Arrenurus (Arrenurus) crassicaudatus Kramer, 1875

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 : 64-66

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.6974207
persistent identifier	https://treatment.plazi.org/id/5E2587BD-A05F-A831-FF22-FF36FD1F6B00
treatment provided by	Plazi
scientific name	Arrenurus (Arrenurus) crassicaudatus Kramer, 1875
status

Treatment

( Figs 9–12 View FIGURE 9 View FIGURE 10 View FIGURE 11 View FIGURE 12 )

Material examined. GUGC, Slides No. JL-AR-2018042601–JL-AR-2018042604, Baicheng City, Jilin Province, P . R. China (45°37′46″N, 122°50′43″E; alt. 150 m), 26-IV-2018, Zhuhui Ding leg GoogleMaps .. 2/2/0.

Description. Male (n=2; Figures 9–10 View FIGURE 9 View FIGURE 10 ): Idiosoma L 714 (725) (including petiole), W 588 (574), L/W ratio 1.21 (1.26) ( Fig. 9A View FIGURE 9 ). Anterior margin of idiosoma slightly concave ( Fig. 9A View FIGURE 9 ). Dorsal furrow incomplete and reaching to the middle of the cauda; the front part of the dorsal shield nearly round, dorsal shield W 387 (376); D 1 and D 4 on small humps ( Fig. 9A View FIGURE 9 ). Dorsal humps underdeveloped ( Fig. 9C View FIGURE 9 ). Cauda and pygal lobes short; posteriorly with a rounded extension, on which the petiole is located. Petiole lance-shaped, without ligulate process ( Fig. 9A View FIGURE 9 ). Cx-I and Cx-II not exceeding anterior margin of idiosoma; medial margin of Cx-IV twice the length of Cx-III ( Fig. 9B View FIGURE 9 ). ACG medium L 181 (176); PCG medium L 218 (210); Gb–Cx-IV 314 (299); Gb–Gp 366 (354); Gb–Ep 462 (451); Ap extending to lateral margins of idiosoma ( Fig. 9B View FIGURE 9 ). IV-L-4 without a spur ( Fig. 9D View FIGURE 9 ). L of palp segments: P-II 51 (53), P-III 51 (52), P-IV 72 (65), P-V 41 (38) ( Fig. 9D View FIGURE 9 ); L of leg segments: L of I-L-1–6: 78 (70), 84 (76), 92 (85), 112 (106), 123 (116), 136 (130) ( Fig. 10A View FIGURE 10 ); L of II-L-1–6: 55 (51), 112 (100), 89 (93), 128 (132), 143 (156), 152 (143) ( Fig. 10B View FIGURE 10 ); L of III-L-1–6: 64 (57), 124 (131), 91 (80), 135 (127), 144 (135), 129 (135) ( Fig. 10C View FIGURE 10 ); L of IV-L-1–6: 91 (85), 149 (152), 117 (107), 159 (163), 163 (167), 168 (174) ( Fig. 10D View FIGURE 10 ).

Female (n=2; Figures 11–12 View FIGURE 11 View FIGURE 12 ): Idiosoma L 1064 (1003), W 953 (942), L/W ratio 1.12 (1.06) ( Fig. 11A View FIGURE 11 ); dorsal furrow complete, dorsal shield oval, L 840 (831), W 698 (684); D 1 on wide round humps ( Fig. 11A View FIGURE 11 ). Medial separation of Cx-IV almost equal in width with Gp ( Fig. 11B View FIGURE 11 ). Medial margin of Cx-III shorter than that of Cx-IV; ACG medium L 198 (186); PCG medium L 234 (230); Gb–Cx-IV 343 (329); Gb–Gp 402 (411); Gb–Ep 774 (740) ( Fig. 11B View FIGURE 11 ). Ap close to Cx-IV, long, straight or bowed, not extending to lateral margins of idiosoma, same wide along their total length ( Fig. 11B View FIGURE 11 ). Genital field longer than wide, Gp without sclerotized patches ( Fig. 11B View FIGURE 11 ). L of palp segments: P-I 40 (35), P-II 72 (65), P-III 54 (52), P-IV 77 (72), P-V 42 (45) ( Fig. 11C View FIGURE 11 ); L of leg segments: L of I-L-1–6: 55 (51), 111 (104), 92 (93), 128 (134), 134 (128), 136 (134) ( Fig. 12A View FIGURE 12 ); L of II-L-1–6: 55 (56), 128 (124), 108 (111), 148 (145), 156 (148), 152 (147) ( Fig.12B View FIGURE 12 ); L of III-L-1–6: 72 (74), 112 (121), 106 (110), 155 (148), 171 (159), 160 (163) ( Fig.12C View FIGURE 12 ); L of IV-L-1–6: 116 (113), 155 (152), 154 (152), 198 (183), 194 (197), 192 (184) ( Fig. 12D View FIGURE 12 ).

Habitat. Still water.

Distribution. China (Jilin); Palaearctic. Whole of Europe ( Gerecke et al. 2016).

Remarks. The whole idiosoma features, palp and cauda are almost the same as Arrenurus (Arrenurus) crassicaudatus ( Gerecke et al. 2016) , except for the medial separation of Cx-IV which is almost equal in width with Gp in the Chinese female specimen, but medial separation of Cx-IV wider than Gp in the European specimen Hence the specimens from Baicheng City, Jilin Province show a general conformity with that from Europe. The species is recorded for the first time for the Chinese fauna.