Stenodus leucichthys is a species of freshwater whitefish in the family Salmonidae. In the strict sense its natural distribution is restricted to the Caspian Sea basin. It is now considered extinct in the wild, but survives in cultured stocks. The nelma, a more widespread species of Eurasian and North America, is sometimes considered its subspecies.
Arctic cisco, also known as omul, is an anadromous species of freshwater whitefish that inhabits the Arctic parts of Siberia, Alaska and Canada. It has a close freshwater relative in several lakes of Ireland, known as the pollan, alternatively regarded as conspecific with it, or as a distinct species.
The broad whitefish is a freshwater whitefish species. Dark silvery in colour, and like a herring in its shape. Its distinctive features includes: a convex head, short gill rakers, and a mild overbite. It is found in the Arctic-draining streams, lakes, and rivers of far eastern Russia and North America. Its prey includes larval insects, snails, and shellfish. It is eaten by humans and brown bears.
Stenodus is a genus of large-sized whitefish in the family Salmonidae. It consists of two species; one of them (beloribitsa) is extinct in wild. The two species have alternatively been considered subspecies of the single species Stenodus leucichthys.
The Albanian barbel is a ray-finned fish species in the family Cyprinidae. It is often referred to as "Albanian barbel" in a literal translation of its scientific name.
The Danube bleak or Caspian shemaya is a species of freshwater fish in the family Cyprinidae. It is found in Iran, Ukraine, Georgia, Armenia, Slovakia, Moldova, Greece, Czechia, Azerbaijan, Turkiye, Afghanistan, Austria, Bosnia and Herzegovina, Bulgaria, Croatia, Switzerland, Germany, Hungary, Italy, Romania, Russia, Serbia, Slovenia, Turkmenistan, and Uzbekistan.
Rutilus frisii, called the vyrezub, Black Sea roach, or kutum, is a species of fish in the family Cyprinidae, native to the basins of the Black Sea, Sea of Azov, and Sea of Marmara from the rivers of Bulgaria to western Transcaucasia and in Lake Iznik (Turkey).
Abrau sprat, Clupeonella abrau, is a species of freshwater fish in the family Clupeidae. It is found landlocked in Russia in a single locality, Lake Abrau, located at 70 m above sea level near the Black Sea coast close to Novorossiysk. The lake is small and has been stocked by several alien species, whence the Abrau sprat is considered critically endangered.
The humpback whitefish, also referred to as the bottom whitefish, the Arctic whitefish or the pidschian, is a species of freshwater whitefish with a northern distribution. It is one of the members in the broader common whitefish complex, or the Coregonus clupeaformis complex. This fish lives in estuaries and brackish water near river mouths, in deltas and in slowly running rivers, in large lakes with tributaries, and floodplain lakes. It can migrate long distances upriver for spawning.
The Donets ruffe is a species of perch native to eastern Europe where it occurs in the basins of the Black Sea and the Sea of Azov. They inhabit freshwater lakes and rivers usually over hard compacted sand. They are predominantly crepuscular and prey mostly on invertebrates, rarely on fish. They are inactive during winter months, and usually move to deeper places until the ice melts. Spawning occurs in small rivers with heavy currents. This species reaches a length of 21 centimetres (8.3 in) SL.
The Volga undermouth or Volga nase is a species of cyprinid freshwater fish. This one lives in the Emba, Ural, and Volga drainages of the Caspian Sea basin and the Don River drainage of the Black Sea basin.
Coregonus maraena, referred to in English as the maraene, maraena whitefish, vendace, cisco, lake herring, lake whitefish or the whitefish, is a whitefish of the family Salmonidae that occurs in the Baltic Sea basin - in the sea itself and the inflowing rivers, and in several lakes as landlocked populations. It is found in Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Netherlands, Norway, Poland, Slovakia, Russia and Sweden. As of 2013, it has been listed as a vulnerable species by the IUCN and as endangered by HELCOM. It is an extremely important fish within the Baltic Sea ecosystem, both for population equilibrium and for the local diets of the surrounding human population. Due to a variety of factors, mostly overfishing, the maraena's population dwindled to near-extinction levels. Thus, rampant repopulation was enacted to preserve this important fish.
The eastern tubenose goby is a species of gobiid fish native to fresh and brackish waters of the basins of the Sea of Azov and the Caspian Sea and has invaded the upper reaches of the Volga River from its native occurrence in the delta. This species prefers slow flowing rivers or still waters with plentiful rocks or vegetation. It can reach a length of 9 centimetres (3.5 in) SL. It is probably the same species as that recently treated as Proterorhinus semipellucidus.
Ponticola gorlap, or the Caspian bighead goby, is a species of goby, a benthic fish native to the Caspian Sea basin. It is widespread in lower parts of many rivers in Iran, and also found in Azerbaijan and Turkmenistan. In Russia, it occurred in the lowest part of the Volga up to Astrakhan until 1977, but has thereafter spread upstream. In 2000 it was recorded as being established in the Ivankovo and Rybinsk Reservoirs in the Moscow region, and already invaded the Don drainage by way of the Volga–Don Canal in 1972. This species occurs in sheltered environments, such as inshore fresh or brackish waters of estuaries, lagoons, lakes and large rivers, where it prefers habitats with a well vegetated rock or firmly packed sand substrate. It can reach a length of 20 centimetres (7.9 in) SL, and a common size is 12 centimetres (4.7 in) SL.
The Don tadpole-goby is a species of goby widespread in the basin of the Sea of Azov, specifically in the lower Don River and Tsimlyansk Reservoir. This species is found in rivers, reservoirs and river mouths, but is not known to enter seas. It is introduced and invasive upstream the Volga River, e.g. the Kuibyshev Reservoir. This fish can reach a length of 6.6 centimetres (2.6 in) SL. Life span is about one year.
The cactus roach is a species of fish in the family Cyprinidae, native to the basin of the Danube River upstream of the Iron Gate, very numerous in the Sava basin. It is also recorded in the Ukrainian Zakarpattian region. This freshwater fish is up to 55 cm long.
White-eye bream is a fish species of the family Cyprinidae. It is widespread in many large rivers in Europe and Asia in drainages of the Black Sea, Caspian Sea, and Aral Sea. It was introduced to several rivers in northern Russia, the Rhine, and the Vistula drainage system where it is invasive, coming from the Black Sea basin through the Dnieper–Bug Canal. Freshwater fish are up to 35 cm long.
The Caspian gudgeon is a freshwater fish species in the family Cyprinidae. It is a small fish, less than 10 cm, which is distributed in the drainages of the Western Caspian Sea basin in Russia and adjacent countries. It is widespread and not threatened, but there is no information about its biology.
The northern whitefin gudgeon is a species of freshwater fish in the family Cyprinidae. It is distributed in the northern Black Sea basin, southern Baltic Sea basin, southern North Sea basin. Also, reports from lakes Ilmen and Ladoga and its basins have been made, which are questionable. Their maximal length is 11.5 cm, with a maximal reported age of 5 years.
Cottus metae is a species of freshwater ray-finned fish belonging to the family Cottidae, the typical sculpins. It inhabits the upper Save River system in the Danube basin. It reaches a maximum length of 9.7 cm. It prefers small streams to medium-sized rivers. This species was described as a separate species from the European bullhead in 2005 by Jörg Freyhof, Maurice Kottelat and Arne W. Nolte. The specific name 'honours the Slovenian biologist Meta Povž, in recognition of her assistance to the authors in a variety of projects.
