GOBIIDAE, Cuvier, 1816

Family GOBIIDAE View in CoL

Genus Babka Iljin, 1927

8. Bigeye racer goby (new English common name) Babka macrophthalma ( Kessler, 1877)

This is a non-commercial but abundant fish species that is endemic to the Caspian Sea ( Bogutskaya et al., 2013). It inhabits the oligohaline and mesohaline areas of the sea and was not previously known from rivers. This species is mainly distributed in the eastern part of the Northern Caspian Sea ( Kazancheev, 1981), while it is more common off the western coast of the Middle Caspian Sea near the mouth of the Sulak River ( Ivanov and Komarova, 2008). It is excluded from the list due to its high abundance and widespread distribution.

Genus Benthophilus Eichwald, 1831

9. Abdurakhmanov’s tadpole goby Benthophilus abdurahmanovi Ragimov, 1978

It is endemic to the Caspian Sea, a non-commercial species with unknown abundance. This species is widespread in the Northern Caspian Sea, especially in its western part and near the Delta of the Volga River ( Kazancheev, 1981). It is also reported from the mouth of the Terek River ( Vasil'eva, 1983). In the western part of the Middle Caspian Sea, this goby is known as far south as Makhachkala and Cape Turaly ( Ragimov, 1978, 1981, 1985). It has been recorded in the Mangistau Region (northeastern and Middle Caspian Sea) ( Chernova and Orlova, 2012). This species was originally described from the east coast of Tyuleny Island in the Northern Caspian Sea. According to Naseka and Bogutskaya (2009) and Bogutskaya et al. (2013), this goby occurs in the Middle and Southern Caspian Sea, but these records have not been confirmed for Iran ( Jouladeh-Roudbar et al., 2015). Due to its widespread distribution and unclear level of its abundance, it was excluded from the list.

10. Baer pugolovka Benthophilus baeri Kessler, 1877

It is a non-commercial and poorly studied fish, an endemic to the Caspian Sea. In the Middle and Southern Caspian Sea, this species is found mainly along the eastern coast from Cape Peschaniy to Esenguly, while along the western coast, it is distributed southwards to Lankaran, with increased abundance in the southern areas. In the Northern Caspian Sea, this species occurs near Tyuleny and Chechen Islands, in the Bakhtemir Furrow, and southwards to Peshnoy Island and the Mangyshlak Peninsula ( Ragimov, 1965, 1977, 1981, 1985; Vasil'eva, 2000; Boldyrev and Bogutskaya, 2007). There is no reliable information on the distribution of B. baeri in Russian waters ( Bogutskaya et al., 2013). This species has been excluded from the list due to its widespread distribution and the lack of threats to this species ( IUCN, 2024).

11. Benthophilus casachicus Ragimov, 1978

This is a marine, non-commercial, poorly studied species, endemic to the Caspian Sea. The majority of reliable records of this species are reported for the eastern Caspian Sea from Cape Peschaniy to Ogurchinskiy Island (Ogurja Ada) at depths of 15-75 m ( Ragimov, 1977, 1978). There is no information on its distribution in Russian waters ( Bogutskaya et al., 2013). Data on the distribution of this species in the waters of the Middle and Southern Caspian Sea ( Naseka and Bogutskaya, 2009; Bogutskaya et al., 2013) have not been confirmed by samples from Iran ( Esmaeili et al., 2018). Recent data ( IUCN, 2024) confirm that B. casachicus is restricted to the eastern coast of the Caspian Sea. It is therefore excluded from the list of the species needing protected in Russian waters.

12. Granular tadpole goby or granular pugolovka Benthophilus granulosus Kessler, 1877

This species is a non-commercial abundant species, endemic to the Caspian Sea. It is widely distributed, including the southeastern part of the Northern Caspian Sea, off the coast of Dagestan and Azerbaijan, off the mouths of the Volga and Ural rivers, and in the lower reaches of the Volga Delta to Astrakhan ( Kazancheev, 1981). Some publications ( Reshetnikov, 2002; Miller, 2004) indicate that the range of this species also includes the coastal areas of all parts of the sea, including Iranian waters. However, an analysis of reliable literature data and collections of ZIN RAS (Zoological Institute of the Russian Academy of Sciences, Sankt-Peterburg, Russia) shows that B. granulosus does not occur along the coasts of the Southern Caspian Sea ( Boldyrev and Bogutskaya, 2007). Before the lowering of the sea level, this species was found along the northern coast of the Buzachi Peninsula from Durnev Island eastwards to the northern part of the Dead Kultuk Bay ( Bogutskaya et al., 2013). It is excluded from the list of species in need of protection due to its wide distribution and high abundance.

