Atractides (Atractides) mangdensis, PešićK & SmitK & GurungK, 2023

PešićK, Vladimir, SmitK, Harry & GurungK, Mer Man, 2023, Five new species of water mite genus Atractides Koch, 1837 from Bhutan with new records (Acari: Hydrachnidia: Hygrobatidae), Acarologia 63 (1), pp. 148-168 : 152-155

Atractides (Atractides) mangdensis sp. nov.

Zoobank: F228834C-4255-4BC3-A7B9-58CB077B4F26

Figure 4

Type material — Holotype ♀, dissected and slide mounted ( NBC), Bhutan, MG5 Dakpay Chhu , 27.14621°N, 90.69220°E, 539 m asl, 1 May 2021.

Diagnosis — Female (male unknown) – Integument striated; muscle insertions unsclerotized; excretory pore smooth; Vgl-1 not fused to Vgl-2; genital plates short and stout flanking the postgenital sclerite, gonopore comparatively short, not exceeding genital plate length; P-2 with a pointed ventrodistal protrusion.

Description — Female – Integument dorsally striated, muscle insertions unsclerotized. Coxal field slender and longish, mediocaudal margin of Cx-I tongue-shaped ( Figure 4B). Genital plates short and stout flanking the postgenital sclerite, directed laterally, acetabula in triangular position ( Figure 4C). Excretory pore smooth; Vgl-1 not fused to Vgl-2. P-2 ventral margin straight, ending in a pointed ventrodistal protrusion, ventral margin of P-3 slightly concave, P-4 slender, insertions of ventral setae flanked by denticles, sword seta between ventral setae, nearer to distoventral seta ( Figure 4E). I-L-5 with S-1/2 slender, with knob-shaped tip, and close to each other; I-L-6 nearly straight, with strong claw ( Figure 4D).

Measurements — Idiosoma L 475, W 303; maximum diameter Dgl-4, 22. Coxal shield L 253; Cx-III W 244; Cx-I+II mL 111, Cx-I+II lL 178. Genital field L/W 97/122, genital plates

L 70, pregenital sclerite 48, gonopore L 63, L Ac-1-3: 28, 30, 36. Egg maximum diameter (n

= 2) 97-100.

Palp – Total L 302; dL/H, dL/H ratio: P-1, 23/23, 1.0; P-2, 70/48, 1.45; P-3, 78/44, 1.78;

P-4, 98/27, 3.67; P-5, 33/11, 3.0; L ratio P-2/P-4, 0.72. Gnathosoma vL 95; chelicera total L

152.

Legs– I-L-5 dL 123, vL 92, dL/vL ratio 1.33, maximum H 30, dL/maximum H 4.13, S-1 L

63, L/W ratio 10.6, S-2 L 55, L/W ratio 7.1, distance S-1-2, 7.0, dL ratio S-1/2, 1.13; I-L-6 dL

94, central H 17, dL/central H ratio 5.56; L I-L-5/6 ratio 1.31.

Male — Unknown.

Etymology — Named after the Mangde Chhu river.

Discussion — The new species belongs to the Atractides pygmaeus complex characterized by small dimensions (idiosoma L <500), unsclerotized excretory pore, slightly modified I-L-5/6 with short and bluntly pointed S-1/2 and the presence of well pronounced denticles accompanying the ventral setae of P-4 ( Gerecke 2003). In regard to unsclerotized muscle attachments, P-2 with a pointed ventrodistal protrusion and unfused Vgl-1/2 the new species is similar to A. manasi Pešić & Smit, 2018 , a species described on the basis of a single female from a stream in the Tien Shan Mountains in Kyrgyzstan ( Pešić and Smit 2018). The latter species differs from the new species from Bhutan by having a comparatively much longer gonopore, exceeding the genital plate length, and a comparatively shorter setae S-1/-2 (L S-1, 51, S-2, 44), shifted to each other. As mentioned in some other papers (see for example, Pešić et al. 2012 ; Pešić and Smit 2018), no particular sexual dimorphism is to be expected in the male of A. pygmaeus complex. Therefore, in regard to clear cut differences between examined specimens from Bhutan and Kyrgyzstan, description of the new species based on a female is justified.

Distribution — Bhutan ; known only from the type locality ( Figure 12C).