Monatractides koenikei ( K. Viets, 1916 )

Pešić, Vladimir & Smit, Harry, 2014, Torrenticolid water mites (Acari: Hydrachnidia: Torrenticolidae) from Ghana, Zootaxa 3820 (1), pp. 1-80 : 32-34

Monatractides koenikei ( K. Viets, 1916)

( Figs. 20A–F , 21A–B , 25D–E , 26D–E )

Atractides koenikei K. Viets 1916: 265 .

New records. Ghana: Akaa Falls, 6º 10.516 N, 0º 11.723 W, 9.iii.2011, alt. 180 m asl., Smit, 0/1/0 (mounted); Nubui River, Agumatsa Wildlife Sanctuary, 7º 06.986 N, 0º 35.548 E, alt. 254 m asl., 22.ii.2013, Smit, 1/0/0 (mounted).

Morphology. General features —Idiosoma roundish; shoulder platelet elongated (shoulder/frontal platelets L ratio 1.4); Cxgl–4 located far anteriorly, near tips of Cx-I; gnathosomal bay moderately deep, narrow U-shaped, apically widened, three pairs of knob-like protrusions at lateral margins of gnathosomal bay; posterior suture line of Cx-IV nearly obliterated, originating from lateral edge of genital field; excretory pore and Vgl-2 away from the line of primary sclerotization, excretory pore slightly posterior to Vgl-2; gnathosoma elongated with long dorsal apodemes ( Fig. 20F ); palp segments short and compact; P-2 longer than P-4; P-4 rather stout with a strong dorsomedial peg-like seta, located away from the distal edge,ventral seta on P-4 slender and nearly reaching tip of P-5 ( Figs. 20C–D ). Male: medial margin of Cx-II/III relatively long; genital field subrectangular; ejaculatory complex with small proximal chamber, carina anterior long ( Fig. 21B ). Female: genital field pentagonal.

Measurements. Male (from Nubui River, n = 1)—Idiosoma (ventral view: Figs. 21A , 26D ) L 603, W 506; dorsal shield ( Fig. 25D ) L 501, W 440, L/W ratio 1.14; dorsal plate L 463; shoulder platelets L 166, W 66, L/W ratio 2.5; frontal platelets L 122, W 64–66, L/W ratio 1.8–1.9; shoulder/frontal platelets L ratio 1.36. Gnathosomal bay L 93, Cx-I total L 209, Cx-I mL 116, Cx-II+III mL 109; ratio Cx-I L/Cx-II+III mL 1.9; Cx-I mL/Cx-II+III mL 1.1. Genital field L/W 112–113/98, ratio 1.15; ejaculatory complex L 161; distance genital field-excretory pore 133, genital field-caudal idiosoma margin 169. Gnathosoma vL 127; chelicera total L 172; palp total L 148, dL/H, dL/H ratio: P-1, 23/24, 0.95; P-2, 42/35, 1.21; P-3, 27/29, 0.93; P-4, 36/21 [maximum height 24], 1.74 [1.5]; P-5, 20/11–12, 1.7; P-2/P-4 ratio 1.17; dL of I-L-2–6: 52, 66, 85, 83, 95; I-L-6 H 33, dL/H I-L-6 ratio 2.9.

Female (from Akaa Falls, n = 1)—Idiosoma (ventral view: Figs. 20B , 26E ) L 627, W 534; dorsal shield ( Figs. 20A , 25E ) L 534, W 477, L/W ratio 1.12; dorsal plate L 491; shoulder platelets L 169–178, W 66–69, L/W ratio 2.6; frontal platelets L 123–127, W 63–64, L/W ratio 2.0; shoulder/frontal platelets L ratio 1.37–1.41. Gnathosomal bay L 86, Cx-I total L 205, Cx-I mL 119, Cx-II+III mL 84; ratio Cx-I L/Cx-II+III mL 2.4; Cx-I mL/Cx-II+III mL 1.4. Genital field L/W 137–138/137, ratio 1.01; distance genital field-excretory pore 150, genital field-caudal idiosoma margin 197. Gnathosoma vL 129; chelicera total L 169; palp: dL/H, dL/H ratio: P-2, 40/32, 1.26; P-3, 26/ 27, 0.96; P-4, 34/20, 1.7; P-5, 20/11–12, 1.7; P-2/P-4 ratio 1.19; dL of I-L-4–6: 88, 87, 93; I-L-6 H 33, dL/H I-L-6 ratio 2.8.

Remarks. The specimens from this study match the general morphology of Monatractides koenikei ( K. Viets, 1916) , a species originally described from Cameroon ( K. Viets 1958), and later on reported by Cook (1966) from Liberia.

Distribution. West Africa: Cameroon ( K. Viets 1916, 1925), Liberia ( Cook 1966), Ghana (new record).

Figures

FIGURE 20 A – F. Monatractides koenikei (K. Viets, 1916), female, Akaa Falls: A = dorsal shield; B = idiosoma, ventral view; C = palp, medial view (P- 1 lacking); D = palp, lateral view (P- 1 lacking); E = I-L- 4 and - 5; F = gnathosoma. Scale bars = 100 Μm.

FIGURE 21 A – B. Monatractides koenikei (K. Viets, 1916), male, Nubui River: A = idiosoma, ventral view; B = ejaculatory complex. Scale bars = 100 Μm.

FIGURE 25 A – I. Photographs of dorsal shield. A Monatractides acutiscutatus (K. Viets, 1914), female, unnamed creek upstream Sagyimase. B – C M. convexiscutata (K. Viets, 1958), stream Asukuma: B = male, C = female. D – E M. koenikei (K. Viets, 1916): D = male from Nubui River, E = female from Akaa Falls. F – G M. stigeophora (Cook, 1966), female: F = specimen from Supon stream, G = juvenile specimen from stream upstream Sagyimase. H – I M. cf. ventriosus (K. Viets, 1916): H = male from Laboun River, I = female from Agumatsa River.

FIGURE 26 A – I. Photographs of ventral shield. A Monatractides acutiscutatus (K. Viets, 1914), female, unnamed creek upstream Sagyimase. B – C M. convexiscutata (K. Viets, 1958), stream Asukuma: B = male, C = female. D – E M. koenikei (K. Viets, 1916): D = male from Nubui River, E = female from Akaa Falls. F – G M. stigeophora (Cook, 1966), female: F = specimen from Supon stream, G = juvenile specimen from stream upstream Sagyimase. H – I M. cf. ventriosus (K. Viets, 1916): H = male from Laboun River, I = female from Agumatsa River.