Torrenticola bomiensis Cook, 1966

Pešić, Vladimir & Smit, Harry, 2014, Torrenticolid water mites (Acari: Hydrachnidia: Torrenticolidae) from Ghana, Zootaxa 3820 (1), pp. 1-80 : 5-10

Torrenticola bomiensis Cook, 1966

( Figs. 3A–D , 4A–B , 12C–D , 14C–D )

Torrenticola bomiensis Cook 1966: 65 .

New records. Ghana: Tagbo River, downstream of falls, 7º 00.708 N, 0º 34.326 E, alt. 394 m asl., 23.ii.2013, Smit, 0/1/0 (mounted); Supon stream near Asiakwa, Atewa Hills, 6º 15.530 N, 0º 30.642 W, 7.iii.2011, Smit, 2[one juvenile]/1/0 (1/0/0 mounted).

Morphology. General features —Idiosoma roundish; Cxgl–4 subapical, only slightly posterior of Cx-I tips (not described in the original description); suture of Cx-IV extending beyond posterior margin of genital field; excretory pore and Vgl–2 slightly posterior the line of primary sclerotization, excretory pore slightly posterior to Vgl–2 ( Fig. 3B ); ventral margin of gnathosoma rather straight, rostrum not clearly set off from gnathosomal base ( Fig. 3D ); P-2 ventral margin straight, distally with a subrectangular, anteriorly directed and apically serrated projection and a very short, denticle-like seta laterally at base of projection; P-3 with a subrectangular, laterally directed and apically serrated ventrodistal projection and a long seta laterally at base of projection; P-4 stocky, with well developed ventral protuberance bearing one long and 1–3 short setae ( Figs. 3C , 4B ). Male: genital field subrectangular in shape; ejaculatory complex normal in shape. Female: genital field pentagonal in shape.

Measurements. Male (from Supon stream, n = 1)—Idiosoma (ventral view: Figs. 4A , 14C ) L 563, W 403; dorsal shield ( Fig. 12C ) L 458, W 334, L/W ratio 1.37; dorsal plate L 424; shoulder platelets L 130–134, W 48, L/ W ratio 2.7–2.8; frontal platelets L 122–125, W 50–52, L/W ratio 2.42–2.44; shoulder/frontal platelets L ratio 1.04–1.1. Gnathosomal bay L 87–88, Cx-I total L 219, Cx-I mL 131, Cx-II+III mL 94; ratio Cx-I L/Cx-II+III mL 2.3; Cx-I mL/Cx-II+III mL 1.4. Genital field L/W 122/100, ratio 1.22; ejaculatory complex L 174; distance genital field-excretory pore 91, genital field-caudal idiosoma margin 125. Gnathosoma vL 255; chelicera total L 289; palp total L, dL/H, dL/H ratio: P-1, 25/25, 1.0; P-2, 75/40, 1.88; P-3, 58/37, 1.56; P-4, 75/23, 3.2; P-5, 16/12, 1.3; P-2/P- 4 ratio 1.01; dL of I-L-2–6: 48, 54, 69, 74, 72; I-L-6 H 29, dL/H I-L-6 ratio 2.5.

Female (from Tagbo River, n = 1)—Idiosoma (ventral view: Figs. 3B , 14B ) L 650, W 428; dorsal shield ( Figs. 3A , 12D ) L 516, W 373, L/W ratio 1.38; dorsal plate L 481; shoulder platelets L 147, W 50–52, L/W ratio 2.8–2.9; frontal platelets L 134, W 53–55, L/W ratio 2.4–2.5; shoulder/frontal platelets L ratio 1.1. Gnathosomal bay L 100, Cx-I total L 248, Cx-I mL 148, Cx-II+III mL 75; ratio Cx-I L/Cx-II+III mL 3.3; Cx-I mL/Cx-II+III mL 2.0. Genital field L/W 133/125, ratio 1.06; distance genital field-excretory pore 137, genital field-caudal idiosoma margin 194. Gnathosoma vL 291; chelicera total L 325; palp total L, dL/H, dL/H ratio: P-1, 29/28, 1.04; P-2, 88/48, 1.85; P-3, 65/44, 1.48; P-4, 82/25, 3.3; P-5, 19/12, 1.6; P-2/P-4 ratio 1.08; dL of I-L-2-6: 53, 60, 79, 85, 85; I-L-6 H 32, dL/H I-L-6 ratio 2.6.

Remarks. The specimens from Ghana in their general morphology agree well with Torrenticola bomiensis Cook, 1966 , a species widely distributed and numerous in Liberia ( Cook 1966). Differences with the original description (in parentheses, from Cook 1966) are found in slightly larger dimensions, the suture of Cx-IV extending further beyond the posterior margin of the genital field and the excretory pore shifted slightly posterior to Vgl-2 (lying on the same level as Vgl-2). In the figure of the palp of T. bomiensis given by Cook (1966) the ventral seta on P-2 is missing completely. Furthermore, the subapical position of Cxgl-4 can be speculated only on the basis of Cook’s figure ( Cook 1966, Fig. 169) of the ventral shield and the presence of a seta, with a minute dot, lying on the outer edge of Cx-I. Thus, our attribution of T. bomiensis is still provisional, and additional material is necessary to clarify its taxonomy.

Distribution. Liberia ( Cook 1966); Ghana (first record).

Figures

FIGURE 3 A – D. Torrenticola bomiensis Cook, 1966, female, Tagbo River: A = dorsal shield; B = idiosoma, ventral view; C = palp, medial view; D = gnathosoma. Scale bars = 100 Μm.

FIGURE 4 A – B. Torrenticola bomiensis Cook, 1966, male, Supon stream: A = idiosoma, ventral view; B = palp, medial view. Scale bars = 100 Μm.

FIGURE 12 A – I. Photographs of dorsal shield: A – B Torrenticola anomallela Cook, 1966: A = male from Akaa Falls, B = female from Apkonu stream. C – D Torrenticola bomiensis Cook, 1966: C = male from Supon stream, D = female from Tagbo river. E – F Torrenticola fasciata (K. Viets, 1916), unnamed creek crossing road to Ankasa NP: E—male, F—female. G – H Torrenticola motasi Cook, 1966: G = female from tributary of Oguntwe, H = male from stream downstream of Wanjakli Falls. I Neoatractides erato n. sp., holotype male, upstream Sagyimase.

FIGURE 14 A – I. Photographs of ventral shield: A – B Torrenticola anomallela Cook, 1966: A = male from Akaa Falls, B = female from Apkonu stream. C – D Torrenticola bomiensis Cook, 1966: C = male from Supon stream, D = female from Tagbo river. E – F Torrenticola fasciata (K. Viets, 1916), unnamed creek crossing road to Ankasa NP: E = male, F = female. G – H Torrenticola motasi Cook, 1966: G = male from stream downstream of Wanjakli River, H = female from tributary of Oguntwe. I Neoatractides erato n. sp., holotype male, upstream Sagyimase.