Monatractides (Monatractides) harveyi, Pešić, Vladimir & Smit, Harry, 2012

Pešić, Vladimir & Smit, Harry, 2012, Water mites of the genus Monatractides (Acari: Hydrachnidia, Torrenticolidae) from Australia, with descriptions of four new species, Zootaxa 3248, pp. 1-24 : 17-19

Monatractides (Monatractides) harveyi sp. nov.

( Figs. 10–11 , 14I )

Type material. Holotype male, dissected and slide mounted, Northern Terrıtory, Barramundie Creek, downstream of Plunge Pool, Kakadu NP, 13º 19.036 S 132º 26.279 E, 28.ix.2005 ( NTM). Paratypes: 1/5/0, same data as holotype, two females dissected and slide mounted; Northern Territory: Barramundie Creek, Kakadu NP, 24.vii.1994 2/ 1/0 ( NTM, 1/0/0 mounted); Pool Twin Falls, Kakadu NP, 23.vii.1994 1/0/0 ( NTM, mounted); South Alligator River at crossing with Gunlom Road, Kakadu NP, 13º 29.704 S 132º 28.601 E, 30.ix.2005, 2/2/0 ( RMNH, 1/0/0 mounted); Umbrawarra Gorge, Umbrawarra Gorge Nature Park, 13º 57.892 S 131º 41.620 E, 01.x.2005 2/0/0 ( RMNH); Western Australia, Miner’s Pool, Drysdale River Homestead, The Kimberley, 14.ix.1998 2/0/0 ( WAM, 1/0/0 mounted).

Further records. Northern Terrıtory: Florence Creek downstream of Florence Falls, Litchfield NP, 13º 05.885 S 130º 46.999 E, 25.xi.2005 2/0/0; 17 Mile Creek, Nitmiluk NP, 14º 18.318 S 132º 25.293 E, 04.x.2005 1/0/0; Kambolgie Creek, Kakadu NP, 13º 30.169 S 132º 23.688 E, alt. 96 m asl, 30.ix.2005 1/1/0; Outlet Upper Pool, Edith Falls, Katherine Gorge NP, 30.vii.1994 2/1/0 (1/1/0 mounted); Katherine River S of visitor center, Nitmiluk NP, 14º 19.472 S 132º 24.804 E, 02.x.2005 1/1/0; Katherine River near visitor center, Katherine Gorge NP, 28.vii.1994 1/0/0.

Diagnosis. Area of primary sclerotization of the dorsal plate extended; suture of Cx-4 not distinct; excretory pore in a medioposterior indentation of primary sclerotization, Vgl–2 posterior to excretory pore; distal margins of P-2 and -3 without denticles, P-4 with small denticle near the insertion of the ventral hairs, ventral seta on P-4 slen- der and short; I-L-6 relatively stout (L/H ratio 2.4–2.6). Male: genital field relatively large (L ratio genital field/ idiosoma 0.24–0.25); postgenital area short (ratio postgenital L/idiosoma L 19–20%); excretory pore embedded in the area of primary sclerotization. Female: excretory not embeded in the area of primary sclerotization.

Description. Male (holotype, in parentheses specimen from South Alligator River, Northern Territory, in square brackets specimen from Miner’s Pool, Western Australia): Idiosoma (ventral view: Fig. 10B ) L 681 (672) [768], W 500 (519) [625]; dorsal shield ( Fig. 10A ) L 581 (575) [663], W 425 (450) [525], L/W ratio 1.37 (1.28) [1.26]; dorsal plate 544 (534) [619]; shoulder plate L 172–182 (159–163) [188–197], W 59–61 (58–59) [78], L/W ratio 2.9–3.0 (2.74–2.76) [2.4–2.5]; frontal plate L 125–130 (127) [141–144], W 54–56 (59) [69–70], L/W ratio 2.2–2.4 (2.15) [2.04–2.05]; shoulder/frontal plate L ratio 1.38–1.4 (1.25–1.28) [1.33–1.37]; colour pattern as illustrated in Fig. 14I ; capitular bay L 160 (155) [172], W 52 (53) [64], L/W ratio 3.1 (2.9) [2.7]; Cx-1 total L 284 (278) [313], Cx-1 medial L 122 (123) [138], Cx-2+3 medial 81 (84) [97]; ratio Cx-1 L/Cx-2+3 medial L 3.5 (3.3) [3.2]; Cx-1 medial L/Cx-2+3 medial L 1.5 (1.46) [1.42]; genital field L/W 172 (172) [188]/138 (141) [156], L/W ratio 1.25 (1.22) [1.21]; ejaculatory complex normal in shape, L 225 (251) [291]; distance genital field–excretory pore 83 (83) [80], genital field–caudal idiosoma margin 129 (123) [155]; capitulum ( Fig. 10E ) ventral L 186 (184) [203]; chelicera total L 242 (240) [272]; palp ( Figs. 10F–G ): total L 205 (206) [234], dL: P-1, 29 (29) [31]; P-2, 62 (63) [73]; P-3, 39 (40) [46]; P-4, 57 (57) [66]; P-5, 18 (17) [18]; P-2/P-4 ratio 1.09 (1.1) [1.1]; L I-4-6 ( Fig. 10C ): 112 (109) [131], 114 (116) [131], 113 (112) [123]; I-L-6 L/H 2.57 (2.5) [2.51].

