Subterranean Fishes of the World

Generic name misspelt Nemachilus by Pereladov (1989).

Country

Types

Holotype: ZISP 46159 49.5mm SL.

Paratypes: ZISP 46160 3 specimens 36.7mm, 43.6mm, and 47.6mm SL. ZISP (no reference number) 44.2mm SL. ZMMU P16030 and P16031 56.8mm and 61.0mm SL.

This species is the type species by monotypy of the subgenus and genus Troglocobitis.

Distribution

Known only from the type locality: Provull Gypsum Cave, 45 km from the railway station at Tcharchanga and 60 km from the town of Gaourdak, in the mountainous area of Kugitangtau (also known as Koytendag), Lebap Province, Turkmenistan (37^o37'37"N, 66^o21'09"E, Kottelat 2012:134 = 37.596778N, 66.405500E, alt. 360m). Also known as Suw Oyuk (Suuvoyuk) (Sidorov et al. 2018, Zimmerman, Jones and Ball 2019). Despite a search of other similar sites in the same area Smirnov (1983) did not find any other locations for this species, and neither did Zimmerman, Jones and Ball in 2013-2015 (Zimmerman, Jones and Ball 2019). Provull Cave is about 5 km SW of the Cupp-Coutunn Cave in a gypsum karst (Maltsev and Self 1992)

Habitat

Collected "in a karst collapse which opened in a region of subterraneous water flow” (Parin 1983), December water temperature 24^oC (Smirnov 1983). The animals live in a lake within a gypsum cave and feed on a bacterial film on the surface of organic silt and/or on insect larvae and small Crustacea. This area is under the roosts of birds and bats. The fishes move about within the lake from depths of 4-5m down to at least 58m (Pereladov 1989). In May the water temperature was 19-20^oC and the females were full of ripe eggs.                                                                                                                                             

Systematics

Sufficiently distinct to merit erection of the subgenus Troglocobitis to contain it. Nalbant and Linares (1987) placed this species in the genus Paracobitis (retaining the subgenus Troglocobitis) but without giving their reasons. This was followed in the review paper of Decu et al. (2019). Eschmeyer's Catalogue of Fishes (Fricke et al. 2019) and the authoritative summary of world Cobitoidei (Kottelat 2012) both retain Troglocobitis and this is followed here.

According to the detailed phylogenetic study of Prokofiev (2010) Troglocobitis is sister genus to Paracobitis and both of these together are sister to Iskandaria Prokofiev 2009. All three genera are inluded in the tribe Nemacheilini within the subfamily Nemacheilinae.

Although the formal description of the species was published by Parin (1983) the name is available from Parin and  Dolzhansky (1982).

Biological Notes

The food supply in the cave might result from chemoautotrophic production as well as imported from outside.

The following account was found on a Russian language version of Wikipedia (ru.wikipedia.org/wiki/Койтендагский_слепой_голец) and translated using Google Translate. This text is made available under a Creative Commons Attribution-ShareAlike license. This page was last edited on April 3, 2021.

Koytendag blind charr

Koytendag blind fish, or Kugitang blind fish or Starostin's blind fish (latin name Troglocobitis starostini), is a cave species of ray-finned fish of the family Nemacheilidae. The only endemic fish of the inland waters of Turkmenistan. It is found only in the underground lake of the Suvly-Oyuk karst sinkhole in the Bulak-dere gorge in Kugitangtau, Koytendag, east of the village of Garlyk. The surface of the lake has an area of ​​about 40 m² and a depth of 5-7 m. The water is clean, transparent, salinity is about 5g/l (2.5 g/l of gypsum, including 690 mg/l Ca ++, 210 mg/l Mg++, about 2 g/l sodium chloride), pH = 7.08, water temperature (spring-summer-autumn) is 21–24 °C.

