Monatractides sichuanensis Gu & Guo, 2020

Gu, Xin-Yao, Jia, Lan, Jin, Dao-Chao & Guo, Jian-Jun, 2020, Contributions to Chinese fauna of Torrenticolidae Piersig, 1902 (Acari, Hydrachnidia), with the description of three new species, ZooKeys 955, pp. 97-111 : 97

Monatractides sichuanensis Gu & Guo sp. nov. Figures 5 , 6

Material examined.

Holotype: ♀ (SC-TO-20160703), Anzihe National Nature Reserve, Chongzhou, Sichuan Province, P. R. China (30°47'43"N, 103°12'36"E, 1690 m a.s.l.), collected by Zhuhui Ding, 29-VII-2016. Paratype: 1 ♀ (SC-TO-20160704), same data as holotype.

Diagnosis.

Infracapitular bay U-shaped and wide; the tip of Cx-I with a papillary cuticular extension, E4 at the same level as the posterior margins of Gf; V1 fused with the line of primary sclerotization; D2 on the same level with muscle scars; dorsal and ventral apodemes of gnathosoma slender and sharp; dorsal seta on P-1 long.

Description.

Female (n = 2): Idiosoma elliptical, L 749 (715), W 497 (469), L/W ratio 1.5 (1.5). Dorsal plate 4+1 (Fig. 5A ), dorsal shield L 628 (586), W 438 (536), dorsal plate L 584 (423), frontal platelets L 118 (120), W 57 (68), shoulder platelets L 174 (157), W 80 (75). Infracapitular bay U-shaped and wide, depth 171 (163); the margins of Cx-II and Cx-III blunt and flat, the tip of Cx-I with a papillary cuticular extension, Cx-I L 292 (266), mL 123 (102), Cx-II+III mL 46 (31); Gf pentagonal, L 156 (159), W 122 (109), L/W ratio 1.3 (1.5), genital flaps with six pairs of setae at the margins; distance between Gf and Ap 222 (181); E4 at the same level as the posterior margins of Gf; V1 fused with the line of primary sclerotization, Ap at the same line with V2 (Fig. 5B ). Gnathosoma (Fig. 5D ) vL 182 (177), dL 177 (116); dorsal and ventral apodemes slender and sharp; claw short, chelicera bs L 159 (162), claw L 27 (22). P-1 with one long dorsal seta; P-2 with three dorsal and one ventral setae; P-3 with two long dorsal setae and one short ventral seta; P-4 with one short dorsal seta and two mediodistal setae (Fig. 5C ). dL of palp segments: P-1, 21 (25); P-2, 52 (48); P-3, 34 (32); P-4, 34 (39); P-5, 17 (14). Legs (Fig. 6 ): dL of leg segments: I-L-1-6: 57 (46), 70 (71), 59 (62), 67 (80), 58 (72), 79 (83); II-L-1-6: 55 (61), 92 (85), 56 (60), 86 (75), 84 (92), 108 (96); III-L-1-6: 63 (51), 99 (92), 71 (69), 94 (95), 118 (112), 120 (115); IV-L-1-6: 113 (115), 97 (87), 115 (111), 138 (140), 151 (126), 144 (142).

Male. Unknown.

Habitat.

Streamlet.

Remarks.

This new species is similar to Monatractides harveyi Pešić & Smit, 2012 ( Pešić and Smit 2012) in the general shape of gnathosoma, but differs in: (1) P-4 with small denticles near the insertion of the ventral setae in M. harveyi , but smooth in the new species; (2) the margins of Cx-II and Cx-III sharp in M. harveyi , but blunt and flat in the new species; (3) D2 anterior to muscle scars in M. harveyi , but D2 on the same level with muscle scars in the new species.

Etymology.

This new species is named after Sichuan Province, where it was collected.

Distribution.

China (Sichuan).

Figures

Figure 5. Monatractides sichuanensis Gu & Guo, sp. nov., female A dorsal view B ventral view C palp, lateral view D infracapitulum and chelicera. Scale bars: 100 μm.

Figure 6. Monatractides sichuanensis Gu & Guo, sp. nov., female A leg-I B leg-II C leg-III D leg-IV- 1 - 4 E leg-IV- 5, 6. Scale bar: 100 μm.