Arrenurus (Arrenurus) crassicaudatus Kramer 1875
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 crassicaudatus

description: Arrenurus (Arrenurus) crassicaudatus Kramer, 1875
(Figs 9–12)
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 .. 2/2/0.
Description. Male (n=2; Figures 9–10): Idiosoma L 714 (725) (including petiole), W 588 (574), L/W ratio 1.21 (1.26) (Fig. 9A). Anterior margin of idiosoma slightly concave (Fig. 9A). 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). Dorsal humps underdeveloped (Fig. 9C). Cauda and pygal lobes short; posteriorly with a rounded extension, on which the petiole is located. Petiole lance-shaped, without ligulate process (Fig. 9A). Cx-I and Cx-II not exceeding anterior margin of idiosoma; medial margin of Cx-IV twice the length of Cx-III (Fig. 9B). 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). IV-L-4 without a spur (Fig. 9D). L of palp segments: P-II 51 (53), P-III 51 (52), P-IV 72 (65), P-V 41 (38) (Fig. 9D); L of leg segments: L of I-L-1–6: 78 (70), 84 (76), 92 (85), 112 (106), 123 (116), 136 (130) (Fig. 10A); L of II-L-1–6: 55 (51), 112 (100), 89 (93), 128 (132), 143 (156), 152 (143) (Fig. 10B); L of III-L-1–6: 64 (57), 124 (131), 91 (80), 135 (127), 144 (135), 129 (135) (Fig. 10C); L of IV-L-1–6: 91 (85), 149 (152), 117 (107), 159 (163), 163 (167), 168 (174) (Fig. 10D).
Female (n=2; Figures 11–12): Idiosoma L 1064 (1003), W 953 (942), L/W ratio 1.12 (1.06) (Fig. 11A); dorsal furrow complete, dorsal shield oval, L 840 (831), W 698 (684); D 1 on wide round humps (Fig. 11A). Medial separation of Cx-IV almost equal in width with Gp (Fig. 11B). 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). Ap close to Cx-IV, long, straight or bowed, not extending to lateral margins of idiosoma, same wide along their total length (Fig. 11B). Genital field longer than wide, Gp without sclerotized patches (Fig. 11B). 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); L of leg segments: L of I-L-1–6: 55 (51), 111 (104), 92 (93), 128 (134), 134 (128), 136 (134) (Fig. 12A); L of II-L-1–6: 55 (56), 128 (124), 108 (111), 148 (145), 156 (148), 152 (147) (Fig.12B); L of III-L-1–6: 72 (74), 112 (121), 106 (110), 155 (148), 171 (159), 160 (163) (Fig.12C); L of IV-L-1–6: 116 (113), 155 (152), 154 (152), 198 (183), 194 (197), 192 (184) (Fig. 12D).
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.
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 64-66, DOI: 10.11646/zootaxa.5174.1.4, http://zenodo.org/record/6973058