Torrenticola mayottensis Pešić & Smit, 2018

Pešić, Vladimir, Smit, Harry & Mary, Nathalie, 2018, Fifth contribution to the knowledge of water mites (Acari: Hydrachnidia) from the Comoros: a checklist and description of one new genus and four new species, Zootaxa 4483 (2), pp. 331-348 : 334-338

Torrenticola mayottensis Pešić & Smit n. sp.

( Figs. 3–4 , 11C–D )

Synonymy. Torrenticola sp. Smit et al. (2010, p. 52, figs. 2A–D).

Type series. Holotype male ( MNHN), dissected and slide mounted, Comoros, Mayotte, Dembéni River, downstream, 12°51'38,7"S, 43°09'30,8"E, alt. 10 m asl., 31-vii-2014, leg. Mary. Paratypes ( MNHN): same site and data as holotype, 1/0/0; same site, 18-vii-2015 4[3 juvenile]/6[2 juvenile]/0 (0/2/0 dissected and slide mounted) ( RMNH).

Other material. Comoros, Mayotte: River Bouyouni, intermediate, 12°44'55,6"S, 45°08'36,4"E, alt. 40 m asl., 5-viii-2014 0/1/0 (mounted); Mapouhera upstream, 12°43'4,3"S, 45°05'56,6"E, alt. 110 m asl., 24-vii-2015 0/1/0; River Banano, upstream, 12°54'1,2"S, 45°11'9, 8"E, alt. 50 m asl., 21-vii-2015 3[2 juvenile]/0/0 (1/0/0 mounted); River Dapani, upstream, 12°57'42,4"S, 45°09'22,7"E, alt. 37 m asl., 20-vii-2015 0/1[juvenile]/0; River Djalimou, upstream, 12°56'58,4"S, 45°07'23,7"E, alt. 165 m asl., 16-vii-2015 0/1/0; River Djalimou, downstream, 12°57'14,0"S, 45°06'53,2"E, alt. 30 m asl., 30-vii-2015 1/0/0.

Diagnosis. Both sexes: Idiosoma elongated-oval (dorsal shield L/W ratio 1.3–1.4); gnathosomal rostrum long; P-4 stout, L/H 2.4–3.0; female: genital field roundish, L/W 0.95–1.05.

Description. General features —Idiosoma elongated-oval; gnathosomal bay U-shaped, proximally rounded; Cxgl-4 subapical, only slightly posterior to Cx-I tips; suture line of Cx-IV distinct, extending posteriorly beyond posterior margin of genital field; excretory pore in a medioposterior indentation of primary sclerotization, Vgl-2 posterior to excretory pore; gnathosomal rostrum long, ventral margin strongly curved ( Fig. 3E ); P-2 ventral margin slightly curved, ventrodistal protrusion slender, spatula-shaped, distally finely serrate; ventrodistal projection at P-3 irregularly cone-shaped, anterior margin frayed; P-4 relatively short, dorsal margin weakly curved, with ventral tubercles pointed and separated, bearing one long and three short setae ( Figs. 3F–G ). Male: medial suture line of Cx-II+III short; genital field subrectangular in shape; posterior suture lines of Cx-IV starting at right angle from genital field ( Fig. 3C ); ejaculatory complex apically long, cella proximalis small ( Fig. 3D ). Female: genital field roundish in shape

Measurements. Male (holotype; in parentheses specimen from River Banano, n = 1)—Idiosoma (ventral view: Fig. 3C ) L 650 (691), W 414 (450); dorsal shield ( Figs. 3A , 11C ) L 515 (534), W 363 (394), L/W ratio 1.4 (1.36); dorsal plate L 491 (511); shoulder plate L 159 (156–159), W 53 (53), L/W ratio 3.0 (2.8–2.9); frontal plate L 116– 118 (114–116), W 42–44 (44), L/W ratio 2.6–2.8 (2.6); shoulder/frontal plate L 1.35–1.38 (1.35–1.4). Gnathosomal bay L 169 (173), Cx-I total L 292 (314), Cx-I mL 125 (141), Cx-II+III mL 78 (84); ratio Cx-I L/Cx-II+III mL 2.3 (2.2); Cx-I mL/Cx-II+III mL 3.7 (3.7). Genital field L/W 138 (141)/119 (124), ratio 1.16 (1.13); ejaculatory complex L 200 (222); distance genital field-excretory pore 89 (92), genital field-caudal idiosoma margin 141 (149). Gnathosoma vL 291 (325), chelicera L 345 (381); palp total L 274 (275), dL/H, dL/H ratio: P-1, 30/31, 0.95 (30/27, 1.1); P-2, 92/44, 2.1 (98/50, 2.0); P-3, 58/40, 1.45 (58/42, 1.37); P-4, 75/25, 3.0 (72/28, 2.6); P-5, 19/13, 1.5 (17/12, 1.5); P-2/P-4 ratio 1.23 (1.37). dL of I-L: 50, 56, 66, 83 (88), 95 (100), 86 (87); I-L-6 H 33 (33); dL/H I-L- 6 ratio 2.6 (2.6).

