Andrade-Sossa Camilo, Buitron-Caicedo Lorena, Elías-Gutiérrez Manuel
Grupo de Estudios en Recursos Hidrobiológicos Continentales. Departamento de Biología, Universidad del Cauca, Popayán, Colombia.
Departamento de Sistemática y Ecología Acuática, El Colegio de la Frontera Sur, Chetumal, Quintana Roo, México.
PeerJ. 2020 Sep 24;8:e9989. doi: 10.7717/peerj.9989. eCollection 2020.
The Amazon basin is recognized as one of the most complex and species-rich freshwater environments globally. The diversity of zooplankton here remains unknown, with many species undescribed.
Here, we describe a new species of Schoedler, 1858 (Cladocera: Anomopoda: Daphniidae: Scapholeberinae) from the Colombian Amazon Basin, collected with recently designed light traps. The description is based on detailed morphology (based on SEM and light microscopy) of parthenogenetic females, ephippial females, males, and molecular data based on the COI gene.
n. sp. has a combination of characters present in Sars, 1888 and Dumont & Pensaert, 1983. These are a trilobate rostrum, with the middle lobe well developed with sides straight to relatively rounded, the presence of an elongated slit frontal head pore, a dorsal pore in the juncture of the cephalic shield and the valves, and a single denticulate membrane at the posterior rim of the valves, with stronger setae in the last third. The unique characters of the parthenogenetic females are ventral sucker with delicate triangles. Each has a filament-like projection in the lamellae's inner side and an external section forming convex folds with denticle-like projections in the middle zone of the sucker-plate. There is a peculiar pitted sculpture in the ephippial females and a strong projection in the front of it. The male hook on the limb I with a blunt tip, a quirky lamella-like outgrow in the proximal side, and a paddle with well-developed spines scattered on its surface. The ventral sucker-lamellae in the male is much more developed than the female. The COI gene sequences showed an interspecific mean genetic divergence of 16.4% between n. sp. and the closest species from Mexico, supporting our results. A coalescence analysis and Barcode Index Number also support the new species based on the DNA sequences. New methods of collecting and integrative biology will give important support to recognize the fauna from the Amazon Basin, one of the most important sources of fresh water in the world that remains unknown in many respects.
亚马逊盆地被认为是全球最复杂且物种丰富的淡水环境之一。这里浮游动物的多样性仍然未知，许多物种尚未被描述。
在此，我们描述了一种采自哥伦比亚亚马逊盆地的1858年的朔德勒属（枝角亚目：端足目：蚤科：舟形蚤亚科）新物种，是用最近设计的光诱捕器采集到的。该描述基于孤雌生殖雌体、具卵鞍雌体、雄体的详细形态（基于扫描电子显微镜和光学显微镜）以及基于细胞色素氧化酶亚基I（COI）基因的分子数据。
新物种具有1888年的萨斯属和1983年的杜蒙特与彭萨特属所具有的一系列特征组合。这些特征包括三叶形的吻部，中叶发育良好，两侧直或相对圆润；存在细长的额头部裂缝状孔；在头盾与壳瓣的交界处有一个背孔；在壳瓣后缘有单一的具齿膜，后三分之一处有更强壮的刚毛。孤雌生殖雌体的独特特征是腹吸盘带有精致的三角形。每个三角形在薄片内侧有丝状突起，外部部分在吸盘板中间区域形成带有齿状突起的凸褶。具卵鞍雌体有奇特的凹坑状纹饰，且其前方有一个强烈的突起。雄体第一对附肢上的钩尖端钝圆，近端有一个奇特的片状突出物，还有一个表面散布着发育良好的刺的桨状结构。雄体的腹吸盘薄片比雌体发达得多。COI基因序列显示新物种与来自墨西哥的最接近物种之间的种间平均遗传差异为16.4%，支持了我们的结果。基于DNA序列的合并分析和条形码索引号也支持该新物种。新的采集方法和综合生物学将为识别亚马逊盆地的动物群提供重要支持，亚马逊盆地是世界上最重要的淡水来源之一，在许多方面仍然未知。
