Monatractides K. Viets, 1926

Pešić, Vladimir & Smit, Harry, 2012, Second contribution to the knowledge of water mites of the genus Monatractides K. Viets (Acari: Hydrachnidia, Torrenticolidae) from New Guinea, with descriptions of three new species, Zootaxa 3350, pp. 46-57 : 47-50

Genus Monatractides K. Viets, 1926

Monatractides (Monatractides) alticolus Peši ć & Smit, 2011

New records. Indonesia, New Guinea, West Papua province: stream Ilik near Lake Gita, Anggi Lakes, 17.xi.2011, 1˚ 21.423 S, 133˚ 58.553 E, alt. 1912 m asl, 2/0/0 (1/0/0 mounted); stream ca. 3 km S of Mokwam, 08.xi.2011, 1˚ 05.877 S, 133˚ 54.223 E, alt. 1637 m asl, 3/0/0 (1/0/0 mounted).

Distribution. New Guinea: Papua province ( Pešiċ & Smit 2011); West Papua province (present study).

Monatractides (Monatractides) humilis Peši ć & Smit, 2011

New records. Indonesia, New Guinea: West Papua province: river at Warkapi, S of Manokwari, 13.xi.2100, 1˚ 0 9.978 S, 134˚ 0 7.028 E, alt. 101 m asl, 1/0/0; river Ngamung, 15.xi.2011, 1˚ 14.466 S, 133˚ 52.538 E, alt. 1833 m asl, 1/1/0 (1/0/0 mounted). Papua province: river Yabawi, upstream of Harapan, 30.x.2011, 2˚ 34.216 S, 140˚ 33.723 E, alt. 120 m asl, 6/7/0; unnamed creek N of Sentani, 30.x.2011, 2˚ 32.734 S, 140˚ 29.270 E, alt. 177 m asl, 3/1/3 (1/0/0 mounted); unnamed creek N of Sentani (after flash flood), 31.x.2011, 2˚ 32.734 S, 140˚ 29.271 E, alt. 177 m asl, 7/2/3.

Distribution. New Guinea: Papua province ( Pešiċ & Smit 2011; present study); West Papua province (present study).

Monatractides (Monatractides) cf. nipsanicus Peši ć & Smit, 2011 ( Figs. 1A–E , 2 )

New records. Indonesia, New Guinea, West Papua province: river Ngamung, 15.xi.2011, 1˚ 14.466 S, 133˚ 52.538 E, alt. 1833 m asl, 4/3/0 (2/1/0 mounted); river Asiti, W of Senopi, 22.xi.2011, 0˚ 51.469 S, 132˚ 54.957 E, alt. 502 m asl, 1/0/0.

Morphology. Male (from river Ngamung, n = 2): Idiosoma: (ventral view: Fig. 1B ) L 869–897, W 572–578; dorsal shield ( Fig. 1A ) L 731–763, W 469–481, L/W ratio 1.56–1.59; dorsal plate 705–719; shoulder plate L 200–209, W 66–78, L/W ratio 2.7–3.0; frontal plate L 150–164, W 56–67, L/W ratio 2.4–2.7; shoulder/frontal plate L ratio 1.27–1.35; capitular bay L 166–194, W 81–84, L/W ratio 2.1–2.3; Cx-1 total L 298–334, Cx-1 medial L 131–141, Cx-2+3 medial L 67; ratio Cx-1 L/Cx-2+3 medial L 4.4–5.0; Cx-1 medial L/Cx-2+3 medial L 2.0–2.1; genital field L/W 181–192/123–134, L/W ratio 1.43–1.47, ejaculatory complex L 213–217; distance genital field–excretory pore 180–194, genital field–caudal idiosoma margin 292–306; capitulum ( Fig. 1D ) ventral L 220–239; chelicera total L 277–288; palp ( Fig. 1C ) total L 267–275, dL: P-1, 37; P-2, 73–79; P-3, 52–54; P-4, 72–76; P-5, 31; L P-2/P-4 ratio, 1.01–1.04; L I-4–6 ( Fig. 1E ): 119–151, 129–163, 132–157; I-L-6 L/H ratio, 3.0–3.1.

