A checklist of the water mites of Central Asia with description of six new species (Acari, Hydrachnidia) from Kyrgyzstan

A survey is given of our state of knowledge on the water mite fauna of Central Asia. As is documented in Table 1, documentation of this fauna is biased towards species living in standing waters. The present study is based on the analysis of all available bibliography and material collected in July 2013 during a joint collecting trip of the authors in Kyrgyzstan. Six species of water mites are described as yet new to science, representing the families Hydryphantidae ( Wandesia albertii n. sp. ), Torrenticolidae ( Torrenticola kyrgyzica n. sp. ) and Hygrobatidae ( Atractides grigorievkae n. sp. , A. manasi n. sp. , A. alaarchaensis n. sp. and A. sonkulensis n. sp. ) Diagnosis Female (Male unknown). Idiosoma small (L 1500 μm); Cx-IV reduced, with medial part not reaching medial part of Cx-III; P-4 slender, L/H ratio 3.7; P-5 without a flagellar seta; basal segment of chelicera curved; no visible pairs of setae inserting in the membranous integument around gonopore; Ac-1 much smaller than posterior pairs of acetabula; III-L-6 and IV-L-6 distally slightly enlarged. Body elongated; lateral eyes unpigmented; retic-ulated. Cx-I+II with slightly convex medial margin, broadly medioposteriorly, concave; Cx-I with setae; Cx-II without setae; Cx-III Cx-IV seta each. Genital with three pairs of stalked elongated genital acetabula; between Ac-1 Ac-2 Ac-3 gonopore between first acetabula. dorsodistal

A checklist of the water mites of Central Asia with description of six new species (Acari, Hydrachnidia) from Kyrgyzstan Vladimir Pešić, Harry Smit To cite this version: Vladimir Pešić, Harry Smit. A checklist of the water mites of Central Asia with description of six new species (Acari, Hydrachnidia) from Kyrgyzstan. Acarologia, Acarologia, 2018, 58 (1), pp.165-185. hal-01697409

Introduction
The water mites of Central Asia have been insufficiently studied (Table 1). This region, extending from Afghanistan in the south to Russia in the north and from the Caspian Sea in the west to China in the east, consists today of five countries: Kazakhstan, Kyrgyzstan, Tadjikistan, Turkmenistan, and Uzbekistan. The water mites from Central Asia have been investigated by several researchers, notably Daday (1903), Thor (1909Thor ( , 1930, Ruzskij (1929), and Tjutenkow (1956). Furthermore, in the twenties and thirties of the last century, Iwan Sokolow greatly contributed to knowledge of water mites of this region. He described Torrenticola turkestanica from Uzbekistan (Sokolow 1926); examined the diversity of Bukhara (Sokolow 1928); described Hygrobates kirgizicus from a tributary of the Chui river in the Ortotokoy valley (Tian Shian Mountains) at altitudes of 1700-1800 m (Sokolow 1935); and he described many new species and a new genus (Tadjikothyas) from Tadjikistan (Sokolow 1948). Then, water mites of the region were untouched until 1973 when Jankovskaja described phreatic and spring fauna of northern Tian Shian (Kyrgyzstan) and southern Kyzylkum (Uzbekistan). In the 21 st century, Central Asian water mite research began with the description of two new Sperchon Kramer, 1877 from streams near Bishkek, Kyrgyzstan (Tuzovskij 2003). Recently, Smit (2016) described a new genus (Kazakhithyas) from a rheohelocrene spring from the Tien Shan Mountains, Kazakhstan. Finally, based on morphological and molecular data we described a new Neumania species from a pond near Issyk Kul Lake in Kyrgyzstan and recorded Limnesia koenikei for the first time from this area (Pešić & Smit 2017).
The present study is based on material collected by the authors during a joint collecting trip from 1-15 July 2013 to Kyrgyzstan, a landlocked country in Central Asia, bordering Kazakhstan, Tajikistan, Uzbekistan, and China. In this paper, descriptions of six new species are given.

