Monatractides

Pešić, Vladimir & Smit, Harry, 2014, Torrenticolid water mites (Acari: Hydrachnidia: Torrenticolidae) from Ghana, Zootaxa 3820 (1), pp. 1-80 : 70-71

Monatractides sp. 1

( Figs. 47A–E , 49A–B )

Material examined. Ghana: Apkonu stream, downstream of falls, 6º 53.054 N, 0º 28.024 E, alt. 362 m asl., 21.ii.2013, Smit, 1/0/0 (mounted).

Morphology. Male. General features —Idiosoma elongated-oval; dorsal shield elongated with frontal platelets much shorter than shoulder platelets ( Figs. 47A , 49A ); frontal margin medially convexly rounded, between large anterolaterally pointed protrusions ( Fig. 47C ); Cxgl–4 located far anteriorly, near tips of Cx-I; gnathosomal bay Ushaped and moderately deep; medial margin of Cx-II/III relatively short; genital field small and roundish; suture line of Cx-IV strongly extending posteriorly beyond posterior margin of genital field, laterally curved, medially closer together ( Figs. 47B , 49B ); excretory pore slightly away from the line of primary sclerotization, excretory pore anterior to Vgl–2; palp: ventral seta on P-4 short ( Fig. 47D ).

Measurements. Idiosoma (ventral view: Figs. 47B , 49B ) L 656, W 425; dorsal shield ( Figs. 47A , 49A ) L 548, W 366, L/W ratio 1.5; dorsal plate L 500; shoulder platelets L 161–163, W 59–63, L/W ratio 2.6–2.7; frontal platelets L 111–114, W 59–63, L/W ratio 1.8–1.9; shoulder/frontal platelets L ratio 1.43–1.45. Gnathosomal bay L 125, Cx-I total L 247, Cx-I mL 122, Cx-II+III mL 68; ratio Cx-I L/Cx-II+III mL 3.6; Cx-I mL/Cx-II+III mL 1.8. Genital field L/W 108/102–103, ratio 1.05; distance genital field-excretory pore 167, genital field-caudal idiosoma margin 231. Gnathosoma vL 149; chelicera total L 164; palp total L 142, dL/H, dL/H ratio: P-1, 21–22/18, 1.19; P- 2, 40/28, 1.44; P-3, 29/24, 1.23; P-4, 37/17, 2.18; P-5, 15/9, 1.7; P-2/P-4 ratio 1.08; dL of I-L-2–6: 53, 71, 92, 100, 101–102; I-L-6 H 40, dL/H I-L-6 ratio 2.54.

Discussion. Due to the relatively small and more roundish genital field and suture line of Cx-IV strongly extending back beyond genital field ( Fig. 47B ), the single male from Apkonu stream resembles Monatractides dolichosoma , a species known from several sites in Liberia ( Cook 1966). The latter species is notably smaller and can easily be distinguished by a very slender idiosoma (L/W ratio 1.8, data calculated from Cook 1966). It is very likely that the specimen from Apkonu stream represent a taxon new for science. However, a final decision can be given only when larger series are available.

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

Figures

FIGURE 47 A – E. Monatractides sp. 1, male, Apkonu stream: A = dorsal shield; B = idiosoma, ventral view; C = frontal margin of idiosoma, dorsal view; D = palp, medial view; E = I-L- 5 and - 6. Scale bars = 100 Μm.

FIGURE 49 A – E. Photographs of: A – B Monatractides sp. 1, male, Apkonu stream: A = dorsal shield; B = idiosoma, ventral view. C – E Monatractides sp. 2, male, Kintampo Falls: C = dorsal shield; D = idiosoma, ventral view; E = inner side of genital field (arrow showing ejaculatory complex reduced to sclerotized framework).