AN OVERVIEW ON THE SUBTERRANEAN FAUNA FROM CENTRAL ASIA

Survey of the aquatic subterranean fauna from caves, springs, interstitial habitat, wells in deserts, artificial tunnels (Khanas) of five countries of the former URSS (Kazakhstan, Kyrgyzstan, Tadjikistan, Turkmenistan, Uzbekistan) located far east the Caspian Sea. The cave fauna present some originalities: - the rich fauna of foraminiferida in the wells of the Kara-Kum desert (Turkmenistan); - the cave fish Paracobitis starostini from the Provull gypsum Cave (Turkmenistan); - the presence of a rich stygobitic fauna in the wells of the Kyzyl-Kum desert (Uzbekistan); - the rich stygobitic fauna  from  the hyporheic of streams and  wells around the tectonic Issyk-Kul Lake (Kyrgyzstan); - the eastern limit of the European genus Niphargus from the sub-lacustrin springs  on the eastern shore of the Caspian Sea (Kazakhstan); - the presence of cave fauna of marine origin. Approximately 96 stygobionts, 9 stygobionts/stygophiles and 3 troglobionts are recorded.


II Karsts, caves and artificial galleries (kiarizs)
Several features characterize the karst of Central Asia: -Arid and ultra arid climate in relation to the continental position of Central Asia and the barriers to the influence of summer mousson. The result is the poor contemporary development of limestone karst; -A specific central Asia arid karst: -epikarst characterized by scarcity of dolines and density of fissures near the surface; -development of evaporate karst (gypsum, salt, with spectacular evaporate karsts; -Hydrothermal or sulfuric acid generation of much caves. Caves of these types are reported from the Tien Shan, Pamir, Kopetda; -Caves developped in some mountainous zones where local conditions create higher precipitations; The relief range from lowlands near the Caspian, to the high plateau of Pamir and the highest mountains of the Tien Shan. Central Asia can be divided in four large regions: the Turansky plain, -the plains and low mountains of central Kazakhstan, -the Caledonian and Hercynian mountains of the Tien Shan, -the Alpin mountains of the Kopetdag and Pamir (Klimchouk, 2004).
The Turansky Plain is a vast desert region which contents carbonates and evaporates of Mesozoïc and Cenozoïc ages. It is occupied by the large sand deserts of Kara-Kum, Kyzyl-Kum and Mujunkum.
Some small caves are present: the longest is Sarykamyshskaya (200 m long) and the deepest is the shaft Bolojuk (-120 m). In the eastern part of the Turansky Plain, carboniferous gypsum and limestone karst are reported in the Betpak-Dala desert and the Chujsky region. The Central Kazakhstan consists of plains and low hills broken by wide valleys and depressions. Most of the territory consists of dry steppes, with salt lakes in the northern region, and deserts to the west and south. Deposits of bauxite and phosphorites are associated with the Upper Devonian and Carboniferous limestones, often heavily karstified at depth, with high level of porosity and karst water. In the eastern region, larges caves were formed by sulfuric acid dissolution. The Tien Shan is a block folded region during the Caledonian and Hercynian orogenies, regenerated during the Alpine cycle. It strechtes east to west for around 3,000 km through Uzbekistan, Tadjikistan, Kyrghyzstan and north-western China. The highest peaks exceed 7,000 m. Thick and extensive Paleozoic carbonated rocks are widespread, Mesozoic and Cenozoic sediments fill depressions.

