Torrenticola (Torrenticola) soniae Pešić sp. nov.

Figs 1, 2, 5 A

Type material examined.

Holotype • ♂, dissected and slide mounted (RMNH), Portugal, Guarda, Seia, Rio Alva, Praia Fluvial de Sabugueiro (Fig. 5 D), river, 40.401°N, 7.64°W, 1021 m a.s.l., 24 Aug. 2023, leg. Ferreira, Benitez-Bosco & Padilha, sequenced (BOLD ID: BSNTN 961-23) . Paratypes: • 2 ♂ (sequenced), Portugal, Guarda, Seia, Rio Alva, Praia fluvial de Vila Cova a Coelheira, river, 40.379°N, 7.736°W, 312 m a.s.l., 23 Aug. 2023, leg. Ferreira, Benitez-Bosco & Padilha ; • 1 ♂ (sequenced); Manteigas, Zêzere, Ponte dos Frades, 40.403°N, 7.526°W, 672 m a.s.l., 22 Aug. 2023, leg. Ferreira, Benitez-Bosco, Padilha, Andrade & Stur ; • 1 ♀ (sequenced), dissected and slide mounted (RMNH), Guarda, Gouveia, Rio Mondego, Casais de Folgosinho, 40.454°N, 7.493°W, 976 m a.s.l., 24 Aug. 2023, leg. Ferreira, Benitez-Bosco & Padilha ; • 1 ♀ (juv.; sequenced), Bragança, Mirandela, Torre de Dona Chama, 41.665°N, 7.146°W, 256 m a.s.l., 13 Jul. 2023, leg. Ferreira & Padilha.

Diagnosis.

Morphological: Cx-I relatively short, anteriorly broad; suture lines of Cx-IV prominent, starting at right angle from genital field; ejaculatory complex with well-developed anterior keel and proximal arms; gnathosomal rostrum short, less than width of gnathosoma; P- 3 with a subrectangular, apically serrated ventrodistal projection. Molecular: this lineage represented by a unique BIN (BOLD: AFW 5337) differs from T. brevirostris clade by 12.27 % K 2 P for COI.

Description.

General features. Idiosoma roundish; dorsal shield without a color pattern as photographed in Figs 2 B, 5 A; area of primary sclerotization of the dorsal plate with two dorsoglandularia (Fig. 1 A); frontal platelets broad, relatively short; Cx-I relatively short, anteriorly broad; gnathosomal bay U-shaped, proximally rounded; Cxgl- 4 subapical; medial suture line of Cx-II + III relatively short; postgenital area extended; excretory pore and Vgl- 2 away from the line of primary sclerotization, excretory pore on the level of Vgl- 2; gnathosomal rostrum short, less than depth of gnathosoma (Fig. 1 E); P- 2 ventral margin nearly straight or slightly convex, P- 2 ventrodistal protrusion bluntly pointed, apically serrated, P- 3 with a subrectangular, apically serrated ventrodistal projection, P- 4 with a ventral tubercle bearing one long and three shorter setae (Fig. 1 C, D). Male. Suture line of Cx-IV evident, medially starting from posterior margin of genital field in a right angle to the main idiosoma axis; genital field large, subrectangular; ejaculatory complex conventional in shape, anterior keel, proximal and distal arms well developed (Fig. 1 F). Female. Genital field large and pentagonal in shape, suture lines of Cx-IV extending posteriorly beyond posterior margin of genital field, laterally curved.

Measurements.

Male (holotype). Idiosoma (ventral view: Fig. 1 B) L 912, W 669; dorsal shield (Fig. 1 A) L 756, W 581, L / W ratio 1.3; dorsal plate L 700; shoulder plate L 220–222, W 97, L / W ratio 2.27–2.29; frontal plate L 150–156, W 78–88, L / W ratio 1.8–1.9; shoulder / frontal plate L 1.42–1.47. Gnathosomal bay L 171, Cx-I total L 359, Cx-I mL 188, Cx-II + III mL 137; ratio Cx-I L / Cx-II + III mL 2.63; Cx-I mL / Cx-II + III mL 1.37. Genital field L / W 191 / 163, ratio 1.17; distance genital field-excretory pore 116, genital field-caudal idiosoma margin 209. Ejaculatory complex L 291.

Gnathosoma vL 331, chelicera L 375; palp total L 398, dL / H, dL / H ratio: P- 1, 39 / 39, 1.0; P- 2, 117 / 73, 1.59; P- 3, 84 / 63, 1.35; P- 4, 120 / 42, 2.86; P- 5, 38 / 17, 2.18; L ratio P- 2 / P- 4, 0.98. dL of I-L- 4–6: 134, 150, 136; I-L- 6 H 100; dL / H I-L- 6 ratio 1.36.

Female (paratype from Casais de Folgosinho, BGE_00227_F 02). Idiosoma (ventral view: Fig. 2 C) L 1033, W 828; dorsal shield (Fig. 2 A, B) L 844, W 725, L / W ratio 1.16; dorsal plate L 781; shoulder plate L 222–235, W 100–102, L / W ratio 2.2–2.3; frontal plate L 173–175, W 97–98, L / W ratio 1.79; shoulder / frontal plate L 1.28–1.34. Gnathosomal bay L 200, Cx-I total L 384, Cx-I mL 184, Cx-II + III mL 18; ratio Cx-I L / Cx-II + III mL 21.3; Cx-I mL / Cx-II + III mL 10.2. Genital field L / W 221 / 198, ratio 1.12; distance genital field-excretory pore 250, genital field-caudal idiosoma margin 391.

Gnathosoma vL 350, chelicera L 409; palp total L 435, dL / H, dL / H ratio: P- 1, 44 / 41, 1.08; P- 2, 127 / 76, 1.67; P- 3, 93 / 65, 1.44; P- 4, 134 / 42, 3.18; P- 5, 37 / 18, 2.0; L ratio P- 2 / P- 4, 0.94.

Etymology.

The species is dedicated to Sónia Ferreira (CIBIO, Portugal) for collecting numerous specimens used in this study and her enthusiastic support in the study of Portuguese water mites.

Species delimitation using DNA barcodes.

The final alignment for species delimitation using COI sequence data comprised 669 nucleotide positions (nps) of the 130 Torrenticola specimens listed in Suppl. material 2 and one outgroup, Monatractides madritensis from Portugal to root the tree. The NJ tree is presented in Fig. 6. The COI tree sequences retrieved from Torrenticola specimens from Portugal, here described as T. soniae sp. nov., appeared as a sister group to the cluster of sequences belonging to T. brevirostris (Halbert, 1911), a rhitrobiontic species widely distributed in Europe. The mean genetic distance between COI sequences of these two clusters was estimated at 12.27 ± 1.42 % K 2 P. The genetic distance was considerably higher than the estimated barcode gap found by ASAP analyses (3–5 %) of all studied Torrenticola, supporting the species-status of the new taxon. The mean intraspecific K 2 P - divergence within the cluster of the new species was 0.63 ± 0.19 %.

Discussion.

With regards to the presence of an anteriorly broad and short Cx-I, a robust and compact palp, and a deep gnathosoma with a short rostrum, the new species resembles T. brevirostris . The latter species can be separated from T. soniae sp. nov. by only slightly protruding ventrodistal projections of P- 2 and particularly of P- 3.

Distribution.

Portugal (this study).