The species was first discovered by the traveler and cave explorer Vladimir Arkadyevich Maltsev (07/14/1957 - 02/15/2014) in 1978 in the waters of a small lake (about 40-45 m² in area and 5-7 m deep), located at the bottom of a deep sinkhole. In November 1981, five fishes were caught and brought alive to Moscow by biologist and speleologist Vadim Yuryevich Dolzhansky, In Moscow they were transferred to ichthyologist Nikolai Vasilyevich Parin for description. In 1983, the biotope was studied by ichthyologist Sergei Smirnov as part of a speleological expedition led by V.Yu. Dolzhansky to study the cave system, called Mitya. The new species was described under the name Nemacheilus (Noemacheilus) starostini by Parin in 1983. The first article about the discovery of fish was written jointly by V.Yu. Dolzhansky and N.V. Parin in 1982 and published in the journal "Priroda". The species is named after V. I. Starostin, one of the organizers of systematic hydrobiological research in Soviet Central Asia.

The name has now been changed to Troglocobitis starostini. Before the discovery of this species, it was believed that there were no real troglobiont fish in water bodies on the territory of the former USSR.

A small fish with a maximum body length of up to 7 cm. Completely devoid of eyes. The color is yellowish-pinkish, which is due to the absence of pigments in the skin. Scales and swim bladder are absent. The body is elongated, almost cylindrical. Under the skin there is a continuous fatty layer.

Range and habitat

It is a narrow area endemic. The area of ​​distribution of the species includes a desert flat area at the foot of the Kugitangtau (Koytendag) mountain range near the village of Garlyk (Karlyuk) in the southeast of Turkmenistan. In this foothill area, there are several dozen sinkholes 10-20 m deep, which are the result of the presence of an underground hydraulic system, fed mainly by water runoff from the Koytendag mountain range. All of these dips are partially or completely water-filled dome-shaped dissolution cavities in gypsum-anhydrite sequences of the Kimmeridgian-Titonian age (Late Jurassic). The diameter of the cavities can exceed 100 m. The explored depth of the Suvly-Oyuk sinkhole is more than 70 m. The main water artery (Kugitang-darya) is fed in the upper reaches by karst bicarbonate-calcium waters, but along the way it receives bitter-salty springs of its right bank. In the middle reaches, most of the runoff goes into underground channels of gypsum-anhydrite strata. Therefore, the water in the dips is gypsum-chloride-sodium with a mineralization of up to 5 g/l. The lower course of the Kugitang Darya is completely underground with a runoff to the Amu Darya. Several hydrogen sulfide sources are also known. According to V. Maltsev, it was the insurmountable hydrogen sulfide barrier that was the reason for the isolation of the blind fish. The only known habitat of the species is an interconnected system: a lake at the bottom of the sinkhole, which, at a depth of 15 m, is connected by a narrow passage with a vast underground cavity filled with water. The upper part of the cavity has a domed shape, at a depth of 30 m its diameter is about 100 m. This cavity is probably the main habitat of this species. The entrance lake is probably a seasonal feeding place for fish, since the food base in it is much richer than in the underground cavity. The sun's rays are able to reach the entrance lake, and bats and pigeons settle on the walls. Their droppings enter the lake and contribute to the development of aquatic vegetation – filamentous algae and water mosses that cover the stones on the bottom and walls. Blind cave isopods and gastropods have also been found in the lake. The water in the lake is mineralized (about 3 g/l), quite transparent and has a constant temperature of 22-24°C . In neighboring caves, identical in water chemistry, the blind fish is not found. The original, not blind, species is found in the Kugitang-darya.

Biology

The biology of the species is poorly understood but it is certainly a troglobiont. It probably feeds on various organic remains, since fish of this species usually graze on the bottom of the lake, or scrape organic matter off the walls of the sinkhole. In spring, when a large amount of organic matter enters the underground hydraulic system along with the runoff of water, fish rarely swim out into the open inlet lake. In autumn, when there is much less food in the underground cavity, they often swim out into the entrance lake. Reproduction has not been studied. In May-June 2015, the RSPB expedition caught 7 specimens, 2 of which were taken for a complete species and genetic description.

