Metacyclops mendocinus mendocinus (Wierzejski, 1892)

Metacyclops mendocinus mendocinus (Wierzejski, 1892) View in CoL

Fig. 27 View Figure 27

Diagnosis. Adult female, 1,150 µm in length excluding caudal setae. The P4 intercoxal sclerite bears a distal patch and irregular rows of spinules; coxa with two outer rows proximally ( Fig. 27B View Figure 27 ); inner apical spine of P4-endopod is 2.3 times the length of the outer one ( Fig. 27A View Figure 27 ). P5 inner terminal spine is 2.5 times shorter than outer terminal one ( Fig. 27C View Figure 27 ). Inner and outer terminal seta of the caudal ramus about the same length; inner middle terminal seta of caudal ramus is less than 2 times the length of the ramus; caudal ramus 5.1 times longer than wide ( Fig. 27D View Figure 27 ). Genital double somite as long as wide; seminal receptacle with short lateral projections, with a wide proximal and tapered distal part ( Fig. 27E View Figure 27 ).

Remarks. The specimen illustrated was collected in the Iguaçu River, in the Foz do Areia reservoir, which receives effluents from a large city. Perbiche-Neves et al. (2014) noted that this species occurs in impacted reservoirs, which was confirmed in this study. This species is widely distributed in reservoirs in the southeast-south regions of Brazil. Reid

A

(1985) reported its occurrence in some South American countries. It can be easily identified by its 2-segmented P4 and relatively long caudal rami compared to Metacyclops and Microcyclops .