Monatractides terpsichore, Pešić, Vladimir & Smit, Harry, 2014

Pešić, Vladimir & Smit, Harry, 2014, Torrenticolid water mites (Acari: Hydrachnidia: Torrenticolidae) from Ghana, Zootaxa 3820 (1), pp. 1-80 : 51-54

Monatractides terpsichore n. sp.

( Figs. 34A–G , 35A–B , 37H , 38H )

Type series. Holotype female, dissected and slide mounted, Ghana, Plunge pool Agumatsa Falls, Agumatsa Wildlife Sanctuary, 7º 06.350 N, 0º 36.476 E, alt. 258 m asl., 22.ii.2013 Smit. Paratypes: one male, Nubui River, Agumatsa Wildlife Sanctuary, 7º 06.986 N, 0º 35.548 E, alt. 254 m asl., 22.ii.2013, Smit, dissected and slide mounted.

Diagnosis. P-2 longer than P-4, P-2 with long and slender ventral seta located away from distal edge, P-4 bowed, ventral margin with setae-bearing protrusion in the centre of the segment.

Description. General features —Idiosoma roundish; frontal platelets slightly shorter than shoulder platelets (shoulder/frontal platelets L ratio 1.05–1.07); frontal margin medially pointed, between anterolaterally orientated apodemes ( Fig. 34A ); Cxgl-4 located far anteriorly, near tip of Cx-I; gnathosomal bay deep U-shaped, proximally wide box-shaped; posterior suture line of Cx-IV strongly extending posteriorly beyond posterior margin of genital field, laterally curved; excretory pore and Vgl-2 away from the line of primary sclerotization, Vgl-2 posterior to excretory pore; gnathosoma nearly triangular in lateral view, with short, cone-shaped rostrum ( Fig. 34G ); P-2 longer than P-4, P-2 ventral margin straight or slightly concave, bearing long and slender ventral seta located away from distal edge, P-3 ventral margin concave, P-4 bowed, ventral margin with setae-bearing protrusion in the centre of the segment ( Figs. 34D–E , 35B ). Male: medial margin of Cx-II/III relatively short; genital field subrectangular. Female: genital field pentagonal.

Measurements. Female (holotype)—Idiosoma (ventral view: Figs. 34C , 38H ) L 697, W 567; dorsal shield ( Figs. 34B , 37H ) L 588, W 478, L/W ratio 1.22; dorsal plate L 538; shoulder platelets L 141–144, W 64–69, L/W ratio 2.04–2.25; frontal platetelets L 131–134, W 71–72, L/W ratio 1.8–1.9; shoulder/frontal platelets L ratio 1.07. Gnathosomal bay L 147, Cx-I total L 256, Cx-I mL 109, Cx-II+III mL 27; ratio Cx-I L/Cx-II+III mL 9.6; Cx-I mL/ Cx-II+III mL 4.1. Genital field L/W 152/144, ratio 1.06; distance genital field-excretory pore 172, genital fieldcaudal idiosoma margin 261. Gnathosoma vL 167; chelicera total L 183–184, basal segment L 143–151, claw L 36–39, L basal segment/claw ratio 3.7–4.1; palp total L 203–204, dL/H, dL/H ratio: P-1, 28/24, 1.16; P-2, 63/ 41–42, 1.52; P-3, 40/33–34, 1.19; P-4, 51/23, 2.2; P-5, 21–22/11, 1.9; P-2/P-4 ratio 1.24; dL of I-L-2-6: 68, 74, 92, 99, 103; I-L-6 H 41–42, dL/H I-L-6 ratio 2.5.