Caves
To the north of the Fergansky depression (Fig. 2B: 17), karst and caves are described from the Ugamsky and Pskemsky ranges; the largest caves are: the Zajdmana Cave 830 m length, -506 m depth, the Uluchurskaya Cave, 1,500 m and -280 m.
Many karst massifs lie south and southwest of the Fergansky depression. There are many small hydrothermal caves and some larger such as: Kun-Ee-Gout (3,000 m long), Pobednaja Cave (1,480 m long), and Fersman'Cave (-220 m deep). Numerous caves are reported from the salt and gypsum karst in the Kysyl Dzhar Mountains.
Over 100 shafts and the Kievskaya Cave (-990 m deep) were explored in the Kyrktau plateau, a karst of the southern Tien Shan.
The Pamir Mountains are mainly situated in Tadjikistan. The eastern part is a high upland with arid climate, the floor of valleys at 3,600/4,000 m a.s.l., the mountains rising 6,000 m a.s.l. The western part is a series of ranges that rise to 1,500/3,500 m above the bottoms of valleys at 1,500/2,500 m. The highest peaks rise to over 7,000 m in the central and northern mountains.
Limestones of Silurian, Devonian, Carboniferous and Triassic ages have extensive outcrops. The most notable site is Rangkulskaya Cave in Triassic limestones at 4,600 m a.s.l., 2,050 m of passages mapped, with remnants of an underground glacier.
Gypsum karst is known at several high altitude and gypsum caves in the Petra Pervogo range. Salt karst is known on the Khodja-Mumyn dome which rises up 900 m above the surrounding plain. Several caves are reported in the dome: Dnepopretovskaya (2,500 m length), Komsomolskaya (1,800 m), Chjudo (870 m) and Vershinnaja (338 m) (Klimchouk, 2004).

Figure. 4
Schematic diagram showing the kiariz (khana) concept. 1 = Mother well; 2 = excavation debris (soil crater); 3 = vertical shafts; 4 = kiariz gallery; 5 = land surface; 6 = outlet; 7 = storage tank; 8 = irrigation land (After modified). Kiarizs are present in Tadjikistan, Turkmenistan and Uzbekistan. They are artificial subterranean galleries dug in desert zones to reduce evaporation. They collect water from mountains or foot hills, for alimentation or irrigation. Khana wells are 1.1 to 22 m depth, the water from 0.5 to 9 m depth, the temperature from 12 to 22°C, the pH of 7.2/7.5; water Na Cl or Na-SO4 type. varies from dry continental to subpolar climate.
The country has about 2,000 lakes, mostly located between 3,000 to 4,000 m a.s.l., the three largest are the Issyk-Kul, Son-Kul and Chatyr-Kul.
The Issyk-Kul Lake (Fig. 2B, 5A-B) lies in the north-eastern part of the territory, it is the second largest mountain lake in the word after the Titicaca: 1,606 m a.s.l., length 179 km, wide 60 km, depth -668 m. The Issyk-Kul area is a tectonical depression bordered by convergent faults (Fig. 5a) and in the north by the Kungey Ridge (4,770 m a.s.l.), in the south by the Terskey Ridge (4,502 m and 5,216 m a.s.l.). The Miocene and Pliocene mark periods of intensive orogenic uplift. The Issyk-Kul depression has been occupied by lake since early Neogene (Voskresenskaya, 1983), the present lake has existed since mid Pleistocene about 700,000 years ago (Trofinov, 1990). During the Holocene the water level of the lake dropped to 110 m below the present level as indicated by underwater terraces, submerged canyons, river channels. In the first half of the 19 th century the lake level rose to 1,622 m, since it has gradually dropped towards its current 1,606 m level.  Bowman et al., 2004). B (lower) Sketch of the Issyk-Kul Lake, and its rivers in adjacent lands (After Jankowskaja, 1972;modified). The lake is fed by about 100 rivers and mountain streams, all fed by ice caps on the surrounding mountains. Littoral plateforms are mainly located on the eastern and western sides of the lake.
The climate is continental. A strong gradient of precipitation exists from the east with 720 mm/year to the west with 120 mm/year.
Intensive survey of the interstitial and karst spring subterranean fauna in the Issyk-Kul area has been particularly carried out along the shore of the lake and in the rivers, managed by the Choktal Biological Station.

Tadjikistan
It is a landlocked country and the smallest in Central Asia. Plateau and mountains of the Pamir cover more than 90% of the country, and more than 50% of the territory is over 3000 m a.s.l. The lowest area lies in the northern part of the Fergana Valley and in the southern Kofernibon and Vakish valleys which rivers form the Amu Darja. There are more than 900 rivers, and glaciers on the Tadjikistan's mountains, they were an important source of runoff for the Aral Sea.