Numbers and protection

The number has not been determined. In the underground cavity, it is estimated at several hundred adults. In the inlet lake, it varies depending on the season or features of the year.

In the first years of the discovery of the species (1978-1983), up to 150 individuals could be found in the entrance lake. In early December 1983, 60 individuals were counted. In September 2003, no fish were found, and in October 2004, 20 individuals were recorded, in 2010 - 12 individuals.

The data indirectly indicate a trend in population decline. The main limiting factors are habitat disturbance and uncontrolled fishing. There are cases when, in the first half of the 1980s, fishes were sold at the bird market in Moscow and Novosibirsk.

The species is listed in the Red Book of Turkmenistan. It is protected in the Garlyk reserve of the Koytendag nature reserve, which in practice does almost nothing for its conservation.

References

1. Nemacheilus starostini. The IUCN Red List of Threatened Species. (Accessed: June 5, 2019).

2. Annabayramov B. and others. The Red Data Book of Turkmenistan. Vol. 2: Invertebrates and vertebrates. - 3rd ed., revised. and additional - Ashgabat: Ylym, 2011. - 384 p.

3. Salnikov V. B. The current state of the ichthyofauna of Koytendag water bodies and measures for its protection // Proceedings of the scientific-practical conference dedicated to the 75th anniversary of the Khazar State Reserve. - Ashgabat-Turkmenbashi, 2008. - S. 149-152.

4. Reshetnikov Yu. S., Kotlyar A. N., Russ T. S., Shatunovsky M. I. Five-language dictionary of animal names. Fishes. Latin, Russian, English, German, French. / under the general editorship of acad. V. E. Sokolova. — M.: Rus. yaz., 1989. - S. 155. - 12,500 copies. — ISBN 5-200-00237-0.

5. Parin N. V. Noemachelius (Troglocobitis) starostini sp. n. (Osteichthyes, Cobitidae) — a new blind fish from the underground waters of Kugitangtau (Turkmenistan) // Zoological Journal. - 1983. - Issue. 1. - S. 83-89.

6. Red Data Book of Turkmenistan. T. 1. Invertebrates and vertebrates. - 2nd ed. - Ashgabat: Turkmenistan. 1999. - S. 146-147.

7. Rustamov E. A., Welch J., Karryeva Sh. B., Vard S. On the characterization of the biodiversity of Koytendag (Turkmenistan) // Selevinia / Editor-in-Chief A. F. Kovshar. - 2014. - T. 22. - P. 111. - ISBN 978-601-7287-17-7.

8. Shaniyaz Menliev. Amazing and rare inhabitants of the Karlyuk caves. Alpagama.org (February 7, 2019). Retrieved: June 6, 2019.

9. Shilin N. I., Pereladov M. V. The Koytendag (Kugitang) blind charr is a rare and vulnerable representative of the cave ichthyofauna // Caves. - 2013. - No. 37. - S. 150-157.

10. In the journal "Science and Life" the surname Stepanov is erroneously indicated: Parin I. Underground fish // Science and Life: Journal, - 1983. - No. 7. - P. 17.

11. Pereladov M. History of one record. Bulak-Dara canyon cave // ​​Neptune. - 2012. - No. 5. - S. 48-54.

12. Pereladov M. V. History of research and modern problems of studying and protecting the fauna of underground hydrosystems in the region of the Koytendag ridge (Kugitang-Tau), Turkmenistan // Turkmen nature: unsolved secrets of Koytendag: materials of the international. scientific conf. - Ashgabat: Turkmenistan, 2012. - S. 337-339.

13. Salnikov V. B. Ichthyofauna of Kugitang reservoirs // Problems of desert development. - Ashgabat, 2006. - S. 18-23.

Museum Holdings

Four other specimens in addition to the type series, probably at IOAS.