Female (paratype, n = 2; in parentheses specimen from River Bouyouni, n = 1)—Idiosoma (ventral view: Fig. 4B ) L 716–744 (740), W 497–519 (516); dorsal shield ( Figs. 4A , 11D ) L 572–575 (563), W 406–431 (422), L/W ratio 1.33–1.41 (1.33); dorsal plate L 541–550 (541); shoulder plate L 169–172 (159), W 56–59 (59), L/W ratio 2.8–3.0 (2.7); frontal plate L 119–131 (120–122), W 47–50 (49–50), L/W ratio 2.4–2.8 (2.4–2.5); shoulder/frontal plate L 1.29–1.42 (1.31–1.33). Gnathosomal bay L 186–195 (184), Cx-I total L 325–341 (325), Cx-I mL 140–145 (141), Cx-II+III mL 27–28 (34); ratio Cx-I L/Cx-I mL 2.3 (2.3); Cx-I mL/Cx-II+III mL 12.6 (9.6). Genital field L/ W 142–150 (147)/144–150 (141), ratio 0.95–1.04 (1.05); distance genital field-excretory pore 122–162 (138), genital field-caudal idiosoma margin 213–231 (231). Gnathosoma vL 331–344 (331); chelicera total L 413–419 (397); palp total L 302–311 (282), dL/H, dL/H ratio: P-1, 36–40/36–39, 1.0–1.12 (31/31, 1.0); P-2, 108/50–52, 2.09–2.16 (100/47, 2.13); P-3, 63–64/42–45, 1.42–1.48 (63/43, 1.44); P-4, 78–81/27–28, 2.8–3.0 (71/29, 2.45); P- 5, 17–18/14–16, 1.15–1.22 (17/14, 1.25); P-2/P-4 ratio 1.33–1.38 (1.41). dL of I-L: 52, 61, 69, 89 (92), 100 (100), 84 (80); I-L-6 H 34 (31); dL/H I-L-6 ratio 2.45 (2.6).

Etymology. Named for its occurrence on Mayotte.

Remarks. Smit et al. (2010) reported a single female of Torrenticola from Dembéni River. Later on, the same authors assigned this specimen to T. comorosensis Pešić & Smit, 2015 described originally on the basis of a male and female from a tributary of Koualé River (Pešić et al. 2015a).

Additional material of this study reveals that females from Dembéni River fit perfectly the description of the unnamed specimen described by Smit et al. (2010), but they have to be assigned to the new species T. mayottensis sp. nov. This new species differs from T. comorosensis (data taken from Pešić et al. 2015a) in a number of morphological features: 1) dorsal shield with a colour pattern (without colour in T. comorosensis , compare Figs. 11C–D with Figs. 4A, D in Pešić et al. 2015a), 2) gnathosomal rostrum comparatively longer (compare Fig. 3E with Fig. 2D in Pešić et al. 2015a), and 3) P-4 stouter in the both sexes, L/H 2.4–3.0 (3.6–3.7 in T. comorosensis ). The female of the new species can be separated from T. comorosensis on the basis of more roundish genital field, L/ W 0.95–1.05 vs. more elongated in T. comorosensis , L/W ratio 1.12 (compare Fig. 4B with Fig. 3C in Pešić et al. 2015).

Distribution. Comoros: Mayotte.

Figures

FIGURE 2. Platymamersopsis mayottensis sp. nov., male, Koualé River, Mayotte: A = dorsal shield; B = ventral; C = IV-L-5 and -6; D = I-L; E = palp. Scale bars = 100 µm.

FIGURE 3. Torrenticola mayottensis sp. nov., male, Dembéni River, Mayotte: A = frontal margin of idiosoma, dorsal view; B = dorsal shield; C = ventral; D = ejaculatory complex; E = gnathosoma; F = palp, lateral view; G = palp, medial view (P-1 lacking). Scale bars = 100 µm.

FIGURE 4. Torrenticola mayottensis sp. nov., female, Dembéni River, Mayotte: A = dorsal shield; B = ventral; C = palp, medial view. Scale bars = 100 µm.

FIGURES 11. Photographs of dorsal (A, C–E) and ventral (B, F): A–B Platymamersopsis mayottensis sp. nov., male holotype. C–D Torrenticola mayottensis sp. nov.: C = male holotype, F = female paratype. E–F Djeboa davecooki sp. nov., male holotype.