Atractides (Atractides) putihi Wiles, 1991

Pesic, Vladimir & Smit, Harry, 2009, New records of water mites of the genus Atractides Koch, 1837 (Acari: Hydrachnidia, Hygrobatidae) from Thailand, Malaysia and Sulawesi (Indonesia), with the description of four new species, Zootaxa 2240, pp. 1-30 : 25-26

Atractides (Atractides) putihi Wiles, 1991

( Figs. 18A–D , 19A–C )

Material. THAILAND: unnamed creek crossing track from watchtower, Khao Yai NP 11.xi.2007, 14° 27.533 N 101° 20.386 E, leg. Smit, 1/0/0 (1/0/0 mounted); stream near Haewsai Waterfall, Nam Nao NP, alt. 425 m, 16.xi.2007, 16° 40.668 N 101° 41.856 E, leg. Smit, 0/1/0 (0/1/0 mounted); slow flowing stream, Nam Nao NP, alt. 1190 m, 15.xi.2007, 15° 14.442 N 101° 34.774 E, leg. Smit, 0/1/0.

Morphology. General features. Integument dorsally striated. Muscle attachment plates unsclerotized. Coxal field with the medioposterior margin of Cx-1+2 sharply curved, lateral and posterior margins of Cx- 3+4 with extended secondary sclerotization, distinctly projecting posteriorly to lateral margins. Excretory pore smooth; Vgl-1 separated from Vgl-2. Palp with a weak sexual dimorphism, P-4 with a strong sword seta, inserting proximally from proximoventral hair; I-Leg: setae S-1 and S-2 similar in length, close to each other; IV-Leg-5 ( Fig. 19C ) with two swimming setae at distal and nearly long as IV-Leg-6.

Male (from unnamed creek crossing track from watchtower, Thailand): Idiosoma L/W 431/309. Coxal field ( Fig. 18A ): L 234, Cx-1+2 mL 112, Cx-3 W 242, Cx-1+2 lL 178. Palp ( Fig. 18C ): total L 195, dL and %L (in parentheses): P-1 18 (9.2), P-2 49 (25.1), P-3 34 (17.4), P-4 68 (34.9), P-5 26 (13.3); L P-2/P-4 0.72. Genital field ( Fig. 18B ): with nearly straight or slightly convex anterior margin, L/W 65/86, L Ac-1-3: 21-21- 27.

I-Leg ( Fig. 18D ): I-Leg-5 dL 94, vL 73, dL/vL 1.29, HB 33, dL/HB 2.9, S-1 L 46, L/ W 6.8, S-2 L 46, L/ W 6.1, distance of sword setae at I-Leg-5 6, L S-1/2 1.0; I-Leg-6 L 57, HB 11, L/HB 5.0; L I-Leg-5/6 1.65.

Female (from stream near Haewsai Waterfall, Thailand): Idiosoma L/W 480/359. Coxal field ( Fig. 19A ): L 221, Cx-3 W 245, Cx-1+2 mL 85, Cx-1+2 lL 156. Palp: total L 210, dL and %L (in parentheses): P-1 21 (10.0), P-2 52 (24.8), P-3 36 (17.1), P-4 70 (33.3), P-5 31 (14.8); L P-2/P-4 0.74; capitulum ventral L 84. Genital field ( Fig. 19A ): gonopore long, genital plates in a right angle, restricted to the level of the postgen, Ac in triangular position, L/W 111/113, genital plate L 52, L Ac-1-3: 22-21-21; egg diameter (n=2) 97-100.

I-Leg ( Fig. 19B ): I-Leg-5 dL 92, vL 77, dL/vL 1.2, HB 32, dL/HB 2.9, S-1 L 45, L/ W 7.3, S-2 L 44, L/ W 6.0, distance of sword setae at I-Leg-5 5.0, L S-1/2 1.02; I-Leg-6 L 59, HB 11, L/HB 5.2; L I-Leg-5/6 1.56.

Remarks. In the original description Wiles (1991) mentioned the similarity with Atractides diversus Cook and A. minutus Walter , two polyacetabulate members of the subgenus Polymegapus , known from India. Atractides putihi resemble the species of the later subgenus in the shape of the palp (sword seta on P-4 fingerlike, inserting proximal to proximoventral hair), but differs in the following features (in parentheses diagnostic features of the subgenus Polymegapus , from Gerecke 2003): I-Leg-5 with ventral margin shorter than dorsal margin (the ventrodistal edge of I-Leg-5 extends clearly over the dorsodistal one), S-1 not extremely inflated (S-1 strongly enlarged in the proximal part, distally narrowed to a rather fine trip) and idiosoma with unsclerotized muscle attachment plates (idiosoma with strong sclerification due to sclerotized muscle attachments). Its possible that Atractides putihi within Atractides s.str. represents an intermediate species on the bridge to Polymagapus. To address this interesting question, additional studies on larval morphology and the application of molecular genetics techniques are necessery. Only the female of this species is known ( Wiles 1991), and this is the first description of the male. According to Wiles (1991) several specimens of this species, including a male, have been collected from Sulawesi.

Distribution. Malaysia ( Wiles 1991). New for Thailand.

Figures

FIGURE 18 A – D. Atractides putihi Wiles, 1991, male, from unnamed creek crossing track from watchtower, Thailand: A = coxal and genital field; B = genital field; C = palp, medial view; D = I-Leg- 5 and - 6. Scale bars = 100 μm.

FIGURE 19 A – C. Atractides putihi Wiles, 1991, female, stream near Haewsai Waterfall, Thailand: A = idiosoma, ventral view; B = I-Leg- 5 and - 6; C = IV-Leg- 5 and - 6. Scale bars = 100 μm.