Arrenurus surinamensis, Smit, 2020

Smit, Harry, 2020, New records of the water mite genus Arrenurus Dugès, 1834 from South America (Acari: Hydrachnidia: Arrenuridae), with the description of five new species and one new subspecies, Acarologia 60 (2), pp. 371-389 : 383-385

Arrenurus surinamensis n. sp

Zoobank: 1890056E-62CD-4357-A995-E030C560AA77

( Figure 9 )

Material examined — Holotype male, roadside pond along Afobakaweg , Surinam, 5°36.266 N 55°05.988 W, alt. 13 m asl, 19-xi-2019 ( RMNH) . Paratypes: three females, same data as holotype ( RMNH).

Diagnosis — Male: Anterior part of idiosoma wide, dorsal shield distanced from anterior idiosoma margin, with Dgl-2 and Dgl-3 close together. Cauda relatively short, with a rounded posterior margin. Female: Cx-IV without medial margin.

Description — Male: Idiosoma yellowish, dorsally 794 long and 492 wide, ventrally 818 long. Dorsal shield 388 wide, Dgl-2 and Dgl-3 close together, postocularia more or less between accompanying setae of Dgl-2. Distance dorsal shield – anterior idiosoma margin 178. Cauda relatively short, with a rounded posterior margin; Dgl-4 on small humps. Gonopore 40 long, genital field swollen, extending to lateral idiosoma margin; genital field 324 wide Length of P1-5: 28, 62, 34, 68, 38; P2 medially with two small setae, antagonistic bristle of P4 short. Lengths of I-leg-4-6: 90, 88, 90. Length of IV-leg-4-6: 152, 138, 140; IV-leg-4 without spur. Legs with numerous swimming setae.

Female: Idiosoma dorsally 697 (697-713) long and 603 (603-624) wide, ventrally 713

(697-729) long. Dorsal shield complete, 575 (567-575) long and 470 (470-494) wide. Cx-I slightly extending beyond anterior idiosoma margin, Cx-IV without medial margin. Gonopore 112 long, genital field 458 wide. Genital plates relatively broad Length of P1-5: 24, 42, 70, 30; palp as in male. Length of I-leg-4-6: 86, 84, 82. Lengths of IV-leg-4-6: 114, 98, 96. Legs with numerous swimming setae.

Etymology — Named after the country of the type locality.

Remarks — The new species is most close to Arrenurus nitidus K. Viets, 1937 from Brazil, known from the male only. The latter species differs in a less wide anterior idiosoma (including the dorsal shield), a different configuration of the glandularia and associated setae of the dorsal shield (compare Figure 179 of K. Viets (1954a) with Figure 9A ) and a straight posterior margin of the cauda. Unfortunately, Viets (1954a) didn’t illustrate the postocularia of A. nitidus .

Figures

Figure 9 Arrenurus surinamensis n. sp., A-D holotype male, E paratype female. A – dorsum; B – venter; C – left palp; D – right palp; E – venter. Scale bars: A-B = 100 µm, C-D = 50 µm.