1. RETROSPECTIVE ANALYSES OF ALIEN AND INVASIVE FISH SPECIES INTRODUCTION IN THE ARAL SEA DRAINAGE BASIN ON EXAMPLE OF THE REPUBLIC OF UZBEKISTAN, CENTRAL ASIA Karimov B.K*., Yuldashev M.A., Kamilov B.G. Institute of Gene Pool of Plants and Animals World (IGPPAW) of Uzbekistan Academy of Sciences, 232 Bagishamal Street, Tashkent 100125 Uzbekistan (karimov@sarkor.uz) Study Site  The Aral Sea basin (ASB) is situated within Central Asia and covers an area of 2.2 million km2 and is home to around 50 million people. It comprises the drainage area of two major rivers, the Amudarya and the Syrdarya and the Aral Sea itself. Eastern part of the basin is covered by massive high mountains; central and western part s plain covered by steppes and deserts;  Waterbodies of Uzbekistan are part of the deeply landlocked Aral Sea drainage basin (ASDB).  Arid and desert climate: 100-200 mm/a precipitation in the plains.  Huge expansion of irrigated agriculture for cotton production.  Salinity of water in Large Aral Sea rose from 10 before 1960s to more than 130 g/L. Introduction  The list of fishes of the Republic of Uzbekistan in natural conditions (until 1950-s) according to different estimations included 44-49 species. In the 20th century the ichthyo-fauna was intensively influenced by various anthropogenic factors: the introduction of alien and invasive species and starting from 1950s transformation of hydrographical and hydrological regimes of aquatic ecosystems caused by the development of irrigation. There are more than 15 large brackish water lakes (3-12 g/L) with 9000 km² of total water surface area fed by drainage waters in Uzbekistan.  Introduction of alien species by human is an exclusive invasive corridor into this landlocked closed basin. During Soviet times all introductions were accompanied by long term research monitoring and few aspects of alien species biology under new habitat conditions and there relationships with local fish species were studied. However, during the last years data on fish introductions were very limited.  Goal of this work was summarizing, systematization and retrospective analyses of alien and invasive fish species introductions into water bodies of Aral Sea Basin on example of the republic of Uzbekistan. With a few exceptions the findings of this study can be applied also for neighboring countries : Kazakhstan, Kyrgyzstan, Tajikistan and Turkmenistan. Results Threats for new fish species introduction:  Diminishing water flow volumes during low water years and droughts  Unfavorable hydrochemistry and water quality due to use of banned pesticides, salinization, pollution with heavy metals, etc.  Absence of fish protection constructions in water intakes, poaching and illegal fishing. Retrospective analyses of invasive fish species introduction  The introduction of invasive species was commenced with introduction of the mosquito fish in 1920s for health care purposes to control malaria. All fish introductions were aimed for fisheries (except the mosquito fish) and may be grouped into 3 types:  a) to the Aral Sea for improving of commercial species structure and to mitigate increasing salinities (early 1980s all 20 native Aral species were disppeared);  b) to newly created irrigational water bodies for commercial fish stocks formation and increase of fish productivity;  c) to aquaculture for fish policulture development and to use plant food resources of pond ecosystems. The present study was supported by State Grants of the Republic of Uzbekistan Conclusions  In general, 47 fish species were introduced, of which 23 were intentional and 24 accidental. Donor waterbodies were: the Caspian Sea (8), the Black Sea (1), the Baltic Sea (1), waterbodies of the Caucasus (2), the European part of Russia (8), lakes of Kyrgyzstan (4), fish ponds of Kazakhstan (3) and rivers of the Far East (20).  From the European part of Russia 7 species of north-American ichthyofauna and 1 Far East specimen were introduced. The mosquito fish was brought from the Caucasus.  Three species of Siberian whitefishes (Coregonidae) and the sevan trout which in Lake Issyk-Kul has formed a special form – gegarkuni were brought from Kyrgyzstan.  Ten species were introduced to the Aral Sea, 4, water reservoirs; 31, to fish ponds.  The secondary resettlement was observed for 27 species and 20 species could not resettle within the (ASB).  In new natural conditions 31 species could reproduce and 16 species could not.  At present 22 introduced species have disappeared, 7 species are rear and 18 species become fully naturalized and even abundant.  