Arrenurus (Arrenurus) pseudodistinctus Zheng & Guo & Zhang 2022, sp. nov.
Creators: name: Zheng, Yulin
name: Guo, Jianjun
name: Zhang, Runzhi
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Trombidiformes
Arrenuridae
Arrenurus
Arrenurus pseudodistinctus

description: Arrenurus (Arrenurus) pseudodistinctus sp. nov.
(Figs 3–6)
Material examined. Holotype male, GUGC, Slide No. JL-AR-2019072301, Baicheng City, Jilin Province, P. R. China (45°37′46″N, 122°50′43″E; alt. 150 m), 23-VII-2019, Haitao Li leg.. Paratypes, 8/6/0, Slide No. JL-AR-2019072302–JL-AR-2019072310 (same data as holotype); Slide No. YN-AR-2018081110–YN-AR-2018081113, Mengla County, Yunnan Province P. R. China (101°06′28″N, 21°08′43″E), 11-VIII-2018, Zhuhui Ding leg.. 8/5/0.
Diagnosis. Petiole widest in the middle and with two hyaline appendages; hyaline membrane small trapezoid.
Description. Male (n=16; Figures 3–4): Idiosoma L 957 (957–1027) (including petiole), W 792 (792–817), L/W ratio 1.21 (1.21–1.26) (Fig. 3A). Anterior margin of idiosoma slightly concave (Fig. 3A). Dorsal furrow incomplete, reaching to base of the pygal lobes; anterior margin of dorsal shield convex, dorsal shield W 483 (468–491); D 1 to D 4 almost on an oblique line, D 3 and D 4 on humps; dorsal humps well developed, and pointing towards anterior of idiosoma (Fig. 3A, C). A cuticular structure and a pair of small humps between D 4 and the petiole, and the former V-shaped (Fig. 3A). Pygal lobes well developed (Fig. 3A). Petiole well-developed, L 165 (165–182), widest in the middle; petiole with two hyaline appendages; hyaline membrane small trapezoid (Fig. 3A). The posterior margin of the idiosoma with a triangular extension, covering the base of the petiole (Fig. 3A). Cx-I and Cx-II extending well beyond the anterior margin of the idiosoma; medial margin of Cx-IV twice the length of Cx-III (Fig. 3B). ACG medium L 264 (259–269); PCG medium L 306 (298–311); Gb–Cx-IV 457 (449–457); Gb–Gp 547 (547–594); Gb–Ep 640 (635–683); Ap enlarged medially, extending to lateral margins of idiosoma, lateral parts narrower (Fig. 3B). L of palp segments: P-I 39 (31–39), P-II 90 (89–99), P-III 73 (72–79), P-IV 116 (116–121), P-V 55 (53–59) (Fig. 3D); P-2 without (or: 0–4) ventral setae; L of leg segments: L of I-L-1–6: 66 (65–68), 138 (139–148), 155 (145–155), 185 (184–187), 176 (176–186), 223 (223–238) (Fig. 4A); L of II-L-1–6: 88 (79–88), 153 (142–160), 169 (156–169), 212 (209–215), 207 (207–222), 266 (254–266) (Fig. 4B); L of III-L-1–6: 104 (104–115), 177 (177–187), 155 (155–167), 215 (194–219), 216 (205–216), 225 (190–225) (Fig. 4C); L of IV-L-1–6: 161 (153–161), 260 (196–260), 193 (190–207), 270 (240–270), 149 (149–164), 209 (201–218) (Fig. 4D); IV-l-4 with a spur.
Female (n=11; Figures 5–6): Idiosoma L 1289 (1289–1354), W 1165 (1165–1198), L/W ratio 1.11 (1.11–1.13) (Fig. 5A); dorsal furrow complete, dorsal shield L 1025 (1013–1065), W 865 (856–872); Dorsal humps absent (Fig. 5A). Cx-I and Cx-II not extending beyond anterior margin of idiosoma; Cx-IV almost without a medial margin; ACG medium L 261 (256–261); PCG medium L 314 (292–314); Gb–Cx-IV 424 (404–448); Gb–Gp 487 (485–498); Gb–Ep 950 (950–973) (Fig. 5B). Ap slightly bowed (Fig. 5B). Gp L 147 (147–161), W 177 (168–185); L of palp segments: P-I 41 (40–46), P-II 76 (76–102), P-III 84 (74–90), P-IV 134 (126–134), P-V 51 (44–55) (Fig. 5C), P-II with two (or: 1–3) ventral setae; L of leg segments: L of I-L-1–6: 70 (70–72), 128 (128–134), 137 (137–147), 185 (184–188), 180 (175–184), 182 (182–198) (Fig. 6A); L of II-L-1–6: 72 (72–77), 152 (151–158), 158 (158–163), 213 (197–216), 216 (199–216), 215 (209–215) (Fig. 6B); L of III-L-1–6: 87 (87–93), 154 (154–162), 164 (147–164), 213 (208–216), 210 (202–210), 216 (186–216) (Fig. 5C); L of IV-L-1–6: 142 (142–154), 212 (199–229), 218 (204–218), 287 (276–287), 229 (229–244), 260 (246–260) (Fig. 6D).
Habitat. Inhabiting a lentic pool in the stream bed with dead branches and rotten leaves.
Distribution. China (Jilin, Yunnan).
Etymology. “ Pseudo- ” means false; the news species is named after its similar species, Arrenurus (Arrenurus) distinctus Marshall, 1919.
Remarks. The new species is close to Arrenurus (Arrenurus) distinctus Lundblad, (1969). However, the new species differs from A. (A.) distinctus in the following points, particularly in the male: (1) With hyaline membrane in the new species, but without in A. (A.) distinctus; (2) Ligulate process well-developed in the new species, but relatively short in A. (A.) distinctus; (3) Cx-I and Cx-II much extending beyond anterior idiosoma margin in the new species, but not in A. (A.) distinctus.
The new species is similar to Arrenurus (Arrenurus) kantakaphorus Cook, 1967 (Cook 1967) collected from India, but they differ from each other by the following: (1) The petiole is shorter (165–182) in the new species, but longer (319) in A. (A.) kantakaphorus. (2) petiole with two hyaline appendages in the new species, but with a spoonshaped central piece in A. (A.) kantakaphorus.
Also, the new species is similar to Arrenurus (Arrenurus) confinis Lundblad, 1969 (Lundblad 1969). However, the new species differs from A. (A.) confinis in the following points: (1) The petiole has no setae in the new species, but has a pair of setae in A. (A.) confinis. (2) Hyaline membrane small and trapezoid in the new species, but bigger in A. (A.) confinis.
description: Published as part of Zheng, Yulin, Guo, Jianjun & Zhang, Runzhi, 2022, Three new and two newly recorded species of the water mite genus Arrenurus Dugès, 1834 (Acari, Hydrachnidia: Arrenuridae) from China, pp. 55-72 in Zootaxa 5174 (1) on pages 58-62, DOI: 10.11646/zootaxa.5174.1.4, http://zenodo.org/record/6973058