Female (paratype, n = 2; in parentheses some measurements of the specimen from Outlet Upper Pool, Northern Terrıtory): Idiosoma (ventral view: Fig. 11C ) L 797–825 (797), W 633–637 (613); dorsal shield ( Fig. 11B ) L 681–704, W 488–544, L/W ratio 1.3–1.4; dorsal plate 638–659; shoulder plate L 177–189, W 63–74, L/W ratio 2.55–2.8; frontal plate L 139–143, W 59–68, L/W ratio 2.1–2.4; shoulder/frontal plate L ratio 1.25–1.33; colour pattern as in male; capitular bay L 169–181 (181), W 59–63 (67), L/W ratio 2.7–3.07 (2.7); Cx-1 total L 313–315 (316), Cx-1 medial L 134–144 (134), Cx-2+3 medial 42–43 (37); ratio Cx-1 L/Cx-2+3 medial L 7.3–7.45 (8.5); Cx-1 medial L/Cx-2+3 medial L 3.1–3.4 (3.6); genital field L/W 183–188 (181)/159–169 (159), L/W ratio 1.11– 1.15 (1.14); distance genital field–excretory pore 170–175 (159), genital field–caudal idiosoma margin 247–275 (255); capitulum ventral L 204–219 (201); chelicera total L 266–278; palp: total L 221–233, dL: P-1, 35–37 (35); P-2, 64–70 (66); P-3, 43–46 (44); P-4, 58–62 (60); P-5, 19 (19); P-2/P-4 ratio 1.1–1.2 (1.1); L I-4-6: 115–123, 120– 126, 116–122; I-L-6 L/H 2.4–2.55.

Discussion. The male of Monatractides harveyi sp. nov. can be distinguished from other Australian members of the genus by the combination of the relatively larger extension of the genital field (L ratio genital field/idiosoma 0.24–0.26), the shortened postgenital area (18–20 % of the total idiosoma L), the excretory pore embedded in the area of primary sclerotization and the relatively long ejaculatory complex (L> 220 µm). Females can be separated from other known Australian Monatractides species on the basis of the colour pattern and the indistinct posterior suture line of Cx-4.

The male specimens from Western Australia differ in larger idiosoma and gnathosoma dimensions. In all other important diagnostic features these specimens are in good agreement with the type specimens from Northern Territory.

Etymology. Named after Dr Mark Harvey (Perth).

Distribution. Australia: Northern Territory, Western Australia (present study).

Figures

FIGURE 10 A – G. Monatractides harveyi sp. nov., male, Barramundie Creek (NT): A = dorsal shield; B = ventral shield; C = I- L- 4 - 6; D = anterodorsal portion of ventral shield; E = capitulum and chelicera; F = palp, medial view; G = palp, lateral view. Scale bars = 100 μm.

FIGURE 11 A – C. Monatractides harveyi sp. nov., female, Barramundie Creek (NT): A = anterodorsal portion of ventral shield; B = dorsal shield; C = ventral shield. Scale bars = 100 μm.

FIGURE 14 A – I. Photographs of dorsal and ventral shields. A – D Monatractides australicus (Cook, 1986): A—specimen from Double Barrel Creek, Qld (male, dorsal shield), B—specimen from Double Barrel Creek, Qld (female, dorsal shield), C - specimen from Swampy Plain River, NSW (female, dorsal shield), D—specimen from Big Crystal Crek, Qld (male, ventral shield); E – F, H Monatractides polypapillatus sp. nov.: E—specimen from Double Barrel Creek, Qld (male, dorsal shield), F—specimen from Big Crystal Creek, Qld (male, ventral shield), H—specimen from Double Barrel Creek, Qld (female, dorsal shield). G Monatractides ironicus sp. nov.: specimen from Gordon Creek (Qld) (male, dorsal shield). I Monatractides harveyi sp. nov.: specimen from Barramundie Creek (NT) (male, dorsal shield).