Arrenurus (Arrenurus) yanchengensis, 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 : 62-63

Arrenurus (Arrenurus) yanchengensis sp. nov.

( Figs 7–8 )

Material examined. Holotype male, GUGC, Slide No. JS-AR-2018072701, Yancheng City , Jiangsu Province, P. R. China (33°37′76″N, 120°13′99″E; alt. 5 m), 27-VII-2018, Zhuhui Ding leg.. 1/0/0.

Diagnosis. Hyaline membrane short and extending to the base of the pygal lobes; pygal lobes well developed, posteriorly almost at the same level as posteror margin of petiole; D 4 on a small hump, flanked by two connected small humps.

Description. Male (n=1; Figures 7–8 ): Idiosoma L 973 (including petiole), W 718, L/W ratio 1.36 ( Fig. 7A ). Anterior margin of idiosoma slightly concave ( Fig. 7A ). Dorsal furrow incomplete, dorsal shield W 450; D 1 on small humps ( Fig. 7A ). Pygal lobes well developed, posteriorly, almost at the same level as posterior margin of petiole. Hyaline membrane short and extending to the base of the pygal lobes ( Fig. 7A ). Petiole L 99, approximately rectangular; ligulate process bottle-shaped, lying anterior to posterior margin of petiole ( Fig. 7A ). In lateral view, the dorsal humps small ( Fig. 7C ). Cx-I and Cx-II not extending beyond anterior margin of idiosoma; medial margin of Cx-IV twice the length of the medial margin of Cx-III ( Fig. 7B ). ACG medium L 218; PCG medium L 234; Gb–Cx-IV 412; Gb–Gp 478; Gb–Ep 619; Ap enlarged at the Gp, extending to lateral margins of idiosoma, lateral parts narrower; Ap with two pairs of genital setae ( Fig. 7B ). D 4 on a small hump near the petiole, flanked by two connected small humps ( Fig. 7A ). L of palp segments: P-I 25, P-II 60, P-III 49, P-IV 73, P-V 43 ( Fig. 7D ), P-2 with two ventral setae; L of leg segments: L of I-L-1–6: 55, 96, 102, 128, 129, 182 ( Fig. 8A ); L of II-L-1–6: 60, 108, 123, 156, 157, 204 ( Fig. 8B ); L of III-L-1–6: 90, 134, 121, 164, 164, 184 ( Fig. 8C ); L of IV-L-1–6: 116, 181, 183, 263, 101, 144 ( Fig. 8D ).

Female. unknown.

Habitat. streams.

Distribution. China (Jiangsu).

Etymology. Named after Yancheng City, where the type specimen was collected.

Remarks. The new species is similar to Arrenurus (Arrenurus) angelieri Cassagne-Méjean, 1966 ( Gerecke et al. 2016). However, the new species differs from A. (A.) angelieri in the following points: (1) Hyaline membrane short and extending to the base of the pygal lobes in the new species, but not extending laterally in A. (A.) angelieri ; (2) without ligulate process in the new species, but with a short ligulate process in A. (A.) angelieri ; (3) Ap extending to lateral margins of idiosoma in the new species, but not extending laterally in A. (A.) angelieri ; (4) posterior margin of petiole concave in A. (A.) angelieri , but convex in the new species.

Figures

FIGURE 7. Arrenurus (Arrenurus) yanchengensis sp. nov., male: A = Idiosoma, ventral view; B = Idiosoma, dorsal view; C = Idiosoma, dorsolateral view; D = Palp. Scale bars: A B C =200 um, D = 100 μm.

FIGURE 8. Arrenurus (Arrenurus) yanchengensis sp. nov., male: A = I-L; B = II-L; C = III-L; D = IV-L. Scale bars: A B C D = 100 um.