Monatractides sahuli, Pešić, Vladimir & Smit, Harry, 2011

Pešić, Vladimir & Smit, Harry, 2011, Water mites of the genus Monatractides Viets (Acari: Hydrachnidia, Torrenticolidae) from New Guinea, with descriptions of nine new species, Zootaxa 2779, pp. 39-62 : 53-55

Monatractides sahuli sp. nov.

( Figs. 12 – 13 )

Type series. Holotype, male, dissected and slide mounted; Indonesia, New Guinea, Papua Province, unnamed creek crossing road to Pass Valley, 13.iii.2010, 3˚ 52.849 S 139˚ 04.194 E, 2253 m a.s.l. Paratypes: 1/4 (0/1 mounted), same data as holotype.

Diagnosis. The shoulder and frontal platelets of each side are fused to each other to form a pair of elongated platelets; the area of primary sclerotization of the dorsal plate with four dorsoglandularia; capitular bay rounded at its proximal end; P-4 with well developed tubercles near the insertion of the ventral hairs; postgenital area large; excretory pore on the line of primary sclerotization, Vgl-2 posterior and well away from the excretory pore.

Description. Male: Idiosoma (ventral view: Fig. 12B ) L 938, W 777; dorsal shield ( Fig. 12A ) L 822, W 672, L/W ratio 1.22; dorsal plate 769; the shoulder and frontal platelets of each side are fused to each other to form a pair of elongated platelets, L 378, W 109, L/W ratio 3.5; capitular bay L 205, W 82, L/W ratio 2.5; Cx-1 total L 335, Cx-1 medial L 130, Cx-2+3 medial 31; ratio Cx-1 L/Cx-2+3 medial L 10.8; Cx-1 medial L/Cx-2+3 medial L 4.2; genital field L/W 209/156, L/W ratio 1.34; ejaculatory complex ( Fig. 13F ) L 225; distance genital field–excretory pore 163, genital field–caudal idiosoma margin 350; capitulum ( Fig. 13E ) ventral L 212; chelicera total L 269; palp ( Figs. 13B – C ) total L 257, L and %L (in parentheses): P-1, 27 (10.5); P-2, 76 (30.0); P-3, 51 (19.8); P-4, 71 (27.6); P-5, 32 (12.5); L P-2/P-4 ratio, 1.07; L I-L-4-6 ( Fig. 13D ): 115, 141, 142.

Female: Idiosoma (ventral view: Fig. 13A ) L 1022, W 906; dorsal shield L 881, W 756, L/W ratio 1.17; dorsal plate 831; the shoulder and frontal platelets of each side are fused to each other to form a pair of elongated platelets, L 372, W 113, L/W ratio 3.3; capitular bay L 214, W 83, L/W ratio 2.58; Cx-1 total L 333, Cx-1 medial L 119, Cx-2+3 medial 18; ratio Cx-1 L/Cx-2+3 medial L 18.5; Cx-1 medial L/Cx-2+3 medial L 6.6; genital field L/W 231/195, L/W ratio 1.19; distance genital field–excretory pore 184, genital field–caudal idiosoma margin 428; capitulum ventral L 225; chelicera total L 289; palp total L 278, dL and %L (in parentheses): P-1, 32 (11.5); P-2, 83 (30.0); P-3, 52 (18.7); P-4, 77 (27.7); P-5, 34 (12.2); P-2/P-4 ratio, 1.08; L I-L-4-6: 125, 146, 150.

Etymology. The species is named after the Sahul Shelf.

Discussion. Monatractides sahuli sp. nov. is distinguished from all other New Guinean species of the genus by the shoulder and frontal platelets of each side being fused to each other. This character is also found in several other species of Monatractides : M. acutiscutatus ( Viets, 1913) from Cameroon ( Viets 1913), M. hesperia ( Lundblad, 1941) from Colombia ( Lundblad 1941) and M. veracruzensis ( Cook, 1980) from Mexico ( Cook 1980). K. Viets (1931) proposed the subgenus ‘ Rusetriella ’ for these species, which has been rejected by Wiles (1997b) based on phylogenetic analysis.

Monatractides sahuli sp. nov. can be easily distinguished by the shape of the capitular bay which is more rounded at its proximal end and the presence of four dorsoglandularia in the area of primary sclerotization of the dorsal plate vs. the more pointed, V-shaped capitular bay and the area of primary sclerotization of the dorsal plate with two dorsoglandularia in the three aforementioned species.

Distribution. New Guinea.

Figures

FIGURE 12 A – B. Monatractides sahuli sp. nov., male: A = dorsal shield; B = ventral shield. Scale bar = 100 µm.

FIGURE 13 A – F. Monatractides sahuli sp. nov. (D – F = male, A = female): A = ventral shield; B = palp, lateral view; C = palp, medial view; D = I-L- 5 and - 6; E = capitulum and chelicera; F = ejaculatory complex. Scale bars = 100 µm.