Female (from river Ngamung, n = 1): Idiosoma: (ventral view: Fig. 2 ) L 828, W 625; dorsal shield L 791, W 516, L/W ratio 1.53; dorsal plate 750; shoulder plate L 209–214, W 66–75, L/W ratio 2.9–3.2; frontal plate L 153–155, W 63–68, L/W ratio 2.3–2.4; shoulder/frontal plate L ratio 1.37–1.38; capitular bay L 188, W 80, L/W ratio 2.35; Cx-1 total L 322, Cx-1 medial L 134, Cx-2+3 medial L 37; ratio Cx-1 L/Cx-2+3 medial L 8.7; Cx-1 medial L/Cx-2+3 medial L 3.6; genital field L/W 195/153, L/W ratio 1.28; distance genital field–excretory pore 184, genital field–caudal idiosoma margin 363; capitulum ventral L 229; chelicera total L 283; palp total L 257, dL: P-1, 33; P-2, 71; P-3, 54; P-4, 71; P-5, 28; L P-2/P-4 ratio, 1.0; L I-4–6: 138, 147, 147; I-L-6 L/H ratio, 3.1.

Remarks. In view of the similar shape of the idiosoma (e.g. idiosoma and genital field elongated, dorsal shield L/W> 1.5, genital field L/W ratio> 1.4, excretory pore on the line of primary sclerotization) and palps, these specimens show a general conformity with Monatractides nipsanicus Pešiċ & Smit 2011 , a species known only from a single male specimen from the Nipsan district in Papua province ( Pešiċ & Smit 2011). Differences are found in the major idiosoma and gnathosoma dimensions and the considerably elongated genital field (L/W ratio 1.6) in the holotype of M. nipsanicus . Study of more material of the latter species from the locus typicus is necessary before a decision can be made whether specimens from West Papua represent an undescribed ‘western’ sister species of M. nipsanicus or our data enlarge the known variability of the latter.

Monatractides (Monatractides) sentanicus Peši ć & Smit, 2011 ( Fig. 3A–C )

New records. Indonesia, New Guinea, Papua province, unnamed creek N of Sentani (after flash flood), 31.x.2011, 2˚ 32.734 S, 140˚ 29.271 E, alt. 177 m asl, 0/1/0 (mounted).

Morphology. Female. Idiosoma (ventral view: Fig. 3B ) L 675, W 419; dorsal shield ( Fig. 3A ) L 578, W 353, L/W ratio 1.64; dorsal plate 545; shoulder plate L 175, W 56, L/W ratio 3.1; frontal plate L 100–103, W 47–48, L/ W ratio 2.1–2.2; shoulder/frontal plate L ratio 1.75; capitular bay L 152, W 73, L/W ratio 2.1; Cx-1 total L 259, Cx-1 medial L 106, Cx-2+3 medial L 24; ratio Cx-1 L/Cx-2+3 medial L 10.8; Cx-1 medial L/Cx-2+3 medial L 4.4; genital field L/W 144/128, L/W ratio 1.13; distance genital field–excretory pore 150, genital field–caudal idiosoma margin 245; capitulum ventral L 179; chelicera L 247; palp ( Fig. 3C ) total L 207, dL: P-1, 27; P-2, 60; P-3, 39; P- 4, 57; P-5, 24; L P-2/P-4 ratio, 1.05; L I-L-4–6: 82, 95, 103; I-L-6 L/H ratio, 2.7.

Remarks. The specimen from the unnamed creek N of Sentani agrees well with the description of M. sentanicus , a species so far only known from a single female specimen from Papua Province (River Pos 7, Sentani, Pešiċ & Smit 2011).

Distribution. New Guinea: Papua province ( Pešiċ & Smit 2011; present study).

Figures

FIGURE 2. Monatractides cf. nipsanicus Pešić & Smit 2011, female, river Ngamung: ventral shield. Scale bar = 100 μm.

FIGURES 1 A – E. Monatractides cf. nipsanicus Pešić & Smit 2011, male, river Ngamung: A = dorsal shield; B = ventral shield; C = palp, medial view; D = capitulum and chelicera; E = I-L- 5 and - 6. Scale bars = 100 μm.

FIGURES 3 A – C. Monatractides sentanicus Pešić & Smit 2011, female, unnamed creek N of Sentani: A = dorsal shield; B = ventral shield; C = palp, medial view. Scale bars = 100 μm.