Monatractides roseus (Lundblad, 1941)

Pesic, Vladimir & Smit, Harry, 2010, New records of water mites (Acari: Hydrachnidia) from Malaysia, with descriptions of three new species, Zootaxa 2354, pp. 19-34 : 29-30

Monatractides roseus (Lundblad, 1941)

( Fig. 8A–E )

Material. Malaysia, Jerian stream, Fraser’s Hill, 3° 43.479 N 101° 42.935 E, alt. 1011 m, 14.ii.2009, 0/1/0 (mounted).

Morphology. Female: Idiosoma (ventral view: Fig. 8B ) L 781, W 641; dorsal shield ( Fig. 8A ) L 719, W 541, L/W ratio 1.33; dorsal plate 650; frontal plate L 153, W 78, L/W ratio 2.0; shoulder plate L 216, W 84, L/ W ratio 2.6; gnathosomal bay L 182, Cx-1 total L 321, Cx-1 medial L 139, Cx-2+3 medial 39; ratio Cx-1 L/ Cx-2+3 medial L 8.2; Cx-1 medial L/Cx-2+3 medial L 3.6; genital field L/W 192/167, L/W ratio 1.15; distance genital field–excretory pore 186, genital field–caudal idiosoma margin 229; capitulum ventral ( Fig. 8D ) L 218; chelicera L 262; palp ( Fig. 8C ) total L 211, dL and %L (in parentheses): P-1, 33 (15.6); P-2, 61 (28.9); P-3, 42 (19.9); P-4, 52 (24.6); P-5, 23 (10.9); L P-2/P-4 ratio, 1.17; P-4 lacking denticles near insertions of ventral setae; L I-Leg-4-6 ( Fig. 8E ): 103, 102, 101.

Remarks. This species belongs to the M. luteus ( K. Viets, 1935) species-complex, characterized by the presence of anteriorly broad and shorter Cx-1, a relatively wide capitular bay, a relatively short medial suture line of Cx-2+ 3 in both sexes and I-Leg-6 not greatly expanded. There are five similar species in this complex known from Java, Indonesia: Monatractides luteus ( K. Viets, 1935) , M. landbergi (Lundblad, 1941) , M. parvus (Lundblad, 1941) , M. roseus (Lundblad, 1941) and M. longiusculus (Lundblad, 1941) . Due to the combination of the larger dimensions of idiosoma and gnathosoma (vs. minor dimensions in M. parvus – see: Lundblad 1956, 1969, 1971), the dorsal shield less elongated (vs. elongated in M. longiusculus and M. parvu – see: Lundblad 1956, 1971) and having broad frontal platelets (vs. slender in M. luteus and M. longisculus – see: Viets 1935, Lundblad 1956, 1971), and Cx-4 strongly extended posterior to the genital flaps in the both sexes (vs. less extended in M. luteus , M. parvus and M. landbergi – see: Viets 1935, Lundblad 1956, 1971) the specimen from Malaysia resembles M. roseus . However, due to the fact that we do not have male specimens, this is only a tentative assignment. The variability of further specimens needs to be examined to clarify the taxonomy.

Distribution. Indonesia (Java). New for Malaysia.

Figures

FIGURE 8 A – E. Monatractides roseus (Lundblad, 1941), female: A = dorsal shield; B = ventral shield; C = palp, lateral view; D = capitulum and chelicera; E = I-Leg- 5 – 6. Scale Bars = 100 μm.