13. Grimm tadpole goby Benthophilus grimmi Kessler, 1877

This species is endemic to the Caspian Sea, a deep-sea marine fish inhabiting depths below 100 m, whose range is limited to the western part of the Middle Caspian Sea and the northernmost part of the Southern Caspian Sea from Chechen Island to the Absheron Peninsula ( Boldyrev and Bogutskaya, 2007). This goby is not reported from the Northern Caspian Sea, while it is absent from the coastal waters of Russia in the Middle Caspian Sea ( IUCN, 2024). This species has also been reported from the waters of Kazakhstan in the Mangystau Region ( Chernova and Orlova 2012), while data on its records in the Middle and Southern Caspian Sea are not supported by samples from Iran ( Esmaeili et al., 2018). The species does not require additional conservation measures due to its habitat at depths where human activity is minimised.

14. Caspian stellate tadpole goby Benthophilus leobergius Berg, 1949

This is a marine, widespread but not abundant species, endemic to the Caspian Sea. This goby is thought to be widespread throughout the Caspian Sea ( IUCN, 2024). However, it is known ( Boldyrev and Bogutskaya, 2007; Bogutskaya et al., 2013) that this species does not occur off the eastern coast of the Middle Caspian Sea. In its southeastern part, B. leobergius is known from the waters of Ogurchinskiy Island (Ogurja Ada) and the Gulf of Gorgan ( Esmaeili et al., 2018; Jouladeh-Roudbar et al., 2015). It is also reported from the Safid Rud River ( Abbasi et al., 1999), the southern and southwestern parts of the Iranian coast and as far north as Zyuydostoviy Kultuk in Azerbaijan ( Ragimov, 1965, 1966; Kiabi et al., 1999). The species does not require additional conservation measures due to its widespread distribution, lack of information on current abundance and existing threats to its populations ( IUCN, 2024).

15. Flat-head tadpole goby Benthophilus leptocephalus Kessler, 1877

This species is a deep-sea marine fish found at depths of 30-300 m and is an endemic to the Caspian Sea ( IUCN, 2024). It is mainly found in the Middle and Southern Caspian Sea. In the western part of the Middle Caspian Sea, it is known from the mouth of the Samur River, while in the eastern part of the Southern Caspian, this goby occurs between Turkmenbashi and Esenguli ( Kessler, 1877; Ragimov, 1965, 1977, 1982; Boldyrev and Bogutskaya, 2007). B. leptocephalus has not been observed in the shallow coastal waters of Russia ( IUCN, 2024). This species does not require additional conservation measures due to its habitat at great depths, where human activity is virtually non-existent.

16. Short-snout tadpole goby or short-snout pugolovka Benthophilus leptorhynchus Kessler, 1877

This is a deep-sea marine species found at depths of 40-150 m and is endemic to the Caspian Sea ( IUCN, 2024). It is reliably reported only from the waters off the western coast of the Middle Caspian Sea from the mouth of the Sulak River to the northern part of the Southern Caspian Sea south of the Absheron Peninsula, where it has been rarely observed ( Kessler, 1877; Berg, 1927; Boldyrev and Bogutskaya, 2007). According to Naseka and Bogutskaya (2009) and Bogutskaya et al. (2013), this species occurs in the waters of the Middle and Southern Caspian Sea, but no records of this species have been documented in Iranian waters ( Esmaeili et al., 2018). In the Northern Caspian Sea, this species has not been observed in the shallow coastal waters of Russia ( IUCN, 2024). The species is not currently in need of protection as it inhabits depths where anthropogenic impacts are negligible.

17. Caspian tadpole goby Benthophilus macrocephalus (Pallas, 1787)

This species is a marine, coastal and estuarine, non-commercial, abundant fish, endemic to the Caspian Sea ( IUCN, 2024). It inhabits the entire Northern Caspian Sea, while off the western coast of the Middle Caspian Sea, it is mainly found in the area from Chechen Island to the mouth of the Sulak River and south to the Absheron Peninsula. In the Southern Caspian Sea, this species is known from the Gulf of Gorgan ( Ragimov, 1965; Bogutskaya et al., 2013). It is also reported from the Volga Delta and the mouth of the Ural River ( Kazancheev, 1981). It is one of the most widespread gobies in the Northern Caspian Sea ( Berg, 1949; Ragimov, 1966, 1981; Vasil'eva, 1983, 2000). Prior to sea-level lowering, B. macrocephalus was also recorded in Dead Kultuk Bay ( Svetovidov, 1937). The current level of anthropogenic impact on populations of this species is unclear ( IUCN, 2024). Due to its high abundance, wide distribution and lack of known threats, it does not require additional protection.