Turkmenistan
It has an area of 488,000 km 2 . It is bordered by Kazakhstan to the northwest, Uzbekistan to northeast, Afghanistan to the southeast, Iran to the south. The west frontier borders the Caspian Sea, along 1,758 km.
Kara-Kum desert. The center of the country is covered by the arid Turansky depression and the Kara-Kum desert which represent 80% of the Turkmenistan. The Kara-Kum desert covers 350, 000 km 2 and consists of dunes and barkhanes, clayed desert zones (fatines) and salt zones. The Kara-Kum was a great bay of the Akchagilian Sea ( Fig. 9) during the late Pliocene and some periods in the Pleistocene. The sand of the desert contains crusted calcareous thallous of the Algae Melobesia sp. which is still living in the Caspian. The last connection with the Caspian Sea and the Aral Sea was in the early Pleistocene (the Baker Age) (Starobogatov, 1994).
The mountainous areas. They consist of the Great Balkan Range in the west, rising 1,880 m a.s.l., and the Koytendag Range on the southeastern border with Uzbekistan. The highest summit is the Ayrybaba (3,137 m). The Amu Darja River flows near and along the northeastern border with Uzbekistan.    Olteanu &Jipa, 2006, simplified, andafter Popov et al., 2004). (See the location of the Akchagilian Basin).
The Kugitangtau mountains (50 km long) along the frontier to Turkmenistan and Uzbekistan are the karst region the most explored. The climate is semi-desert with rains for only short periods in spring and autumn. Flowing water in caves is unusual and except a few isolated pools, thus caves are dry. The temperatures in caves vary with altitude, from 17°C in the Geophyszicheskaya Cave, to 22° C in southern part of the Promeszutochnaya Cave. Locally in some part of caves there are a high level of H 2 S and CO 2 and sometimes radon .. This region is a part of a paleokarst area, perhaps of Middle Cretaceous age, rejuvenated during the Alpine orogeny and invaded during the Middle Quaternary by thermal waters which deposited calcite, fluorite and metallic sulfides. Post thermal and re-working of these deposits has produced a great number of mineral species and great variety of speleothems forms (Maltsev & Self, 1992).

Caves
The most known and longest cave is the Cupp-Coutunn cave system located in Upper Jurassic limestone in the south West zone of the lower Plateau of the Kugitangtau mountains ridge, in eastern Turkmenistan ( Fig.  6: 2); see topography in Self, 2004). The total length of the cave system exceeds 80 km, including 57 km for the complex Cupp-Coutunn -Promeszutochnaya Cave. It is internationally famous for its mineralogy (sauconite, fraipontite) and with very high aragonite and calcite speleothems ( Fig. 8) (Maltsev & Self, 1992;Maltsev, 1997;Self, 2004).
Much An aven, where pigeons built their nests in walls, give access to the cave, approximately 450 m long, which consists of two galleries, with gysum boulders, guano and brackich lakes on the floor, 2-2.5 m depth. The salinity of the water is relatively high (11, 8 g/l of Cl-Na, pH = 7.8). According to Birstein and Ljovuschkin (1965) this level of salinity cannot related to presence of ancient sea on the territory, the nearest marine deposits are 300 km far the cave. Probably the salinity occurred from water flowed upon layers of salt.
The exploration of the Kaptar-khana Cave begun in summer 1963 by a group of speleologists of Moscow, then in November 1963 by the biospeologist S. Ljovuchkin who published in 1969 a short report mentioning the Psocoptera Psyllipsocus ramburii. Starobogatov in 1972 described the cave gastropod Pseudocaspia ljovuchkini. Sendra. Sket and Stoev explored the cave in 2015 and described in 2017 the first troglobiotic Campodea Turkmenocampa mirabilis, and collected undetermined spiders, springtails, crytophagid beetles, parasitic flies.
The cave lakes are inhabited by a fauna from marine origin: foraminifers, gastropods, copepods and isopods. Based on geologic data the two biologists don't considered this fauna as a relict fauna from the Tertiary Sea, but they played either for a more ancient origin or for a dispersion far from the marine transgressions. During the Paleogene the territory was below the Turan Sea (Eastern Paratethys), which began to regress in early Miocene (Popov et al., 2004). During the Pliocene the Akchagilian transgression extends far East ( Fig. 9) but the Kugitangtau Mountains remain out of the sea.
Karst thermal spring. In the southern part of the Kugitangtau is located the thermal karst spring Kainar (Khodja-Kaynar in Birstein & Ljovuschkin, 1965), 1000-1500 l/s. Stygobiotic Hydrobioidea, Stenasellidae and Bogidiellidae were collected from this spring. 50 km beyond exists another spring, 30 l/s, characterized by a high H 2 S level.
Climate: the main part of the country has a climate mostly arid subtropical.

