Arrenurus (Arrenurus) pseudodistinctus, Zheng & Guo & Zhang, 2022

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, Zootaxa 5174 (1), pp. 55-72 : 58-62

publication ID	https://doi.org/ 10.11646/zootaxa.5174.1.4
publication LSID	lsid:zoobank.org:pub:FDD9ED90-D5F1-4C9F-8DB6-95D2C2B3E49F
DOI	https://doi.org/10.5281/zenodo.6974205
persistent identifier	https://treatment.plazi.org/id/5E2587BD-A055-A83D-FF22-FE0AFECC6C4A
treatment provided by	Plazi
scientific name	Arrenurus (Arrenurus) pseudodistinctus
status	sp. nov.

Treatment

Arrenurus (Arrenurus) pseudodistinctus sp. nov.

( Figs 3–6 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 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.. GoogleMaps 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. GoogleMaps

Diagnosis. Petiole widest in the middle and with two hyaline appendages; hyaline membrane small trapezoid.

Description. Male (n=16; Figures 3–4 View FIGURE 3 View FIGURE 4 ): Idiosoma L 957 (957–1027) (including petiole), W 792 (792–817), L/W ratio 1.21 (1.21–1.26) ( Fig. 3A View FIGURE 3 ). Anterior margin of idiosoma slightly concave ( Fig. 3A View FIGURE 3 ). 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 View FIGURE 3 ). A cuticular structure and a pair of small humps between D 4 and the petiole, and the former V-shaped ( Fig. 3A View FIGURE 3 ). Pygal lobes well developed ( Fig. 3A View FIGURE 3 ). Petiole well-developed, L 165 (165–182), widest in the middle; petiole with two hyaline appendages; hyaline membrane small trapezoid ( Fig. 3A View FIGURE 3 ). The posterior margin of the idiosoma with a triangular extension, covering the base of the petiole ( Fig. 3A View FIGURE 3 ). 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 View FIGURE 3 ). 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 View FIGURE 3 ). 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 View FIGURE 3 ); 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 View FIGURE 4 ); 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 View FIGURE 4 ); 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 View FIGURE 4 ); 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 View FIGURE 4 ); IV-l-4 with a spur.

Female (n=11; Figures 5–6 View FIGURE 5 View FIGURE 6 ): Idiosoma L 1289 (1289–1354), W 1165 (1165–1198), L/W ratio 1.11 (1.11–1.13) ( Fig. 5A View FIGURE 5 ); dorsal furrow complete, dorsal shield L 1025 (1013–1065), W 865 (856–872); Dorsal humps absent ( Fig. 5A View FIGURE 5 ). 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 View FIGURE 5 ). Ap slightly bowed ( Fig. 5B View FIGURE 5 ). 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 View FIGURE 5 ), 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 View FIGURE 6 ); 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 View FIGURE 6 ); 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 View FIGURE 5 ); 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 View FIGURE 6 ).

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 .