Materials and methods
Water mites were collected by hand netting, sorted on the spot from the living material and preserved in Koenike-fluid. Specimens were dissected as described in Gerecke et al. (2007) and slide mounted in Hoyer's medium. Morphological nomenclature follows Gerecke et al. (2016). Holotypes and paratypes of the new species are deposited in the Naturalis Biodiversity Center in Leiden (RMNH). The composition of the material is given as: males/females/deutonymphs. All measurements are given in μm. The following abbreviations are used: Ac-1 = first acetabulum; asl. = above sea level; Cx-I = first coxae; dL = dorsal length; H = height; I-L-4-6 = fourth-sixth segments of first leg; L = length; lL =lateral length; mL = medial length; NP = National Park; P-1-P-5 = palp segment 1-5; S-1 = proximal large ventral seta at I-L-5; S-2 = distal large ventral seta at I-L-5; Vgl-1 = ventroglandularia 1; W = width.
Diagnosis -Female (Male unknown). Idiosoma small (L 1500 μm); Cx-IV reduced, with medial part not reaching medial part of Cx-III; P-4 slender, L/H ratio 3.7; P-5 without a flagellar seta; basal segment of chelicera curved; no visible pairs of setae inserting in the membranous integument around gonopore; Ac-1 much smaller than posterior pairs of acetabula; III-L-6 and IV-L-6 distally slightly enlarged.
Legs Discussion -The new species is morphologically most similar to Wandesia reducta, a species described by Tuzovskij (1987) based on three females and a larva from Magadan region in the Far East of Russia and later on reported by Pešić et al. (2015) from South Korea. Recently Semenchenko (2016) described the male of this species. Both species share P-5 without a flagellar seta and Cx-IV reduced, with the medial part not reaching the medial part of Cx-III. The female of W. reducta (in parentheses data taken from Tuzovskij 1987) differs in larger idiosoma dimensions (L 2280-2610 μm), the genital field with 3-5 pairs of small setae located around the anterior half of gonopore, P-4 shorter (L 65 μm) and stouter, and III-L-6 and IV-L-6 distally strongly enlarged (see Tuzovskij 1987, figure 3I).
Description -Female -Idiosoma elongated; dorsal shield without colour pattern; gnathosomal bay U-shaped, proximally rounded; Cxgl-4 subapical, only slightly posterior to Cx-I tips; medial suture line of Cx-II+III relatively long; suture lines of Cx-IV extending posteriorly beyond posterior margin of genital field, laterally curved; genital field pentagonal in shape; excretory pore on the level with Vgl-2, both slightly away from the line of primary sclerotization; gnathosomal rostrum long ( Figure 2E), ventral margin in lateral view curved; P-2 nearly equal in length as P-4, ventral margin of P-2 distally with a laterally compressed, longish (>30% of ventral margin), anteriorly directed and apically serrated hyaline extension and a very short seta laterally at base of projection; P-3 with a shorter, subrectangular, apically serrated ventrodistal projection, and a moderately long seta laterally at base of projection; P-4 slender, with ventral tubercles pointed and separated, bearing one long and three short setae ( Figure 2D).
Discussion -The combination of a flanged palp with subapical Cxgl-4, only slightly posterior of Cx-I tips, makes the new species similar to Torrenticola malaisei (Lundblad, 1941), T. prionipalpis (Lundblad, 1941), and T. lamellifera (Lundblad, 1941), all known from Burma (Lundblad 1969). The latter species has been synonymized by Wiles (1997) with T. malaisei, but recently this synonymization has been rejected by Pešić et al. (2012). Females of T. malaisei and T. lamellifera can be distinguished from those of T. kyrgyzica by their more roundish idiosoma, a short medial suture line of Cx-II+III, and a longer ventral seta on P-3 (see Wiles 1997). Moreover T. malaisei has a stouter P-4. Torrenticola prionipalpis (Lundblad, 1941), known from a single male, has a roundish idiosoma, a more slender P-4, a smaller ventral seta on P-2, and P-4 ventral tubercle, ending in two tips separated by a concavity, with four short setae (see Wiles 1997).
