Mamilov Nadir Shamilevich, Tursynali Marlen, Khassengaziyeva Gulnur Kuanyshkyzy, Urban Jan, Bartunek Dinara, Sharakhmetov Sayat Ermukhanbetovich, Sapargaliyeva Nazym, Urgenishbayeva Zhansulu, Kegenova Gulnar Bolatovna, Kozhabaeva Eleonora, Baimukanov Mirgaliy, Levin Boris
Department of Biodiversity and Bioresources, Faculty of Biology and Biotechnology, Al-Farabi Kazakh National University, Al-Farabi av., 71, Almaty 050040, Kazakhstan.
Laboratory of Signal and Image Processing, Institute of Complex Systems, Faculty of Fisheries and Protection of Waters, CENAKVA, University of South Bohemia in Ceske Budejovice, Zámek 136, 373 33 Nové Hrady, Czech Republic.
Animals (Basel). 2024 Oct 18;14(20):3013. doi: 10.3390/ani14203013.
Rainbow trout, or mykiss (), is one of the most popular species used in aquaculture and has been naturalized worldwide, including in the Central Asian Balkhash basin, which has unique aboriginal fish fauna. Both rainbow trout from European farms and wild mykiss from Kamchatka were introduced to some mountain lakes and rivers of the Balkhash basin about 50 years ago. This study investigates the current distribution and life history traits of the alien species and its possible impact on the local fish fauna. This study showed that the rainbow trout occupies various habitats in the Ili River basin: mountain lakes, fast-flowing mountain rivers, and lowland rivers with slow currents and warm water (up to +27 °C). Rainbow trout from European fish farms dominate the mountain Middle Kolsay Lake, while the wild trout from Kamchatka occupies the small Ulken Kokpak River. Both co-occur in the Chilik River. Contrary to that in other regions, the distribution of rainbow trout in the Balkhash basin remained almost the same after their introduction. Broad intrapopulation variability in terms of size, growth rate, and maturation age was revealed, apparently as a result of adaptation to the new environment and intrapopulation competition. In particular, the growth rate has decreased, but life span, surprisingly, has increased as compared to the originally introduced fish. Intrapopulation variation in growth and maturity patterns was also noted. Differences in skin coloration between highland (cold-water) and lowland (warm-water) populations were discovered. The feeding mode of naturalized trout is insectivorous (insect imago), indicating that it occupies its own niche in the local fish communities. The largest population of rainbow trout was recorded in the Lower Kolsay Lake, lowering the population of native fish species, while in other localities, no negative impact on local fish communities was recorded.
虹鳟，即硬头鳟（Oncorhynchus mykiss），是水产养殖中最受欢迎的物种之一，已在全球范围内归化，包括在拥有独特原生鱼类区系的中亚巴尔喀什湖流域。大约50年前，来自欧洲养殖场的虹鳟和来自堪察加半岛的野生硬头鳟被引入了巴尔喀什湖流域的一些山区湖泊和河流。本研究调查了外来物种的当前分布和生活史特征及其对当地鱼类区系可能产生的影响。研究表明，虹鳟在伊犁河流域占据了各种栖息地：山区湖泊、湍急的山区河流以及水流缓慢且水温较高（高达27摄氏度）的低地河流。来自欧洲养鱼场的虹鳟在山区的中科尔赛湖占主导地位，而来自堪察加半岛的野生鳟鱼则占据了小乌尔肯科帕克河。两者在奇利克河共同出现。与其他地区不同的是，虹鳟在巴尔喀什湖流域引入后其分布几乎保持不变。研究揭示了在体型、生长速度和成熟年龄方面存在广泛的种群内变异性，这显然是适应新环境和种群内竞争的结果。特别是，生长速度有所下降，但令人惊讶的是，与最初引入的鱼类相比，寿命却有所延长。还注意到生长和成熟模式的种群内差异。发现高地（冷水）和低地（温水）种群之间的皮肤颜色存在差异。归化鳟鱼的摄食方式为食虫性（昆虫成虫），这表明它在当地鱼类群落中占据了自己的生态位。在下科尔赛湖记录到了最大数量的虹鳟，当地原生鱼类种群数量因此减少，而在其他地区，未记录到对当地鱼类群落的负面影响。
