Rhynchaturus rucuensis n. sp. Zoobank: 505AC1E6-1E16-4370-92E5-998F214D47D1 (Figure 6 A­D) Material examined. Holotype male, Río Rucue, W of Antuco, prov. Biobío, Chile, 37°20.588 ′ S 71°47.817 ′ W, 452 m a.s.l., 8 Dec. 2018 (RMNH). Paratype: one male, same date as holotype (RMNH). Diagnosis. Male: Dorsal shield with a pair of small platelets posterior to the large central platelets, Cxgl­4 lying in the posteromedial corner of Cx­IV, idiosoma with a pair of large posterolateral glandularia tubercles, genital field with three pairs of acetabula. Description. Male: Integument less rugose compared to other species of the genus. Idiosoma dorsally 470 (454) long and 397 (413) wide, ventrally 559 (567) long. Dorsal shield with six paired platelets, the anteromedial pair with the postocularia, the posteromedial pair and the two lateral pairs each with a glandularium (Figure 6A). The large central pair is 176 long and is without glandularia, as is the pair of small platelets posterior to the large central platelets. Dorsal projection of camerostome as long as Cx­I. Idiosoma with a pair of large posterolateral glandularia tubercles. Integument less rugose compared to other species of the genus. Gnathosomal bay U­shaped. Gnathosoma attached to a long protrusible tube. Area between the coxae chitinized. Cxgl­ 4 in posteromedial corner of Cx­IV. Genital field with three pairs of acetabula. Gonopore occupying only a small area of genital field (Figure 6B), 34 long; genital field 92 long and 120 wide. Length of P1­5: 12, 42, 34, 50, 34. Palp stocky, especially P4; P4 with two anteroventral fine setae, claws of P5 large (Figure 6C). Length of I­leg­4­6: 110, 102, 78. Length of IV­leg­4­6: 130, 162, 120. Leg claws with large ventral and dorsal clawlets, legs without swimming setae (Figure 6D). Female: Unknown. Etymology. Named after the type locality, the Rucue River. Remarks. The species keys out with the key in Cook (1988) as R. circularis Cook, 1988, known in the female sex only. Females of the latter species have Cxgl­4 lying in the middle of Cx­IV and the idiosoma shape is circular (more elongated in the new species). The position of Cxgl­ 4 in the new species differs from all other species, which have these glandularia in the middle of Cx­IV.

Published as part of Smit, Harry, 2021, New records of water mites from Chile (Acari: Hydrachnidia), with the description of three new species, pp. 274-290 in Acarologia 61 (2) on pages 285-286, DOI: 10.24349/acarologia/20214430, http://zenodo.org/record/5392660