Sperchon (Sperchon) krameri, Pešić & Smit, 2022

Pešić, Vladimir & Smit, Harry, 2022, Two new water mite species from Kyrgyzstan (Acari, Acariformes, Hydrachnidia), Ecologica Montenegrina 58, pp. 69-78 : 70-74

Sperchon (Sperchon) krameri sp. nov.

https://zoobank.org/ urn:lsid:zoobank.org:act:D058AFDE-DA60-49A0-B1C9-AC30DC076ECB

Figs. 1-3 , 4 B-C

Type material — Holotype ♀, Kyrgyzstan, KR7 Chon-Kemin NP, stream near Ashu resort, Kalman Ashu village, 42º42.906' N, 076º04.767' E, 1542 m asl., 10.viii.2013, leg. Pešić & Smit, dissected and slide mounted ( RMNH) . Paratypes: 1♂, Kyrgyzstan, KR8 Chon-Kemin NP, upper part of stream near Ashu resort, Kalman Ashu village, 42º42.276' N, 76º05.101' E, 1644 m asl., 10.viii.2013, leg. Pešić & Smit, dissected and slide mounted ( RMNH) .

Diagnosis — Integument rugose; postocularia plate equal or slightly larger than glandularia platelets; Cx-III with a glandularium; P-2 with a long distoventral projection, near base of projection, with a stout seta which is equal or just slightly longer than the projection; sexual dimorphism on P-3 ventral margin (distinctly convex in female, slightly convex in male), P-4 long and slender, L/H ratio 7.5-8.1, ventral peg-like setae small, subdividing the ventral margin into three unequal parts, proximal part shorter than medial and distal ones; excretory pore sclerotized; III/IV-L with a few plumose dorsal setae.

Description General features — Integument dorsally and ventrally rugose, with flat papillae as showed in Fig. 1 (inset); muscle attachment plates unsclerotized, all glandularia on extended platelets ( Fig. 1 ). Coxal field: Cx-I+II medially close to each other, but not fused; Cx-III with a glandular opening (Cxgl-4) near anterior margin. Genital field: Ac-1-2 longish, Ac-3 more roundish ( Figs. 2A , 3C ). Excretory pore on a sclerotized ring similar in size to neighbouring glandularia ( Fig. 3A ).

Gnathosoma with the rostrum shorter than gnathosomal base ( Fig. 3E ). Palp: P-2 with long distoventral projection ( Figs. 2C , 3D ), its tip bearing two fine setae, near base of projection there is stout seta which is slightly shorter than the projection; ventral margin of P-3 nearly straight; P-4 longer than P-3, with two ventral tubercles, bearing small peg-like setae, proximal tubercle slightly larger than distal one, area between peg-like setae subdivides the ventral margin into three unequal parts, proximal part longer than medial and distal ones ( Fig. 2C ).

Leg segments slender, III/IV-L with a few plumose dorsal setae ( Fig. 2B ), ambulacrum with claw blade well protruding, bearing a long dorsal and a shorter ventral clawlet.

Measurements. Female (Holotype) — Idiosoma L 1690; postocularia plate 103 in diameter; distance between anterior end of Cx-I and posterior end of Cx-IV, 747; Cx-III W 981, L Cx-I+II, 325, Cx-III+IV, 438. Genital field (including pregenital sclerite) L/W 303/197, genital valves L 253, pregenital sclerite W 81; L Ac-1-3: 83, 95-98, 67.

Palp total 980, dL/H, dL/H ratio: P-1, 59/73, 0.8; P-2, 193/153, 1.26; P-3, 281/130, 2.17; P-4, 381/47, 8.1; P-5, 66/19, 3.5; L ratio P-2/P-4 0.5. Gnathosoma L 269; chelicera L 348, basal segment 266, claw L 86, L ratio cheliceral basal segment/claw 3.1. Leg segments dL: I-L: 113, 131, 194, 297, 319, 275; IV-L: 197, 238, 250, 506, 456, 394.

