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 Author Pešić, Vladimir Author Smit, Harry Author Mary, Nathalie text Zootaxa 2018 2018-09-21 4483 2 331 348 journal article 29506 10.11646/zootaxa.4483.2.6 22cbdae5-d356-4c53-901b-ec5221de39de 1175-5326 1437784 238FFAA7-37AF-43A0-9DD5-1D5EE2C79891 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 ). 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. 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. 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. 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 FIGURE 4. Torrenticola mayottensis sp. nov. , female, Dembéni River, Mayotte: A = dorsal shield; B = ventral; C = palp, medial view. Scale bars = 100 µm. 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 .