Monatractides phobetor, Pešić & Smit, 2014

Pešić, Vladimir & Smit, Harry, 2014, Torrenticolid water mites (Acari: Hydrachnidia: Torrenticolidae) from Malaysian Borneo, Zootaxa 3840 (1), pp. 1-72 : 59-60

Monatractides phobetor n. sp.

( Figs. 30H , 36A–G , 39H , 40H )

Type series. Holotype male, dissected and slide mounted, Malaysia, Borneo , Little Lumotok stream, Sayap, Mt Kinabalu, 6º09.467 N, 116º34.027 E, alt. 1069 m asl., 17.ix.2012 Smit.

Diagnosis. Male. Idiosoma elongated (dorsal shield L/W ratio 1.4); frontal and shoulder plates fused with the large dorsal plate forming an undivided dorsal shield; gnathosomal bay V-shaped, proximally pointed, three pairs of knob-like protrusions at the lateral margins of gnathosomal bay; medial margin of Cx-II/III relatively long.

Description

Male. General features —Idiosoma elongated; frontal and shoulder plates fused with the large dorsal plate forming an undivided dorsal shield ( Fig. 36A ); frontal margin medially slightly convex, between flat protrusions ( Fig. 36C ); gnathosomal bay V-shaped, proximally pointed, three pairs of knob-like protrusions at the lateral margins of gnathosomal bay; medial margin of Cx-II/III relatively long; genital field subrectangular; ejaculatory complex ( Fig. 30H ) normal in shape (proximal and distal arms and proximal chamber well developed); suture line of Cx-IV distinct, originating from lateral edge of genital field; excretory pore and Vgl-2 well separated from the line of primary sclerotization, Vgl-2 slightly posterior to excretory pore; gnathosoma elongated in lateral view, rostrum truncated ( Fig. 36F ); P-2 shorter than P-4, distal margin of P-3 and P-4 medially and laterally with several pointed extensions; P-4 with two ventral setae, one very long and away from distal edge ( Figs. 36D–E ).

Measurements —Idiosoma (ventral view: Figs. 36B , 40H ) L 727, W 553; dorsal shield ( Figs. 36A , 39H ) L 688, W 505, L/W ratio 1.36. Gnathosomal bay L 106, Cx-I total L 266, Cx-I mL 160, Cx-II+III mL 113; ratio Cx-I L/ Cx-II+III mL 2.35; Cx-I mL/Cx-II+III mL 1.4. Genital field L/W 146/120, ratio 1.21; ejaculatory complex L 168; distance genital field-excretory pore 144, genital field-caudal idiosoma margin 200. Gnathosoma vL 137; chelicera total L 160; palp total L 191, dL/H, dL/H ratio: P-1, 27/21, 1.3; P-2, 46/35, 1.32; P-3, 35/28, 1.46; P-4, 51/19, 2.67; P-5, 32/13.5, 2.4; P-2/P-4 ratio 0.91. Legs: dL of I-L-2-6: 55, 65, 79, 77, 85, I-L-6 H 29, L/H I-L-6 ratio 2.9.

Female: unknown

Etymology. The species is named after Phobetor (Ancient Greek: Φοβήτωρ) who was a spirit of nightmares and who takes the shape of animals. 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. Monatractides phobetor n. sp is closely related to M. synaptus (K. Viets, 1935) , M. amabilis ( Lundblad, 1941) and M. magnipharynx ( Lundblad, 1941) , all known from Java (K. Viets 1935, Lundblad 1971) characterized by the fusion of both frontal and shoulder platelets with the large dorsal plate. Due to the slender ventral setae on P-2 and P-3 the new species resembles M. amabilis (and differs from the two other species in having a denticle-like ventral seta on P-2 and -3). The new species can easily be distinguished from all abovementioned species by having V-shaped, proximally pointed gnathosomal bay with three pairs of knob-like protrusions at its lateral margins.

Habitat. Sandy/bouldery stream, shaded by rain forest.

Distribution. Borneo; known only from the locus typicus.

Figures

FIGURE 30A–M. Photographs of ejaculatory complex. A Monatractides longiventris (K. Viets, 1939), Mahua stream. B M. oxystomus (K. Viets, 1935), Kipungit River. C–D M. cf. macroporus (K. Viets, 1935): C = stream Bansadon Trail; D = Little Lumotok stream. E–F M. epiales n. sp., Kipungit River: E = holotype; F = paratype. G M. phantasos n. sp., Great Lumotok stream. H M. phobetor n. sp., Little Lumotok stream. I–L M. morpheus n. sp. I = holotype, small stream Layang Layang; K = Kemantis stream; K = Little Lumotok stream. M M. heracles n. sp., Little Lumotok stream.

FIGURE 36A–G. Monatractides phobetor n. sp., holotype male, Little Lumotok stream: A = dorsal shield; B = idiosoma, ventral view; C = frontal margin of idiosoma, dorsal view; D = palp, lateral view; E = P-4, medial view; F = gnathosoma, G = I-L-5 and -6. Scale bars = 100 µm.

FIGURE 39A–I. Photographs of dorsal shield. A–E Monatractides morpheus n. sp. (A–C stream Layang Layang; D–E Little Lumotok stream): A = male holotype; B = female paratype, C = female paratype; D = male, E = female. F–G M. phantasos n. sp: C = female holotype, Kemantis stream; G = male paratype, Great Lumotok stream. H M. phobetor n. sp., male holotype, Little Lumotok stream. I M. minuta n. sp., female holotype, Great Lumotok stream.

FIGURE 40A–I. Photographs of ventral shield. A–E Monatractides morpheus n. sp. (A–C stream Layang Layang; D–E Little Lumotok stream): A = male holotype; B = female paratype, C = female paratype; D = male, D = female. F–G M. phantasos n. sp: C = female holotype, Kemantis stream; G = male paratype, Great Lumotok stream. H M. phobetor n. sp., male holotype, Little Lumotok stream. I M. minuta n. sp., female holotype, Great Lumotok stream.