Male (paratype, n = 1) — Idiosoma L 1375; postocularia plate 97 in diameter; distance between anterior end of Cx-I and posterior end of Cx-IV, 600; Cx-III W 794; L Cx-I+II, 275, Cx-III+IV, 388. Genital field L/W 250/181, genital valves L 231; L Ac-1-3: 72, 78-81, 59-63. Ejaculatory complex ( Fig. 3B ) L 363.

Palp total 789, dL/H, dL/H ratio: P-1, 50/53, 0.94; P-2, 156/122, 1.28; P-3, 224/97, 2.3; P-4, 306/41, 7.5; P-5, 53/17, 3.1; L ratio P-2/P-4 0.5. Gnathosoma L 206; chelicera L 303, basal segment L231, claw L 75, L ratio chelicerae basal segment/claw 4.0. Leg segments dL: I-L: 88, 116, 159, 245, 266, 242; IV-L: 164, 194, 194, 400, 369, 316.

Etymology — Named after the Swedish acarologist C.J. Neuman (1839-1912), who erected the genus Sperchon .

Discussion — Sperchon krameri . sp. nov. is most similar to S. grigorievka Pešić & Smit, 2020 , known from Kyrgyzstan ( Pešić & Smit 2020). Both species have a rugose integument, without sclerotized muscle attachment plates, Cx-III with a glandularium, a rostrum shorter than the gnathosomal base, P-2 with a long ventrodistal projection, excretory pore surrounded by a sclerotized ring similar in size to neighbouring glandularia and IV-L-3-5 with a row of scattered plumose dorsal setae. Sperchon grigorievka which has been found to co-occur with the new species can be separated by more extended plates with the postocularia, a nearly straight ventral margin of P- 3 in the both sexes, and P-4 comparatively shorter (and consequently less slender, L/H ratio 4.4-4.9 in ♀, 3.2 in ♂; data from Pešić & Smit 2020) with disctinctly larger ventral- peg like setae (particularly the posteroventral one) which subdivides the ventral margin into three equal parts (compare Figs. 4A and -B ).

Sperchon glandulosus Koenike, 1886 , a species widely distributed in Central and Northern Europe, including Iceland and the Faroe Islands (Di Sabatino et al. 2010) resembles the new species from Kyrgyzstan but differs in having the excretory pore not completely surrounded by a sclerite ring (see Viets 1936, fig. 146b). Sperchon glandulosus cubanicus Sokolow, 1940 ) a subspecies originally described by Sokolow (1940) from the Caucasus, and later on reported from Tajikistan ( Sokolow, 1948), differs by P-2 with a nearly straight ventral margin and a comparatively shorter ventrodistal projection, and the ventral peg-setae on P-4, somehow larger, subdividing the ventral margin of the segment into three unequal parts, distal part longer than proximal and distal ones (see Sokolow 1940, fig. 69).

Distribution — Kyrgyzstan; only known from a stream near Kalman Ashu village ( Fig. 7A ; Fig 18E in Pešić and Smit 2020) in the Tien Shan mountains at an elevation of about 1,600 meters.

Figures

Figure 1. Sperchon krameri sp. nov., ♂ paratype. Dorsum. Inset: integument papillae. Scale bar = 100 µm.

Figure 2. Sperchon krameri sp. nov. (A, C, ♀ holotype; B, ♂ paratype). A – coxal and genital field; B – IV-leg; C – palp, medial view. Scale bar = 100 µm

Figure 3. Sperchon krameri sp. nov., ♂ paratype. A – idiosoma, ventral view; B – photograph of ejaculatory complex; D – palp, lateral view; E – gnathosoma and chelicera. Scale bars = 100 µm.

Figure 4. Photographs of palp. A – Sperchon grigorievka, ♂, KR8 Chon-Kemin NP, upper part of stream near Ashu resort; B-C S. krameri sp. nov. B – ♂, KR8 Chon-Kemin NP, upper part of stream near Ashu resort; C – ♀, KR7 Chon- Kemin NP, stream near Ashu resort.

Figure 7. Photographs of sampling sites: A – KR7 Chon-Kemin NP, upper part of stream near Ashu resort (locus typicus of Sperchon krameri sp. nov.); B – KR27 River along the road to to Som Kul Lake (locus typicus of Atractides magnisetus sp. nov.). Photos by V. Pešić.