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

Pešić, Vladimir & Smit, Harry, 2014, Torrenticolid water mites (Acari: Hydrachnidia: Torrenticolidae) from Ghana, Zootaxa 3820 (1), pp. 1-80 : 44-46

Monatractides melpomene n. sp.

( Figs. 28A–H , 37A–B , 38A–B , 44B )

Type series. Holotype male, dissected and slide mounted, Ghana: Amedzofe Falls, 6º 50.656 N, 0º 26.868 E, alt. 599 m asl., 20.ii.2013, Smit. Paratypes: 3 [one juvenile]/8 [two juveniles]/0, same data as holotype, 1/2/0 dissected and slide mounted; 0/1/0, unnamed creek upstream Sagyimase, Atewa Hills, 6º 13.966 N, 0º 33.114 W, alt. 671 m asl., 28.ii.2013, Smit, dissected and slide mounted.

Diagnosis. Dorsal shield with colour pattern as illustrated in Figs. 37A–B , ventral seta on P-3 comparatively stouter than seta on P-2, ventral setae on P-4 slender and short, not reaching the tip of P-5. Male: genital field with long setae at lateral and posterior margins, ejaculatory complex with small proximal chamber.

Description. General features —Idiosoma roundish; shoulder platelets elongated (shoulder/frontal platelets L ratio 1.5–1.7); dorsal shield with colour pattern as illustrated in Figs. 37A–B , frontal margin medially with large anterolaterally pointed apodemes ( Figs. 28C , 29B ); Cxgl–4 located far distal at tips of Cx-I; gnathosomal bay deep, narrow U-shaped, proximally pointed, three pairs of knob-like protrusions at the lateral margins of gnathosomal bay; posterior suture line of Cx-IV distinct, originating from lateral edge of genital field; excretory pore away from the line of primary sclerotization, Vgl-2 well posterior to excretory pore; gnathosoma compact, with long dorsal apodemes, rostrum truncated ( Fig. 28G ); palp ( Figs. 28D–E , 29C ): ventral seta on P-3 comparatively stouter than seta on P-2; distal margin of P-3 and P-4 medially and laterally with several pointed extensions; ventral setae on P- 4 slender and short, not reaching the tip of P-5. Male: medial margin of Cx-II/III relatively short; genital field oval, anteriorly enlarged and triangular, lateral margins slightly convex, slightly tapering to caudal end, genital flaps with long setae at lateral and posterior margins ( Fig. 28F ); ejaculatory complex with small proximal chamber ( Fig. 44B ). Female: genital field elongated trapezoid, anteriorly enlarged, laterally straight, tapering posteriorly.

Measurements. Male (holotype, in parentheses paratype from Amedzofe Falls, n = 1)—Idiosoma (ventral view: Figs. 28B , 38A ) L 734 (709), W 594 (583); dorsal shield ( Figs. 28A , 37A ) L 632 (600), W 519 (516), L/W ratio 1.22 (1.16); dorsal plate L 597 (560); shoulder platelets L 188–194 (181–188), W 63–67 (66–68), L/W ratio 2.9–3.0 (2.8); frontal platelets L 113–114 (116–117), W 61 (66–69), L/W ratio 1.84–1.86 (1.7–1.8), shoulder/ frontal platelets L ratio 1.64–1.72 (1.57–1.6). Gnathosomal bay L 147 (147), Cx-I total L 261 (277), Cx-I mL 114 (129), Cx-II+III mL 51 (41); ratio Cx-I L/Cx-II+III mL 5.1 (6.8); Cx-I mL/Cx-II+III mL 2.2 (3.1). Genital field L/ W 167 (166)/128 (129), ratio 1.31 (1.28); ejaculatory complex L (238); distance genital field-excretory pore 150 (141), genital field-caudal idiosoma margin 253 (223). Gnathosoma vL 157 (162); chelicera total L 208 (211); palp total L 225–228 (223–226), dL/H, dL/H ratio: P-1, 26/32, 0.81 (21–22/32, 0.67); P-2, 63–64/46, 1.37 (71/46, 1.54); P-3, 43/38–39, 1.12 (41–42/40, 1.04); P-4, 61–62/26, 2.35 (58–59/26, 2.23); P-5, 32/15, 2.1 (32/15, 2.1); P-2/P-4 ratio 1-03 (1.22); dL of I-L-2–6: 72 (71), 90 (85), 106 (104), 103 (99), 105 (105); I-L-6 H 38–39 (38–39), dL/H I- L-6 ratio 2.74 (2.72).

Female (paratype from Amedzofe Falls, n = 1)—Idiosoma (ventral view: Figs. 29A , 38B ) L 758, W 631; dorsal shield ( Fig. 37B ) L 619, W 531, L/W ratio 1.17; dorsal plate L 581; shoulder platelets L 183–188, W 66–67, L/W ratio 2.79; frontal platelets L 116–120, W 61, L/W ratio 1.9–2.0; shoulder/frontal platelets L ratio 1.5–1.6. Gnathosomal bay L 147, Cx-I total L 267, Cx-I mL 120, Cx-II+III mL 36; ratio Cx-I L/Cx-II+III mL 7.4; Cx-I mL/ Cx-II+III mL 3.3. Genital field L/W 178/162–163, ratio 1.1; distance genital field-excretory pore 156, genital fieldcaudal idiosoma margin 266. Gnathosoma vL 155; chelicera total L 217; palp total L 229, dL/H, dL/H ratio: P-1, 26/31, 0.84; P-2, 65/47, 1.38; P-3, 43/40, 1.08; P-4, 63/26–27, 2.38; P-5, 32/15, 2.14; P-2/P-4 ratio 1.03; dL of I-L- 2–6: 65, 86, 106, 105, 105; I-L-6 H 38–39, dL/H I-L-6 ratio 2.72.

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

Discussion. See discussion under Monatractides euterpe n. sp.

Habitat. Sandy/bouldary streams, shaded by rainforest.

Distribution. Ghana.

Figures

FIGURE 28 A – H. Monatractides melpomene n. sp., male, Amedzofe Falls: A = dorsal shield; B = idiosoma, ventral view; C = frontal margin of idiosoma, dorsal view; D = palp, medial view; E = palp, lateral view (P- 1 lacking); F = genital field; G = gnathosoma; H = I-L- 5 and - 6. 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.

FIGURE 44 A – L. Photographs of ejaculatory complex: A Monatractides convexiscutata (K. Viets, 1958), male, Asukuma River. B M. melpomene n. sp., Amedzofe Falls. C M. euterpe n. sp., creek upstream Sagyimase. D M. cf. ventriosus (K. Viets, 1916), male, Laboun River. E – L Monatractides microstoma - species complex (E – G—Form '' A' ', H – L—Form '' B' '; E – H—ejaculatory complex reduced to sclerotized framework above the genital field, I – L ejaculatory complex slide-mounted): E, L = specimens from Tagbo River, F, H – K = specimens from Apkonu stream, G = specimen from Plunge pool Agumatsa Falls.

FIGURE 29 A – C. Monatractides melpomene n. sp., female, Amedzofe Falls: A = dorsal shield; B = frontal margin of idiosoma, dorsal view; C = palp, medial view. Scale bars = 100 Μm.