Microcyclops anceps subsp. anceps

Microcyclops anceps anceps (Richard, 1897) Figs 28, 29, 30 Diagnosis. Adult female, 720 µm in length excluding caudal setae (Fig. 28A). The distal margin of the second prosomite bears an ornate scalloped membrane, and the other segments have smooth membrane (Figs 28B, 29B, C). Caudal ramus 3.1 times longer than wide (Figs 28C, 29A). The P1 endopod terminal segment has a pore close to the outer margin in anterior view; P1 endopod terminal spine serrated shape slightly asymmetric compared to Microcyclops finitimus and Microcyclops ceibaensis (Figs 28D, 30A, B, C). The inner apical spine on the terminal P4 endopod segment 1.4 times longer than the outer spine (Fig. 30D). P5 last segment 2.4 times longer than wide; P5 terminal spine 1.6 times shorter than the width of its segment in the middle portion (Fig. 30E). Remarks. The specimen was collected in the upper stretch of the Paraguay River. Rocha (1998) provided simple and practical characteristics for the identification of five species of Microcyclops that occur in Brazil. Microcyclops anceps is widely distributed in South America (Dussart and Frutos 1985, José de Paggi and Paggi 2008). Reid (1985) reported it from Brazil, Argentina, Bolivia, Chile, Ecuador, Paraguay, Peru, Uruguay, Venezuela, Central America, and Mexico and Gutiérrez-Aguirre and Cervantes-MartÍnez (2016) examined specimens also from Guyana and Guatemala.