Monatractides (Monatractides) ironicus, 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 : 15-17

Monatractides (Monatractides) ironicus sp. nov.

( Figs. 8–9 , 14G )

Type material. Holotype male, dissected and slide mounted, Queensland, Gordon Creek, Iron Range NP, 07.ix.2000 (QM). Paratypes: 3/2/0 (QM), 4/2/0 ( RMNH), same data as holotype, 2/2/0 dissected and slide mounted; East Claudie River, Iron Range NP, 08.ix.2000 7/6/0 ( RMNH).

Further records. Queensland: West Claudie River, Iron Range NP, 07.ix.2000 1/0/0; Middle Claudie River, Iron Range NP, 07.ix.2000 1/0/0; Cockatoo Creek, Cape York Peninsula, 11.ix.2000 2/0/0; unnamed creek 29 km E of Pascoo River at crossing with Iron Range NP road, Cape York Peninsula, 10.ix.2000 1/1/0.

Diagnosis. Frontal plate broad (L/W 1.5–2.0); area of primary sclerotization of the dorsal plate with four dorsoglandularia; capitular bay slender (L/W ratio 4.0–4.6); anterolateral edges of Cx-3 strongly protruding and pointed; posterior suture line of Cx-4 well accentuated, its medial margins approached to each other well posterior to the posterior margin of genital field; Vgl-2 slightly anterior to excretory pore and away from the line of primary sclerotization; distal margins of P-2 and -3 without denticles, ventral seta on P-4 slender and short; I-L-6 relatively stout (L/H ratio 2.4–2.6).

Description. Male (holotype, in parentheses paratypes, n = 2): Idiosoma (ventral view: Fig. 8B ) L 794 (756– 775), W 475 (447–466); dorsal shield ( Fig. 8A ) L 606 (581–594), W 414 (400–406), L/W ratio 1.46 (1.45–1.46); dorsal plate 550 (534–539); shoulder plate L 159–163 (153–170), W 61–62 (58–69), L/W ratio 2.61–2.63 (2.3– 2.74); frontal plate L 108–110 (92–99), W 59–62 (58–59), L/W ratio 1.74–1.86 (1.56–1.68); shoulder/frontal plate L ratio 1.47–1.48 (1.6–1.79); colour pattern as illustrated in Fig. 14G ; capitular bay L 171 (159–169), W 38 (37), L/W ratio 4.5 (4.57); Cx-1 total L 284 (272–278), Cx-1 medial L 113 (109–113), Cx-2+3 medial 81 (73–81); ratio Cx-1 L/Cx-2+3 medial L 3.5 (3.4–3.7); Cx-1 medial L/Cx-2+3 medial L 1.4 (1.35–1.55); genital field posteriorly narrowed, L/W 138 (133–138)/106 (100–106), L/W ratio 1.3 (1.3–1.33); ejaculatory complex ( Fig. 8E ) normal in shape, L 181 (180–188); distance genital field–excretory pore 219 (200–203), genital field–caudal idiosoma margin 287 (261–272); capitulum ( Fig. 9B ) ventral L 173 (158–165); chelicera total L 202 (182–187); palp ( Fig. 9A ): total L 161 (161), dL: P-1, 23 (23–24); P-2, 46 (47–48); P-3, 35 (34); P-4, 42 (42); P-5, 15 (14); P-2/P-4 ratio 1.1 (1.12–1.14); L I-4-6 ( Fig. 8C ): 73 (68–69), 80 (74–78), 82 (79–80); I-L-6 L/H 2.49 (2.45–2.5).

Female (paratypes, n = 2): Idiosoma (ventral view: Fig. 9 H) L 763–813, W 463–506; dorsal shield ( Fig. 9 G) L 581–628, W 400, L/W ratio 1.45–1.57; dorsal plate 537–578; shoulder plate L 147–163, W 50–65, L/W ratio 2.48– 3.1; frontal plate L 94–106, W 50–63, L/W ratio 1.68–2.0; shoulder/frontal plate L ratio 1.47–1.65; colour pattern as in male; capitular bay L 164–166, W 42, L/W ratio 4.0; Cx-1 total L 275–284, Cx-1 medial L 109–120, Cx-2+3 medial 60–67; ratio Cx-1 L/Cx-2+3 medial L 4.2–4.6; Cx-1 medial L/Cx-2+3 medial L 1.79–1.8; genital field pentgonal, L/W 144–150/125–129, L/W ratio 1.15–1.16; eggs (n = 3) maximum diameter L 169–178; distance genital field–excretory pore 225–234, genital field–caudal idiosoma margin 274–303; capitulum ventral L 164–175; chelicera total L 190–197; palp ( Fig. 9C ): total L 151–164, dL: P-1, 23–25; P-2, 45–48; P-3, 31–34; P-4, 39–43; P-5, 13–14; P-2/P-4 ratio 1.11–1.15; L I-4-6: 67–72, 71–76, 76–79; I-L-6 L/H 2.56–2.57.

Discussion. Due to the relatively broader frontal plates, a short medial suture line of Cx-2+ 3 in males, the absence of knob-shaped protrusions at the lateral margin of the capitular bay and extended postgenital area in both sexes, Monatractides ironicus sp. nov. most closely resembles M. australicus . In both sexes, M. ironicus sp. nov. can be distinguished by suture lines of Cx-4 medially approached to each other, well posterior to the posterior margin of the genital field (suture line of Cx-4 medially approached to each other close to the posterior margin of genital field in M. australicus ) and Vgl–2 located slightly anterior to, or on the level of, the excretory pore, away from the line of primary sclerotization (Vgl–2 well posterior to the excretory pore which lays in an identation of the line of primary sclerotization in M. australicus ). Further differences concern the more narrower capitular bay, a more slender male genital field, and the more elongated capitulum in M. ironicus sp. nov.

Etymology. Named after its occurence in Iron Range National Park; the name is a noun in apposition. Distribution. Australia: Queensland (present study).

Figures

FIGURE 8 A – H. Monatractides ironicus sp. nov., Gordon Creek (Qld) (A – E = male, F – H = female): A, G = dorsal shield; B, H = ventral shield; C = I-L- 5 - 6; D, F = anterodorsal portion of ventral shield; E = ejaculatory complex. Scale bars = 100 μm.

FIGURE 9 A – C. Monatractides ironicus sp. nov., Gordon Creek (Qld) (A – B = male, C = female): A = palp, medial view (P- 1 missing); B = capitulum; C = palp, lateral view. Scale bar = 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).