18. Small-spine tadpole goby Benthophilus mahmudbejovi Ragimov, 1976

This is a non-commercial marine species, endemic to the Caspian Sea. It is distributed in almost the entire Northern Caspian Sea, while along the eastern coast of the Middle and Southern Caspian Sea, this species is recorded near Cape Peschaniy, Cape Rakushechniy, Cape Kara-Singir, Kenderly Spit, Cheleken Peninsula and Ogurchinskiy Island (Ogurja Ada) ( Reshetnikov et al., 2002; Bogutskaya et al., 2013). It is not abundant in the Northern Caspian Sea as a whole. There were no catches in the eastern part of the Northern Caspian Sea in 2000-2003, during the period of sea desalination ( Stepanova et al., 2004). Boldyrev and Bogutskaya (2007), Naseka and Bogutskaya (2009), Bogutskaya et al. (2013) also reported this species from the waters of the Middle and Southern Caspian Sea, but these data are not confirmed by samples from Iran ( Esmaeili et al., 2015, 2018). This species is thought to be widespread in the Caspian Sea, but current abundance and the extent of anthropogenic impacts are unknown ( IUCN, 2024). This species has been excluded from the list of species in need of additional protection due to its wide distribution, uncertain abundance and unknown threats to its populations.

19. Spiny tadpole goby or spiny pugolovka Benthophilus spinosus ( Kessler, 1877)

This is non-commercial, poorly studied marine species, endemic to the Caspian Sea. It is distributed along the eastern and western coasts of the Middle Caspian Sea and in the southeastern part of the Northern Caspian Sea (from Kulaly Island to the Mangyshlak Peninsula), as well as in the southeastern corner of the sea ( Bogutskaya et al., 2013). This species is quite rare along the western coasts of the Middle and Southern Caspian Sea, and is not recorded in the western part of the Northern Caspian Sea ( Kazancheev, 1981; IUCN, 2024). It is excluded from the list of species needing conservation in Russian waters as it occurs only in the southernmost part of this area, while current threats to populations of this species are unknown ( IUCN, 2024).

20. Ragimov’s tadpole goby Benthophilus ragimovi Boldyrev et Bogutskaya, 2004

This is a deep-sea marine fish, endemic to the Caspian Sea that inhabits depths of 30-200 m ( IUCN, 2024). This species is known from the western coast of the Middle Caspian Sea ( Esmaeili et al., 2015, 2018) and the Southern Caspian Sea from Chechen Island to Astara ( Boldyrev and Bogutskaya, 2007). B. ragimovi has not been recorded in the Northern Caspian Sea, while it has not been observed in shallow coastal areas in Russian waters of the Middle Caspian Sea ( Bogutskaya et al., 2013; IUCN, 2024). Therefore, additional conservation measures are not required for this fish, as it inhabits depths where the impact of human activities is minimal.

Genus Neogobius Iljin, 1927

21. Caspian goby Neogobius caspius (Eichwald, 1831)

This species is a rare marine species, endemic to the Caspian Sea, occurring throughout the Caspian Sea with the exception of the deep waters of the central and southern parts ( IUCN, 2024). It is a target of recreational fishing ( Rustamov and Shakirova, 2013). N. caspius avoids fresh waters and does not enter estuaries ( Ragimov, 1965; Kazancheev, 1981; Abdoli and Naderi, 2009). It is not abundant in the Northern Caspian Sea, but is regularly recorded in this area. An increase in abundance was observed in the western part of the sea in 2003 ( Stepanova et al., 2004; Bogutskaya et al., 2013). The species does not require additional protection due to its widespread distribution, stable abundance and lack of known threats ( IUCN, 2024).