Uzbekistan
Uzbekistan has an area of 447,000 km 2 , completely surrounded by landlocked countries: Kazakhstan and Aral Sea to the northwest, Tadjikistan to the southeast, Kyrghyzstan to the northeast, Turkmenistan to the southwest and Afghanistan to the south. It consists of endoreic basins, a vast desert (Kyzyl-Kum), mountains and intensively cultivated and irrigated land in valleys and oases. The highest point is the Khazret Sultan (4,463 m a.s.l.) in Shurkhandarya Province, on the border with Tadjikistan. For 1984 to 2013 the explorations of caves is carried out by Russian, Spanish, English, Italian and German speleological groups in the Baisun Tau Mountains, in the Surkhandar'inskii region (Tsurikhin et al. 2012(Tsurikhin et al. , 2013(Tsurikhin et al. , 2014. The Baisun Tau range is located in southern Uzbekistan (around 67° E and 38° N), it strechtes 50 km from southwest to northeast, and consists of two mountainous ranges, the Kemen'Chapty and the Hodja-Gur-Gur-Ata, with absolute altitudes ranging between 3,500 and 3,900 m.

Caves
On the Hodja-Gur-Gur-Ata the caves open in high altitude, between 3,200-3,750 m a.s.l. and usually at different elevation on walls of clifs. The speleological potential of the region is very high, and many systems could be connected. The entrances lying at altitudes of 3,200-3,800 m and the groundwater discharge occurring through springs, the largest spring located at 1,400 m a.s.l., the difference between cave entrances and spring exceeds 2000 m.
The Festival'naya Cave found and explored for 1985 was the main focus of cavers and by 1990 it had became with connection the Ledopadnaya-Kozlinaya Cave, the Festival'naya-Ledopadnaya caves system. Now, the Festival'naya-Ledopadnaya caves system (16 km of galleries and -625 m) represents the eastern part of the Central Karst System of Hodja-Gur-Gur-Ata which in 2013 includes six entrances (Dark Star, Capricorne oned, Cancro, Red Dwarf and Vino Rosso) with 9,537 m of surveyed passages to a depth of -858 m. In the Dark Star, temperature ranges from 0°C to 5°C, ice-crystal on walls and frozen lakes are presents.
On the neighbouring Surkhan Tau range, the Ural speleological club with English and Spanish has explored the Boï Boulok Cave, -1,415 m deep.

III Subterranean fauna
Subterranean fauna (Table 1) was described from caves, khanas, springs, interstitial, from wells in Kara-Kum desert, in spring, wells and interstitial around the Issyk-Kul Lake of Kyrghyzstan, near the Choktal Biological station, and from subterranean habitats in other zones: Kyzyl-Kum desert, mountainous range (Fig. 2).

