Atractides curtisetus, Smit, Harry & Pešić, Vladimir, 2014

Smit, Harry & Pešić, Vladimir, 2014, Water mites from Mount Kinabalu and the Crocker Range, Borneo, Malaysia (Acari: Hydrachnidia), with the description of 34 new species, Zootaxa 3876 (1), pp. 1-71 : 32-33

Atractides curtisetus n. sp.

( Figs. 18A–G )

Type series. Holotype female, dissected and slide mounted, Little Lumotok stream, Sayap, Mt Kinabalu, Borneo, Malaysia, 6º 0 9.467 N 116º 34.027 E, alt. 1069 m asl., 17-ix-2012 ( RMNH).

Diagnosis (Male unknown). Median sutures Cx-I short, posteromedial margin Cx-I+II rounded, P4 sword seta and ventral setae inserted far distally; I-leg little modified, setae S-1 and -2 homoiomorphic and short, enlarged in basal third, side by side, flagellar seta short and weakly modified, I-leg-6 nearly straight.

Description. Female. Integument dorsally striated, muscle insertions unsclerotized. Coxal field: Cx-I+II long and slender, posteromedial margin sharply rounded, Cx-II apodemes in an acute angle, Cx-III+IV slender, suture line Cx-III/IV in medial part nearly straight ( Fig. 18A ). Genital field: Ac in a curved line. Palp: ventral margin of P- 2 in the centre concave, slightly convex in the distal half, without extensions, P-3 slightly concave, P-4 nearly straight, sword seta and ventral setae inserted far distally ( Fig. 18D ). Legs: I-leg little modified, I-leg-5 with little diverging, straight dorsal and ventral margins, setae S-1 and -2 homoiomorphic and short, enlarged in basal third, side by side, flagellar seta short and weakly modified, I-leg-6 nearly straight, dorsal and ventral margins equally diverging from the base to the claw furrow, but with the typical setae groups, claw strong ( Fig. 18B ).

Measurements —Idiosoma length/width 628/446; coxal field: length 375; Cx-III width 400; Cx-I+II medial length 182, lateral length 273; genital field length/width 133/141, genital plates length 100–105; length Ac 1–3: 38–40, 38–41, 38.

Palp: Total length 253, dorsal length/height, dorsal length/height ratio: P1, 28/27, 1.03; P2, 55/38.5, 1.44; P3, 70/34, 2.1; P4, 74/21.5, 3.44; P5, 26/14, 1.9; length P2/P4 ratio 0.75. Capitulum length 134; chelicera total length 197, claw length 56, basal segment length 148, length basal segment/claw ratio 2.64.

Legs: I-leg-5 dorsal length 112, ventral length 91, dorsal length/ventral length ratio 1.23, maximum height 32, dorsal length/maximum height 3.47, S-1 length 34, length/width ratio 5.5, S-2 length 32, length/width ratio 4.8, distance S-1-2 0, length ratio S-1/2 1.05; I-leg-6 length 123, maximum height (HC sensu Gerecke 2003) 31, length/ central height ratio 4.0; length I-leg-5/6 ratio 0.91.

Male: unknown.

Etymology. Named for the short sword seta of I-leg-5.

Remarks. The new species is unique among Oriental representatives of the genus in the combination of P-4 sword and ventral setae placed far distally and a slightly modified I-leg, with terminal segments at first view appearing equal in shape to II/III-leg. Due to the unbowed terminal segment of I-leg the new species is similar to members of the subgenus Megabates K. Viets. However , as mentioned by Gerecke (2003), the latter character is described in many Atractides s. str. species, suggesting that most probably Megabates is a synonym of Atractides . Atractides (Megabates) orientalis ( Cook, 1967) differs in having short and stocky palp segments, with P-4 ventral setae inserted more proximally, capitulum with elongated and pointed rostrum, chelicerae with a long claw and a more stouter I-leg-5 and -6 (see Cook 1967).

Atractides chelidon Gerecke 2003 , a hyporheobiontic species, has a similar morphology of palp and I-L, but differs in the absence of lateral eyes, short median sutures Cx-I, and setae S-1 and -2 slender and more pointed (see Gerecke 2003).

Distribution. Borneo; known only from the locus typicus.

Figures

FIGURE 18 A – G. Atractides curtisetus n. sp., Little Lumotok stream, female holotype: A = idiosoma, ventral view; B = I-leg- 5 and - 6; C = I-leg- 5; D = palp, medial view; E = palp, lateral view; F = capitulum; G = chelicera. Scale bars = 100 Μm.