22. Monkey goby Neogobius fluviatilis (Pallas, 1814)

This species inhabits fresh and brackish waters. The native range includes the basins of the Marmara, Black and Azov seas, including tributaries of the Don and Kuban rivers ( Berg, 1949; Svetovidov, 1964; Naseka et al., 2012; Artaev et al., 2021; Moskul, 2021). It has recently invaded the Volga and Oka rivers ( Ivanchev and Ivancheva, 2010; Slynko and Tereshchenko, 2014; Kvach et al., 2021). Since 2012, N. fluviatilis has been recorded in the Baltic Sea basin, including the Pregolya and Neman rivers ( Novozhilov and Gulina, 2023; Shibaev et al., 2024). Due to its widespread distribution, expanding range, increasing abundance and unknown threats to populations ( IUCN, 2024), no additional conservation measures are required for this species.

23. Round goby Neogobius melanostomus (Pallas, 1814)

It is a brackish and freshwater species. Its native range includes the basins of the Marmara, Caspian (whole), Black and Azov seas ( Berg, 1949; Svetovidov, 1964; Vasil'eva, 2007; Bogutskaya et al., 2013; Slynko and Tereshchenko, 2014; Zarei et al., 2022). It has been introduced into the Aral Sea ( Vasil'eva, 2007), but has probably not acclimatised due to the high salinity ( Vassilev et al., 2012). N. melanostomus was introduced into the Baltic Sea (Kaliningrad Region and Gulf of Finland), where it invaded the lower reaches of some rivers ( Vasil'eva, 2007; Novozhilov, 2012; Karaseva, 2022; Yurtseva and Uspenskiy, 2022; Shibaev et al., 2024). It has also been accidentally introduced into some lakes and rivers of the North America (e.g., Ontario and Illinois) ( Kottelat and Freyhof, 2007; Vasil'eva, 2007; Gutowsky and Fox, 2011; Vassilev et al., 2012). Due to its widespread distribution, range expansion, increasing abundance and lack of known threats to its populations ( IUCN, 2024), the introduction of additional conservation measures is not required.

Genus Ponticola Ilijn, 1927

24. Caspian ratan or rotan goby Ponticola goebelii ( Kessler, 1874)

This is an extremely rare marine species, endemic to the Caspian Sea, known mainly from a small number of type specimens ( Kessler, 1874; Pinchuk, 1976; Kazancheev, 1981). Its range mainly covers the western part of the Middle Caspian Sea from Chechen Island in the north to the Absheron Peninsula in the south, but it is also known from the Southern Caspian Sea ( Bogutskaya et al., 2013; Zarei et al., 2022), where it has been recorded near the mouth of the Kura River and in the Turkmenbashi area ( Ragimov, 1977; Naseka et al., 2012; Bogutskaya et al., 2013). No records of this species were observed in the Northern Caspian Sea from 1974 to 2003 ( Stepanova et al., 2004). The species does not currently require any additional conservation measures, as threats to its populations are unknown ( IUCN, 2024).

25. Caspian bighead goby Ponticola gorlap (Iljin, 1949)

This species is a riverine, estuarine and marine fish inhabiting both the Caspian and Azov seas basins. This species is a target of recreational fishing ( Rustamov and Shakirova, 2013). It is mainly found in the sea, especially in coastal waters ( Kazancheev, 1981). P. gorlap is widespread throughout the Caspian Sea and its basin, including the lower reaches of the Volga River to Astrakhan, small rivers of Dagestan, Azerbaijan and northern Iran, the Kura River to Mingachevir, lakes of the Lower Terek, Yasga Lake, and lower reaches of the Ural River ( IUCN, 2024). This species is relatively rare in the Northern Caspian Sea, as well as near the western and eastern shores of the Middle and Southern Caspian Sea, where it is relatively rare, except off the Absheron Peninsula ( Bogutskaya et al., 2013). Its abundance in the Middle Caspian Sea has increased slightly following the desalination of the sea due to an increase in river discharge ( Stepanova et al., 2004; Bogutskaya et al., 2013). Currently, this species does not require additional conservation measures due to its increasing abundance and lack of threats to its populations ( IUCN, 2024).

Genus Proterorhinus Smitt, 1900

26. Tubenose goby Proterorhinus nasalis (De Filipii, 1863)

This non-commercial species is distributed in the Caspian and Azov seas and their basins, including the Volga and Don Rivers ( IUCN, 2024). In the Caspian Sea, it is ubiquitous, with a preference for kelp forests in the Northern Caspian Sea ( Kazancheev 1981; Bogutskaya et al., 2013). The species does not require additional protection due to its stable abundance, widespread distribution and lack of threats to its populations ( IUCN, 2024).