RHIZOPODA FORAMINIFERIDA
About 4,500 taxa of Foraminiferida are known, among them more than 3,500 are fossil forms. They inhabite mainly the benthos of tropical seas with normal salinity, some others the brackish water, and a few continental freshwater or slightly brackish; the latter are estimated marine relicts (Golemansky, 1994). Brodsky (1928Brodsky ( , 1929 for the first time signalized presence of living stygobiotic foraminiferida in wells in the Kara-Kum desert, then Nikoljuk (1945Nikoljuk ( , 1948Nikoljuk ( , 1958 and Mikhalevich (1976) found in subterranean waters of the Kara-Kum desert several genera of Foraminiferida. According to authors these Foraminiferida inhabite the subterranean aquifer of the Kara-Kum and can be collected in wells. Other species, Borovina zernovi Schmalhausen (= Entzia), Miliammina sp., Trochamminita sp. were found by Birstein and Ljovuschkin (1965), then Birsteiniolla macrostoma Jankowskaja & Mikhailevich, 1972 in the Kaptar-Khana Cave, in brackich water (11,68 mmg/l). Borovina zernovi is probably widespread in the subterranean water of the country because theques has been found in many sites (Fig. 12).
All other species in Table 1 were found in wells of Kara-Kum, except Elphitiella sp. found in interstitial of southern beach of the Issyk-Kul Lake (Jankowskaya, 1966).
In 2010 Atullaev and Stadnichenko have published the distribution of aquatic molluscs related to their habitats. From springs they recorded: Bucharamnicola, Kainarella, Martensamnicola, Pseudocaspia, Turkmenamnicola and Valvatamnicola, we add Cincinna, Melanoides, Sogdamnicola and Tadzhikamnicola. All species of Kainarella and Melanoides and some species of Cincinna and Pseudocaspia were collected in hot springs (Fig. 15).
On Table 1, 15 stygobionts and 10 possible stygobionts are recorded, 68% collected in springs, several known only by shells.
The ecological status of molluscs collected in springs is sometimes dubious.

COPEPODA
Twelve genera have stygobiotic species or stygobiotic populations in Central Asia: Cyclopidae (3 genera, 4 species), Harpacticoidae (9 genera, 17 species). 80% of the species have been sampled in interstitial hyporheic and phreatic in the Kuldzhuktau and Muratau Mts, south Khyzyl-Kum desert, and on the shore of the Issyk-Kul Lake.

Stenasellidae
Stenasellus asiaticus Birstein & Starostin is the alone species known in Central Asia, found in the thermal spring Khodza-Kajnar and from the Cupp-Coutunn Cave system were is common. Body pink, colored by hemolymphatic pigments. Lepidocharontidae Three species of Microcharon are recorded from subterranean water of Central Asia: M. kirghisicus Jankowkaya from sand and gravel interstitial near the Issyk-Kul Lake; M. halophilus Birstein & Ljovuschkin (fig. 15) inhabites the brackish lake inside the Kaptar-Khana Cave; Microcharon sp. from hyporheic of a dry valley in southern Kyzyl-Kum desert. All species present a strong thigmotactisme.

ACARI
Four stygobiont Limnohalacaridae are known in Central Asia: Soldanellonyx chappuisi Walter (Fig. 11C), anophthalme as all the Soldanellonyx, from interstitial of two tributaries of the Issyk-Kul Lake; Parasoldanellonyx parviscutatus (Walter) stygobiont from hyporheic in southern Kyzyl-Kum desert; two stygobionts of the genus Lobohalacaruswere collected in wells in Kuldzhukutau and Nuratau Mts. Hydryphantidae Tadjikothyas connexa Sokolow stygobiont from a spring in the canyon Kandera, N Tadjikistan. Aturidae Kongsbergia sp. stygobiont from a spring in southern Uzbekistan.

DIPTERA
Larvae of almost 40 genera of Chironomidae and Culicidae have been collected from water of subterranean habitats in Central Asia (Pankratova, 1972

TERRESTRIAL HYPOGEAN FAUNA
Cave terrestrial fauna is a few known, relatively to the aquatic fauna.
Two subtroglophile genera of Lepidoptera and Diptera and one subtroglophile beetle of the genus Cholevinus are collected in the entrance of caves.