Male (paratype from Nubui river)—Idiosoma (ventral view: Fig. 35A ) L 589, W 456; dorsal shield L 494, W 406, L/W ratio 1.22; dorsal plate L 453; shoulder platelets L 128, W 61, L/W ratio 2.1; frontal platelets L 122, W 58–59, L/W ratio 2.0–2.1; shoulder/frontal platelets L ratio 1.05. Gnathosomal bay L 136, Cx-I total L 237, Cx-I mL 100, Cx-II+III mL 37.5; ratio Cx-I L/Cx-II+III mL 6.3; Cx-I mL/Cx-II+III mL 2.7. Genital field L/W 122/103, ratio 1.18; distance genital field-excretory pore 133, genital field-caudal idiosoma margin 192. Gnathosoma vL 147; chelicera total L 168; palp total L 182–183, dL/H, dL/H ratio: P-1, 25/22, 1.1; P-2, 55/42, 1.32; P-3, 35/32, 1.09; P-4, 46/21–22, 2.15; P-5, 21–22/11, 2.0; P-2/P-4 ratio 1.2; dL of I-L-2–6: 60, 68, 86, 92, 95–96; I-L-6 H 39–42, dL/H I-L-6 ratio 2.3–2.45.

Etymology. The species is named after Terpsichore (Ancient Greek: Τερψιχόρη), one of nine Muses from Greek mythology, who was a patron of dance. The species name is a noun in apposition (in the nominative case).

Discussion. The combination of a relatively short and bowed P-4 and the ventral seta on P-2 clearly shifted from the distal edge, separates the new species from other members of the genus. Due to the latter character, Monatractides (M.) terpsichore n. sp. somehow resembles M. (M.) divergens ( Cook, 1966) ( Liberia, Cook 1966), and M. (M.) amota ( K.O. Viets, 1974) ( Congo, K.O. Viets & Böttger 1974), both characterized by the ventral seta on P-2 and P-3, respectively, shifted from the distal edge of the segment. The latter species is similar in the general shape of gnathosoma and chelicera (vs. gnathosoma with apically pointed, rostrum and chelicerae with a larger claw in M. (M.) divergens , see Cook 1966) but can easily be distinguished by the relatively longer and slender P-4, without ventral tubercle (see K.O. Viets & Böttger 1974).

Remarks. The male ejaculatory complex was not found but sclerotized framework immediately above the genital field can be hardly visible.

Habitat. Plunge pool and a sandy/bouldary streams, shaded by forest.

Distribution. Ghana.

Figures

FIGURE 34 A – G. Monatractides terpsichore n. sp., female, Plunge pool, Agumatsa Falls: A = frontal margin of idiosoma, dorsal view; B = dorsal shield; C = idiosoma, ventral view; D = palp, medial view; E = palp, lateral view; F = I-L- 4 – 6; G = gnathosoma and chelicera. Scale bars = 100 Μm.

FIGURE 35 A – B. Monatractides terpsichore n. sp., male, Nubui River: A = idiosoma, ventral view; B = palp, lateral view (inset P- 2 ventral margin, medial view). Scale bars = 100 Μm.

FIGURE 37 A – I. Photographs of dorsal shield. A – B Monatractides melpomene n. sp., Amedzofe Falls: A = male holotype, B = female paratype. C – D M. euterpe n. sp., creek upstream Sagyimase: C = male holotype, D = female paratype. E – F M. polyhymnia n. sp., Kue River: E = male holotype, F = female paratype. G M. thalia n. sp., male holotype, Agumatsa River. H M. terpsichore n. sp., female holotype, Plunge pool. I M. urania n. sp., male paratype, Kintampo Falls.

FIGURE 38 A – I. Photographs of ventral shield. A – B Monatractides melpomene n. sp., Amedzofe Falls: A = male holotype, B = female paratype. C – D M. euterpe n. sp., creek upstream Sagyimase: C = male holotype, D = female paratype. E – F M. polyhymnia n. sp., Kue River: E = male holotype, F = female paratype. G M. thalia n. sp., male holotype, Agumatsa River. H M. terpsichore n. sp., female holotype, Plunge pool. I M. urania n. sp., male paratype, Kintampo Falls.