Etymology -Named after the country where the new species was found.
Distribution -Kyrgyzstan; known only from the locus typicus ( Figure 10D). Diagnosis -Female (Male unknown). Integument striated; suture line Cx-III and -IV in its medial part directed posteriorly; P-3 ventral margin slightly convex with one (occasionally two) ventral seta; P-5 short; excretory pore smooth; acetabula in a slightly curved line; I-L-5 with S-1 ending in a bluntly pointed tip.
Discussion -The new species is provisionally assigned to the subgenus Polymegapus K. Viets, 1926, which was considered by Gerecke (2003) to be a monophyletic clade. The new species does not fit the diagnosis of the subgenus given by Gerecke et al. (2016) in the following features: 1) suture line Cx-III and -IV in its medial part directed posteriorly, 2) Cx-4 without triangular laterocaudal extensions of secondary sclerite, 3) I-L-5 with ventral margin shorter than dorsal margin, 4) P-5 short and less slender, and 5) excretory pore unsclerotized. The combination of the characters given under 1), 3) and 5) make the new species close to A. putihi Wiles, 1991 from SE Asia (Wiles 1991, Pešić & Smit 2009, Smit & Pešić 2014. The latter species differs in genital plates, restricted to the level of the postgenital platelet, with the acetabula in a triangular arrangement, P-3 ventral margin slightly concave, without setae and IV-L-5 with 2 swimming setae. Probably A. grigorievka n. sp. represents an early derivative member with the typical palp and I-L not yet fully developed. Etymology -Named after the canyon where the new species was found. The name is a noun in apposition. Distribution -Kyrgyzstan, known from one rheocrenic ( Figure 10C) and one rheohelocrenic spring ( Figure 10G).
Discussion -The new species resembles the hyporheobiontic Atractides pygmaeus (Motaş & Tanasachi, 1948) in many points of view: small dimensions (idiosoma L < 500 μm), unsclerotized excretory pore, slightly modified I-L-5/-6 with short and bluntly pointed S-1/-2 and the presence of well pronounced denticles accompanying the ventral setae of P-4. Atractides pygmaeus differs in having sclerotized muscle attachments, and fused Vgl-1/2, P-2 forming an acute distoventral angle, without projection and acetabula arranged in a weakly curved line (see Gerecke et al. 2016). These clear cut differences, together with the fact that in the male no particular sexual dimorphism is to be expected, justifies the description of the new species based on a single female specimen only.
Etymology -Named after Manas, the heroic warrior featured in one of the longest epic poems in the history of the world "The Epic of Manas" (Kyrgyz: Манас дастаны).
Diagnosis -Coxae without sexual dimorphism (in both sexes Cx-I+II close to Cx-III+IV at their touching edges, but not forming a coxal shield, Vgl-3 not fused to Cx-IV); P-2 ventral margin convex, without distal projection, P-3 with one seta each on medial and lateral surface extending beyond ventral margin of segment; in male S-1-2 separation 19-21 μm.
Deutonymph: Provisional genital field with two pairs of acetabula ( Figure 7C); P-2 ventral margin convex, P-3 without seta on medial and lateral surface.
Discussion -Due to a similar shape of palp and I-L-5 and -6, the new species is closely   related to Atractides sonkulensis n. sp. (see below) and differs from all other species in having one seta each on medial and lateral surface of P-3. Atractides sonkulensis n. sp. differs in the male in generally smaller dimensions of idiosoma, I-L-5/6 and palps (e.g., idiosoma L < 500 μm, -L-5 dL 145, palp total L < 300 μm), a coxal field merged to an unique plate including Vgl-3, a nearly straight ventral margin of P-2 and a shorter S-1/2 interspace (9-10 μm). In the female A. sonkulensis n. sp. differs in a smaller dimensions of medial suture line of Cx-I+II, genital plates and acetabula, and a relatively longer I-L-6 (L ratio I-L-5/6 1.4).
Etymology -Named after the National Park where the new species was found.