The commercial structure of introduced species was the following: 6 valuable, 18 commercial and 23 low-commercial and trash species. No SpeciesEnglish name Years of Introduc- tion # Intentional/ Accidental Waterbody - recipient Secondary spread Reproduc- tion Quantity in new water bodies Quantity of populations Region - donor 1 Acipenser stellatusStellate (starred) sturgeon1920,1940intentionalAral SeanoyesNo Caspian Sea 2 Abbotina rivularisAmur false gudgeon1960AccidentalaquacultureYesyesCommonfewFar East 3 Acipenser baieriiSiberian sturgeon1980intentionalaquacultureno NooneRussia ## 4 Alosa caspia caspiaCaspian shad1920intentionalAral Seano NonoCaspian Sea 5 Atherina mochon ponticaSilverside1950AccidentalAral SeaYesyesVery rareNo data###Caspian Sea 6 Carassius gibelioSilver prussian carp1960intentionalaquacultureYesyesCommonfewRussia 7 Channa argus warpachowskiiAmur snakehead1960intentionalaquacultureYesyesCommonfewRussia 8 Clupea harengus membrasBaltic herring1950intentionalAral Seano No Baltic Sea 9 Coregonus lavaretus ludogaLudoga1980AccidentalreservoirnoyesRareOne Kyrgyzstan 10 Coregonus peledPeled1980intentionalreservoirnoyesRareOneKyrgyzstan 11 Coregonus sardinellaSardina cisco1980AccidentalreservoirnoyesRareOneKyrgyzstan 12 Ctenopharyngodon idellaGrass carp1960intentionalaquacultureYesyesCommonfewFar East 13 Diplophysa labiata (=barbatula labiata)Plain stone loach1950Accidentalaquacultureno RareOne Kazakhstan 14 Elopichthys bambusaYellowcheek1960Accidentalaquacultureno No Far East 15 Gambusia affinisGambusia1930intentionalDifferentYesyesCommonfewCaucas 16 Gambusia holbrookiGambusia1930intentionaldifferentYesyesCommonfewCaucas 17 Hemibarbus maculatesSpotted steed1960Accidentalaquacultureno No Far East 18 Hemiculter leucisculusSharpbelly1960AccidentalaquacultureYesyesCommonfewFar East 19 Hemiculter lucidusUssuri sharpbelly1960AccidentalaquacultureYesyesRareNo dataFar East 20 Hypophthalmichthys molitrixSilver carp1960intentionalaquacultureYesyesCommonfewFar East 21 Hypophthalmichthys nobilisBighead carp1960intentionalaquacultureYesyesCommonfewFar East 22 Ictalurus punctatusChannel catfish1970intentionalaquacultureYesnoNo Russia 23 Ictiobus bubalusSmallmouth buffalo1970intentionalaquacultureYesnoNo Russia 24 Ictiobus cyprinellusBigmouth buffalo1970intentionalaquacultureYesnoNo Russia 25 Ictiobus nigerBlack buffalo1970intentionalaquacultureYesnoNo Russia 26 Knipowitschia caucasicaCaucasian dwarf goby1950AccidentalAral SeanoyesNo Caspian Sea 27 Megalobrama terminalisBlack amur bream1960Accidentalaquacultureno No Far East 28 Micropercops swinhonisMicropercops1960AccidentalaquacultureYesyesCommonfewFar East 29 Mugil auratusGray mullet1950intentionalAral Seano No Caspian Sea 30 Mylopharyngodon piceusBlack carp1960AccidentalaquacultureYesyesRareOneFar East 31 Neogobius fluviatilisMonkey goby1950AccidentalAral SeanoyesnoNoCaspian Sea 32 Neogobius melanostomusCaspian round goby1950AccidentalAral SeanoyesNo Caspian Sea 33 Oncorhynchus mykissRainbow trout1970intentionalaquacultureYesyesCommonДваRussia 34 Opsariichthys uncirostrisAmur three-lips1960AccidentalaquacultureYesyesCommonfewFar East 35 Oryzias latipes sinensisMedaka1990AccidentalaquacultureYesyesCommonfewKazakhstan 36 Parabramis pekinensisWhite amur bream1980AccidentalaquacultureYesyesRareoneFar East 37 Perca schrenkiiBalkhash perch1950AccidentalaquacultureYesyesCommonOneKazakhstan 38Percottus glehni Chinese sleeper1960Accidentalaquacultureno No Far East 39 Platichthys flesus luscusEuropean flounder1970intentionalAral SeanoyesRareoneBlack Sea 40 Proterorhinus marmoratusTube-nosed goby1950AccidentalAral SeanoyesNo Caspian Sea 41 Pseudorasbora parvaStone morokos1960AccidentalaquacultureYesyesCommonfewFar East 42 Rhinogobius similisAmur goby1960AccidentalaquacultureYesyesCommonfewFar East 43 Rhodeus ocellatus ocellatusRosy bitterling1960AccidentalaquacultureYesyesCommonfewFar East 44 Salmo ischanSevan trout1970intentionalreservoirnoyesRareoneKyrgyzstan 45 Siniperca chuatsiChinese perch1960Accidentalaquacultureno NonoFar East 46 Tinca tincatench1950intentionalaquacultureno NonoKazakhstan 47 Triplophysa strauchii strauchiiSpotted stone loach1950Accidentalaquacultureyes commonfewKazakhstan # - data are given for decades (for example – 1950s, 1960s, etc.); ## - fish farms of European part of Russia; Abundant in Small Aral, Kazakhstan The list of introduced alien and invasive fish species and the results of their introduction in Uzbekistan during the XX – XXI centuries It is noteworthy that in all cases of naturalization the new species were stocked in artificial waterbodies with unstable local fish fauna, e.g. fish ponds, water reservoirs and lakes of irrigational origin. Numbers of invasive species were naturalized in one waterbody, however, they were not resettled to other ones because of hydrographic or ecologic barriers (e.g. whitefish and trout in Charvak reservoir and spotted stone loach around fish farm “Damachi”). Numbers of species of Chinese complex had advantages in reproduction comparing to local fishes: taking care of offspring, early maturation, portioned spawning, high fecundity (snakehead, three-lips, stone morokos, bitterling, amur gobi, sawbelly, ruff (pope). In native habitats these species were exposed stronger predator stress. They won competition with local species such as Zarafshan dace, gudgeon and Tashkent verkhovodka, which disappeared from the mid-reach of the Syrdarya River. The range of habitat of other species, such as the Syrdarya dace, the Golden spiny loach, the striped bystryanka and the Kuschakewitch stone loach has significantly dwindled and they remained only in foothill water courses and waterbodies.