Hydrodroma golestanica, Pešić & Zawal & Saboori & Smit, 2021

Pešić, Vladimir, Zawal, Andrzej, Saboori, Alireza & Smit, Harry, 2021, New records of water mites (Acari, Hydrachnidia) from Iran with the description of one new species based on morphology and DNA barcodes, Zootaxa 5082 (5), pp. 425-440 : 427-430

Hydrodroma golestanica sp. nov.

Figs. 1-2

Material examined— Holotype ♂ ( RMNH), Iran, Golestan Province, IR3 Shirabad near Khanbebin , stream, downstream near bridge, 36.967499 N, 55.027779 E, 27.viii.2017 leg. Pešić, Zawal & Saboori, dissected and slidemounted . Paratypes: 2♂, 1♀, same place and data as holotype ( RMNH) ; 1♂ sequenced [ CCDB38361 F03] ; 1♀ dissected and slide-mounted ( RMNH) .

Diagnosis— Integument papillae rounded. Genital plates with 40–51 pairs of Ac in at most four longitudinal rows. Numbers of leg swimming setae: II-L-posterior 1; III-L-4 posterior 6-7; III-L-5 posterior 5; IV-L-4 anterior 6-8, posterior 6-7; IV-L-5 anterior 2-3, posterior 4-5.

Description. Both sexes: Integument papillae rounded ( Fig. 1C ). Cx-I+II medially separated by a fine membranous line, with a row of long fine setae at medial margins of Cx-I, and posterior margins of Cx-I, Cx-II, -III, and –IV. Genital flaps with rounded lateral and concave medial margins ( Figs. 1 A-B). Excretory pore sclerotized. Leg claws with a dorsal clawlet.

Male (holotype; in parentheses some measurements of the paratype specimen [CCDB 38361 F03]): Idiosoma L 1130, W 1090. Coxal field L 527; Cx-III W 559, L Cx-I+II 266, Cx-III+IV 278; coxal setae numbers: Cx-I, 24 (23); Cx-II, 23 (22); Cx-III, 14 (18); Cx-IV 11 (19). Genital plate ( Fig. 1A ) L 259 (238), on each plate Ac number 49-51 (49), with 36-40 setae, all hollow. Ejaculatory complex L 198.

Gnathosoma vL 228; chelicera ( Fig. 2D ) total L 297, L basal segment 238, claw 63, L ratio basal segment/claw 3.8. Palp ( Figs. 2 A-B) total L 444, dL/H, dL/H ratio: P-1, 55/45, 1.23; P-2, 73/56, 1.3; P-3, 50/53, 0.94; P-4, 186/47, 4.0; P-5, 80/22, 3.6; L ratio P-2/P-4, 0.4. dL IV-L: 128, 150, 200, 309, 313, 291.

Female (paratype, n = 1; juvenile specimen ([CCDB 38361 F05]): Idiosoma L 790. Coxal field L 486; Cx-III W 494, L Cx-I+II 256, Cx-III+IV 281; coxal setae numbers: Cx-I, 18; Cx-II, 18; Cx-III, 13; Cx-IV 12. Genital plate large, L 210-217, on each plate Ac number 40-42, with 30 setae.

Gnathosoma vL 228; chelicera total L 297, L basal segment 233, claw 63, L ratio basal segment/claw 3.7. Palp total L 446, dL/H, dL/H ratio: P-1, 53/45, 1.19; P-2, 77/57, 1.34; P-3, 52/55, 0.94; P-4, 189/42, 4.5; P-5, 75/22, 3.4; L ratio P-2/P-4, 0.41. dL IV-L: 125, 150, 205, 309, 328, 272.

Species delimitation using DNA-barcodes — The final alignment for species delimitation using COI sequence data of ten Hydrodroma specimens listed in Table 2 and one outgroup, Protzia cabardinica (BOLD: 8. IR8 2017 H2) from Iran to root the tree. The NJ tree is presented in Fig. 3 . The COI tree sequence retrieved from a specimen of H. golestanica sp. nov. from Iran appeared as a sister taxa of H. torrenticola ( Fig. 3 ). The average K2P genetic distance between the COI sequence of one specimen of H. golestanica sp. nov. from Iran and a specimen of H. torrenticola of from Montenegro was estimated to 10.1% ( Table 3 ).

Etymology— Named after the province where the new species was collected.

Discussion —The new species from Golestan Province closely resembles Hydrodroma torrenticola , a species widely distributed in the Palaearctic ( Di Sabatino et al. 2010). It shares the presence of only one short swimming seta on II-L-5 and 2-3 swimming setae on anterior IV-L-5. Only one specimen of the new species could be acquired for use in molecular analyses, so intraspecific differences in COI sequence could not be examined. The phylogenetic analysis based on COI data reveals that the new species is most similar to H. torrenticola . Level of COI differentiation between the new species from Iran and H. torrenticola from Montenegro was 10.1% K2P divergence.

From a morphological point of view, H. torrenticola can be separated from the new species by the shape of the integument papillae (pointed vs. distally rounded in H. golestanica sp. nov.).

Distribution— Iran.

Figures

FIGURE 1. Hydrodroma golestanica sp. nov. (A, C holotype ♂, B, ♀ paratype): A-B = genital field; C = integument papillae; D = photograph of dorsal integument in tangential view. Scale bars = 100 μm.

FIGURE 2. Hydrodroma golestanica sp. nov., holotype ♂: A = palp, lateral view; B = palp, medial view (P-1 missing); C = gnathosoma; D = chelicera; E = IV-L-5 and -6, posterior view. Scale bars = 100 μm..

FIGURE 3. Neighbor-joining tree based on studied Hydrodroma COI sequences. The optimal tree with the sum of branch length = 0.54910533 is shown. The analysis involved 11 nucleotide sequences. There were a total of 669 positions in the final dataset.