Monatractides phantasos, Pešić & Smit, 2014

Pešić, Vladimir & Smit, Harry, 2014, Torrenticolid water mites (Acari: Hydrachnidia: Torrenticolidae) from Malaysian Borneo, Zootaxa 3840 (1), pp. 1-72: 57

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Monatractides phantasos

n. sp.

Monatractides phantasos   n. sp.

( Figs. 30G View FIGURE 30 , 34A–G View FIGURE 34 , 35A–D View FIGURE 35 , 39F–G View FIGURE 39 , 40F–G View FIGURE 40 )

Type series. Holotype female, dissected and slide mounted, Malaysia, Borneo , stream Kemantis , Sayap, Mt Kinabalu, 6º09.841 N, 116º33.936 E, alt. 928 m asl., 16.ix.2012 Smit GoogleMaps   . Paratypes: one male, Great Lumotok stream, Mt Kinabalu, 6º09.336 N, 116º34.056 E, alt. 1087 m asl., 17.ix.2012 Smit, dissected and slide mounted GoogleMaps   .

Diagnosis. Idiosoma elongated-oval (dorsal shield L/W ratio 1.3); frontal plates broad (L/W ratio 1.4), shorter than shoulder plates (shoulder/frontal plate L ratio 1.3); gnathosomal bay V-shaped; ventral setae on P-4 short. Male: medial margin of Cx-II/III relatively short; ejaculatory complex conventional in shape with small proximal chamber.


General features —Idiosoma elongated-oval; frontal plates broad ( Fig. 34B View FIGURE 34 ), shorter than shoulder plates; frontal margin medially slightly convex, between flat, anterolaterally pointed protrusions ( Figs. 34A View FIGURE 34 , 35A View FIGURE 35 ); Cxgl-4 located far anteriorly, near tips of Cx-I; gnathosomal bay V-shaped, proximally pointed ( Figs. 34C View FIGURE 34 , 12C View FIGURE 12 ); suture line of Cx-IV distinct, originating from the lateral edge of the genital field and extending posteriorly beyond the posterior margin of the genital field; excretory pore and Vgl-2 away from the line of primary sclerotization, Vgl-2 slightly posterior to excretory pore; gnathosoma with long dorsal apodemes, rostrum truncated ( Fig. 34G View FIGURE 34 ); P-2 and P-3 distal margins without pointed tips, P-4 ventral setae short, not reaching the tip of P-5, with small denticles near insertion ( Figs. 34D–E View FIGURE 34 ). Male: medial margin of Cx-II/III relatively short; genital field subrectangular; ejaculatory complex: proximal and distal arms well developed, carina anterior long, proximal chamber small ( Fig. 30G View FIGURE 30 ). Female: genital field large and pentagonal in shape, anteriorly enlarged, laterally slightly convex, tapering posteriorly.


Female (holotype)—Idiosoma (ventral view: Fig. 40F View FIGURE 40 ) L 813, W 647; dorsal shield ( Figs. 34B View FIGURE 34 , 39F View FIGURE 39 ) L 741, W 572, L/W ratio 1.3; dorsal plate L 641; shoulder plate L 211–213, W 103, L/W ratio 2.05–2.06; frontal plate L 166, W 116, L/W ratio 1.43, L shoulder/frontal plate ratio 1.27–1.28. Gnathosomal bay L 111, Cx-I total L 289, Cx-I mL 178, Cx-II+III mL 43; ratio Cx-I L/Cx-II+III mL 6.7; Cx-I mL/Cx-II+III mL 4.1. Genital field L/W 198/175, ratio 1.13; distance genital field-excretory pore 163, genital field-caudal idiosoma margin 275. Gnathosoma vL 154; palp: total L 184, dL/H, dL/H ratio: P-1, 29/21-22, 1.36; P-2, 47/33.5, 1.4; P-3, 35/28, 1.28; P-4, 48/20, 2.4; P-5, 25/11–12, 2.1; P-2/P-4 ratio 0.98. Legs: dL of I-L-2–6: 68, 72, 91, 100, 103, I-L-6 H 37, dL/H I-L-6 ratio 2.8.

Male (paratype)—Idiosoma (ventral view: Fig. 40G View FIGURE 40 ) L 781, W 634; dorsal shield ( Figs. 35B View FIGURE 35 , 39G View FIGURE 39 ) L 725, W 556, L/W ratio 1.3; dorsal plate L 640; shoulder plate L 213–222, W 100–109, L/W ratio 2.0–2.1; frontal plates fused to form an elongated platelet, L/W 319/123, ratio 2.6. Gnathosomal bay L 116, Cx-I total L 288, Cx-I mL 172, Cx-II+III mL 72; ratio Cx-I L/Cx-II+III mL 4.0; Cx-I mL/Cx-II+III mL 2.34. Genital field L/W 163/138, ratio 1.18; ejaculatory complex L 228; distance genital field-excretory pore 158, genital field-caudal idiosoma margin 256. Palp: total L 187, dL/H, dL/H ratio: P-1, 30–31/21, 1.45; P-2, 49/34, 1.45; P-3, 35/26, 1.35; P-4, 48/19, 2.6; P5, 25/11, 2.3; P-2/P-4 ratio 1.02. Legs: dL of I-L-2-6: 65, 72, 88, 97, 99, I-L-6 H 36, dL/H I-L-6 ratio 2.8.

Etymology. The species is named after Phantasos (Ancient Greek: Φάντασος) who was a spirit of dreams of fantasy, and who takes the shape of inanimate objects. The species name is a noun in apposition (in the nominative case), despite the Recommendation 31A of the ICZN (1999) about avoidance of personal names as nouns in appositions, because there is no case for it being confusing or misleading.

Discussion. The combination of a broad frontal plates (L/W ratio 1.4) and moderately deep, V-shaped, gnathosomal bay, easily separates the new species from all other members of the genus. Due to the V-shaped, gnathosomal bay, Monatractides phantasos   n. sp. somehow resembles M. oxystomus (K. Viets, 1935)   and M. tobaensis (K. Viets, 1935)   (see above). However these two species seem not to be closely related to the new species as they differ in a series of features: less broader frontal plates, frontal margin medially strongly concave between large anterolaterally pointed protrusions, gnathosomal bay more deep, moderately long medial margin of Cx-II/III, P-4 with long ventral seta exceeding distal edge and excretory pore and Vgl-2 shifted more away from the line of primary sclerotization.

Variability. Frontal plates in male fused to form an elongated platelet, but traces of fusion visible ( Figs. 35B View FIGURE 35 , 39G View FIGURE 39 ).

Habitat. Sandy/bouldery streams, shaded by rain forest ( Fig. 43D View FIGURE 43 ).

Distribution. Borneo.