长，凸起，远端向上，额剑公式为12 - 15/2 - 3，有5 - 6个眶后齿，且头胸甲光滑。在较大的第二螯足中，指节粗壮，刚毛仅限于基部；切缘近端一半有15个小齿。在较小的第二螯足中，两指节的切缘近端有6个小齿，远端的一个相对较大。整个掌节有精致的刚毛。在尾肢外肢和内肢的后缘近尾肢刚毛基部处有一排深色色素细胞。这排色素细胞每条带的厚度几乎与尾肢刚毛的厚度相等。
