Neoatractides sundaensis, Pešić & Smit, 2014

Pešić, Vladimir & Smit, Harry, 2014, Torrenticolid water mites (Acari: Hydrachnidia: Torrenticolidae) from Malaysian Borneo, Zootaxa 3840 (1), pp. 1-72 : 28-32

Neoatractides sundaensis n. sp.

( Figs. 19A–F , 22A–B )

Type series. Holotype female, dissected and slide mounted, Malaysia, Borneo , stream Kemantis , Sayap, Mt Kinabalu, 6º09.841 N, 116º33.936 E, alt. 928 m asl., 16.ix.2012 Smit.

Diagnosis (Male unknown). Shoulder platelets fused to the large dorsal plate; P-1 separate from P-2, P-2 and - 3 without ventral projections, P-2 with relatively long and slender seta in distal half of segment, dorsal margin proximally convexly protruding; P-3 with relatively long, hair-like ventral seta inserted in the proximal half of the segment; gnathosoma with long and slender rostrum, without conspicuous oral papillae

Description

Female. General features —Shoulder platelets fused to the large dorsal plate ( Figs. 19B , 22A ); gnathosomal bay shallow; tips of Cx-I truncated; Cxgl-4 far posterior at margin of Cx-I/II, halfway between I-L and II-L insertions; genital field pentagonal in shape; suture line of Cx-IV distinct, extending posteriorly beyond posterior margin of genital field; excretory pore away from the line of primary sclerotization, Vgl-2 posterior from excretory pore; P-1 separate from P-2, P-2 and -3 without ventral projections, P-2 relatively long, ventral margin concave, with relatively long and slender seta inserted in distal half of the segment, dorsal margin proximally convexly protruding, ventral margin of P-3 slightly concave, with relatively long, hair-like seta inserted in proximal half of the segment ( Fig. 19E ); gnathosoma with short posterodorsal projections, lacking conspicuous oral papillae, rostrum long and slender ( Fig. 19C ); chelicera long with relatively short cheliceral claw (L basal segment/claw ratio 6.7). Legs: I-L ( Fig. 19F ) with I-L-6 L/H ratio 2.8.

Measurements —Idiosoma (ventral view: Figs. 19A , 22B ) L 684, W 503; dorsal shield ( Figs. 19B , 22A ) L 596, W 447, L/W ratio 1.33; dorsal plate L 563; frontal plate L 139, W 44, L/W ratio 3.18. Gnathosomal bay L 63, Cx-I total L 245, Cx-I mL 182, Cx-II+III mL 47; ratio Cx-I L/Cx-II+III mL 5.2; Cx-I mL/Cx-II+III mL 3.9. Genital field L/W 152/133, ratio 1.14; distance genital field-excretory pore 153, genital field-caudal idiosoma margin 242. Gnathosoma vL 378; chelicera total L 406, basal segment L 377, claw L 56, L basal segment/claw ratio 6.7; palp total L 258, dL/H, dL/H ratio: P-1, 30/52, 0.57; P-2, 107/49-54, 2.0–2.2; P-3, 75/37, 2.04; P-4, 31/26, 1.19; P-5, 15/ 18.5, 0.79; P-2/P-4 ratio 3.43. Legs: dL of I-L-5–6: 88, 89; I-L-6 H 32, dL/H I-L-6 ratio 2.76.

Male: unknown.

Etymology. Named after Sunda Shelf; major landmasses on the shelf include the Malay Peninsula, Sumatra, Borneo, Java, Madura, Bali and their surrounding smaller islands.

Discussion. The subgenus Allotorrenticola includes six species from Asia, i.e., Neoatractides abnormipalpis ( Lundblad, 1941) ( Burma, Malaysia, Brunei; Wiles 1997), N. bahtilli ( Wiles, 1991) ( Malaysia, Thailand; Wiles 1997, Pešić & Smit 2009a), N. malayensis ( Wiles, 1991) ( Malaysia, Thailand; Wiles 1997, Pešić & Smit 2009a), N. suvarna ( Cook, 1967) ( India, Cook 1967), N. farmerae Wiles, 1999 (Borneo, Wiles 1999) and N. calidus Pešić & Smit, 2012 (South Iran, Pešić et al. 2012a), and N. erato Pešić & Smit, 2014 (West Africa, Pešić & Smit 2014).

The shape of dorsal shield with the shoulder platelets fused to the large dorsal plate, makes the new species most similar to Neoatractides erato , a species recently described from Ghana ( Pešić & Smit 2014). The latter species can easily be distinguished by the series of different character states: gnathosoma with conspicuous oral papillae (sensu Wiles 1997), P-2 maximum height at distal margin, P-3 stout with short ventral seta located in the distal half, P-4 almost equal in length with P-3, cheliceral claw relatively long, gnathosomal bay moderately deep (see Pešić & Smit 2014).

Two Allotorrenticola species previously reported from Borneo ( Wiles 1999), N. abnormipalpis and N. farmerae can easily be distinguished from N. sundaensis n. sp. in addition to the shoulder platelets not fused to the large dorsal plate, by P-1 partially fused with P-2 (see Wiles 1999).

Habitat. Sandy/bouldery streams, shaded by rain forest ( Fig. 43D ).

Distribution. Borneo; known only from the locus typicus.

Subgenus Heteratractides Lundblad, 1941

Figures

FIGURE 19A–F. Neoatractides sundaensis n. sp., female holotype, Kemantis stream: A = idiosoma, ventral view; B = dorsal shield; C = gnathosoma and chelicera; D = palp, lateral view; E = palp, medial view, F = I-L-5 and -6. Scale bars = 100 µm.

FIGURE 22A–F. Photographs of dorsal (A,C,E) and ventral shield (B,D,F). A–B Neoatractides sundaensis n. sp., female holotype, Kemantis stream. C–D Neoatractides uniscutatus n. sp., male holotype, Kemantis stream. E–F Pseudotorrenticola borneoensis n. sp., male holotype, Little Lumotok stream.

FIGURE 43A–D. Photographs of selected sampling sites: A—Mahua stream (type locality of Torrenticola kinabaluensis n. sp. and sampling site of Torrenticola borneoensis n. sp., T. sabahensis n. sp., T. minuta, T. neoindica n. sp., T. cf. pugionirostris, Monatractides longiventris, M. parviventris and M. morpheus n. sp.), B—Unnamed stream Bansadon Trail (type locality of Neoatractides uniscutatus n. sp. and sampling site of Torrenticola borneoensis n. sp., T. kinabaluensis n. sp., Monatractides cf. macroporus and M. parviventris). C—Kibamabangan River (type locality of Torrenticola schilthuizeni n. sp. and sampling site of Torrenticola borneoensis n. sp., T. kinabaluensis n. sp., T. minuta and T. neoindica n. sp., Monatractides cf. macroporus, M. oxystomus, M. parviventris and M. morpheus n. sp.). D—Kemantis stream (type locality of Torrenticola borneoensis n. sp., Neoatractides sundaensis n. sp. and Monatractides phantasos n. sp. and sampling site of T. minuta, Monatractides longiventris, M. parviventris and M. morpheus n. sp.). Photos. H. Smit.