Mercado-Salas Nancy F, Suárez-Morales Eduardo, Maeda-Martínez Alejandro M, Silva-Briano Marcelo
El Colegio de la Frontera Sur (ECOSUR) Unidad Chetumal, A. P. 424. Chetumal, Quintana Roo 77014, Mexico.
Zookeys. 2013 Apr 11(287):1-18. doi: 10.3897/zookeys.287.4358. Print 2013.
A new species of the freshwater cyclopoid copepod genus Metacyclops Kiefer, 1927 is described from a single pond in northern Mexico, within the binational area known as the Chihuahuan Desert. This species belongs to a group of Metacyclops species with a 3443 spine formula of swimming legs. It is morphologically similar to Metacyclops lusitanus Lindberg, 1961 but differs from this and other congeners by having a unique combination of characters, including a caudal rami length/width proportion of 3.5-3.8, a innermost terminal seta slightly longer than the outermost terminal seta, intercoxal sclerites of legs 1-4 naked, a strong apical spine of the second endopodal segment of leg 1 and one row of 6-8 small spinules at the insertion of this spine. The finding of this species represents also the first record of the genus in Mexico and the third in North America, where only two other species, Metacyclops gracilis (Lilljeborg, 1853)and Metacyclops cushae Reid, 1991 have been hitherto reported. This is also the first continental record of a species of Metacyclops from an arid environment in the Americas. This species appears to be endemic to the Chihuahuan Desert, thus emphasizing the high endemicity of this area.
在墨西哥北部一个位于被称为奇瓦瓦沙漠的跨境区域内的池塘中，发现了淡水剑水蚤属（Metacyclops Kiefer，1927）的一个新物种。该物种属于具有游泳足3443刺式的剑水蚤物种群。它在形态上与1961年的葡萄牙剑水蚤（Metacyclops lusitanus Lindberg）相似，但与该物种及其他同属物种不同，具有独特的特征组合，包括尾叉长宽比为3.5 - 3.8，最内侧的末端刚毛略长于最外侧的末端刚毛，第1 - 4对足的基节间骨片无刚毛，第1对足内肢第二节有一根强壮的顶端刺，且在该刺的着生处有一排6 - 8根小刺。该物种的发现也是该属在墨西哥的首次记录以及在北美的第三次记录，此前在北美仅报道过另外两个物种，即纤细剑水蚤（Metacyclops gracilis，Lilljeborg，1853）和库氏剑水蚤（Metacyclops cushae Reid，1991）。这也是美洲干旱环境中剑水蚤属物种的首个大陆记录。该物种似乎是奇瓦瓦沙漠特有的，从而凸显了该地区的高特有性。
