Arrenurus (Arrenurus) ancoralis Zheng & Gu & Guo & Zhang 2021, sp. nov.
Creators: name: Zheng, Yulin
name: Gu, Xinyao
name: Guo, Jianjun
name: Zhang, Runzhi
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Trombidiformes
Arrenuridae
Arrenurus
Arrenurus ancoralis

description: Arrenurus (Arrenurus) ancoralis Zheng & Guo sp. nov.
(Figs. 1–3)
Material examined: Holotype male, No. GD-AR-2002100301, stream, Dinghushan National Nature Reserve, Zhaoqing City, Guangdong Province, China (23°10’N, 112°31’E; alt. 1000 m), 3-X-2002, Jianjun Guo leg. Paratype, 0/1/0, No. GD-AR-2002100302, same data as holotype.
Diagnosis. D 3 on big humps and each with a small protrusion bearing D 3 gland; petiole well-developed, the median somewhat contracted and the end slightly enlarged. Ligulate process extending beyond posterior margin of petiole, and approximately triangle-shaped and nearly straight posteriorly in dorsal view.
Description. Male (n=1): Idiosoma L 1126 (including petiole), W 738, L/W ratio 1.5. Anterior margin of idiosoma slightly concave. Dorsal furrow incomplete, and not reaching to the middle of the pygal lobe’s dorsum; dorsal shield W 419, anterior margin nearly round (Fig. 1B). Dorsal humps well developed, directed upward, and with a small protrusion bearing D 3 gland near the top of each. Petiole well-developed, L 114, the median somewhat narrowed, and the end slightly widened in dorsal view; ligulate process extending beyond posterior margin of petiole, approximately triangle-shaped and almost straight posteriorly (Fig. 1C). ACG medium L 156; Gb–Cx-IV, 532; Gb–Gp, 593; Gb–Ep, 845; Cx-IV posterior angles undeveloped (Fig. 1A). Inverted T-shaped cuticular structure between the glands of D 4 undeveloped, only with horizontal ridge (Fig. 1D); Ap evenly extending from Gp to the sides of the body (Fig. 1A, 1C). L of palp segments: P-1, 30; P-2, 65; P-3, 53; P-4, 97; P-5, 67; P-2 with three dorsal setae; P-3 medially with two setae near anterior margin (Fig. 1E). L of I-L-1–6: 52, 124, 133, 164, 152, 179 (Fig. 2A). L of II-L-1–6: 56, 115, 135, 147, 161, 196. L of III-L-1–6: 54, 116, 150, 180, 174, 199. L of IV-L-1–6: 144, 200, 255, 342, 129, 114. Spur of IV-L-4 more than the half length of IV-L-5. Number of swimming setae: II-L-3 3, II-L-4 7, II-L-5 6; III-L-3 8 (Fig. 2B), III-L-4 9, III-L-5 7; IV-L-3 14 (Fig. 2C), IV-L-4 16 (including five short swimming setae on the spur), IV-L-5 9 (Fig. 2D).
Female (n=1): Female (n=1): Idiosoma L 1194, W 1042, L/W ratio 1.1; dorsal furrow complete; D 1 glands on the dorsal humps (Fig. 3B and C). Cx-I and Cx-II not extending beyond anterior margin of idiosoma. Medial margin of Cx-IV longer than medial margin of Cx-III. Posteromedial corner of Cx-IV rounded. Gp approximately heartshaped, L 137 and W 152 and flanked by relatively long wing shaped Ap. ACG medium L 190; Gb–Cx-IV, 495; Gb–Gp, 609; Gb–Ep, 944. Ap short, and narrow laterally towards the distal (Fig. 3A); L 137 and W 152; (Fig. 3A). L of palp segments: P-1, 17; P-2, 76; P-3, 55; P-4, 118; P-5, 57. P-2 medially with two setae near anterior margin (Fig. 3D). L of I-L-1–6: 52, 113, 156, 179, 167, 171 (Fig. 3E). L of II-L-1–6: 72, 144, 168, 197, 171, 190. L of III-L-1–6: 66, 132, 169, 173, 179, 189. L of IV-L-1–6: 120, 217, 217, 266, 194, 126. Number of swimming setae: II-L-3 3, II-L-4 8, II-L-5 7; III-L-3 8, III-L-4 9, III-L-5 7; IV-L-3 17, IV-L-4 15, IV-L-5 14 (Fig. 3F).
Habitat. Pool in the stream bed with dead branches and rotten leaves.
Etymology. Derived from the Latin word “ancorale” (anchor). In this new species, D 3 gland protrusion looks like an anchor.
Remarks. The new species is very similar to Arrenurus (Arrenurus) cuspidator Müller, 1776 (Viets 1936) in general shape of idiosoma and petiole, but differs from the new species in the following points: (1) Dorsal humps directed upwards in the new species, but is directed towards the anterior margin of idiosoma in A. (A.) cuspidator. (2) Hyaline membrane is not obvious in the new species, but obvious in A. (A.) cuspidator. (3) Caudal humps with V 2 and V 3 are developed, beyond the posterior margin of the body in the new species, but undeveloped in A. (A.) cuspidator. (4) The humps of D4 are wider in the new species than in A. (A.) cuspidator.
The new species is close to Arrenurus (Arrenurus) antalyensis Gülle, Boyaci & Gülle, 2011 (Yunus et al. 2013) collected from Turkey, but they differ from each other by the following: (1) The petiole end is slightly enlarged in the new species, but obviously enlarged in A. (A.) antalyensis. (2) Cx-I and Cx-II not extending to the anterior margin of idiosoma in the new species, but extending beyond the anterior margin of idiosoma in A. (A.) antalyensis. (3) Dorsal humps are directed upwards in the new species, while titled forwards the anterior of idiosoma in A. (A.) antalyensis. (4) The pygal lobes are well-developed in the new species, but small in A. (A.) antalyensis; (5) Ligulate process is relatively short in the new species, but elongated in A. (A.) antalyensis.
description: Published as part of Zheng, Yulin, Gu, Xinyao, Guo, Jianjun & Zhang, Runzhi, 2021, Two new species and one new record species of genus Arrenurus Dugès, 1834 (Acari, Hydrachnidia, Arrenuridae) from China, pp. 63-72 in Zootaxa 5072 (1) on pages 65-67, DOI: 10.11646/zootaxa.5072.1.7, http://zenodo.org/record/5729017