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For the first time the presence of gibel carp Carassius gibelio has been detected in the brackish meromictic Lake Shira (Southern Siberia, Republic of Khakassia). Lake Shira has been continuously studied since the late 19th century, and it has been considered so far that there is no ichthyofauna in the lake. This work investigates the growth and population characteristics, as well as food spectra and fatty acid composition of C. gibelio specimen at different ages that were fished out in the summers of 2007 and 2008. The water salinity at the fishing point was 15 g l-1. The food spectrum of one- and two-year old C. gibelio was dominated by diatomic, green and blue-green algae, while four- to sixyear old species had an increased share of copepods, beetles and chironomids in their food spectrum, and beginning from the age of six years the amphipods Gammarus lacustris consisted significant part of gibel carp diet. Thus, it was shown that C. gibelio is a carnivore with regard to the population of amphipods Gammarus lacustris, which have been regarded so far as the upper link in the trophic cascade of Lake Shira. One of the possible reasons for appearance of fish is the decreased water salinity caused by rising of the lake level. In the recent years, the level of Lake Shira exceeded all the values that had been registered since the late 19th century, and the lakes salinity decreased correspondingly to its smallest value for the whole period of observation. В солоноватом меромиктическом оз. Шира (Южная Сибирь, Республика Хакасия) зарегистрировано присутствие серебряного карася Carassius gibelio. Озеро Шира непрерывно изучается с конца XIX в., и до сих пор считалось, что ихтиофауна в данном озере отсутствует. В настоящей работе исследуются морфологические характеристики, спектр питания и жирнокислотный состав особей Carassius gibelio различного возраста, выловленных в оз. Шира в летнее время 2007 и 2008 гг. Соленость воды в местах вылова была около 15 г/л. Среди пищевых компонентов особей возраста 1-2 лет преобладали диатомовые, зеленые и сине-зеленые водоросли. У особей от четырех до семи лет в пище увеличивалась доля копепод, жуков и хирономид. Начиная с шестилетнего возраста значительную долю в рационе составляли бокоплавы Gammarus lacustris. Таким образом, серебряный карась может быть хищником по отношению к популяции Gammarus lacustris, который до сих пор считался верхним звеном трофического каскада в экосистемы оз. Шира. Одна из возможных причин появления карася в озере - снижение солености, обусловленное повышением уровня озера. В последнее десятилетие уровень оз. Шира превысил все значения, известные для данного озера с конца XIX в. Соответственно, соленость воды в озере снизилась до минимального значения из всех зарегистрированных ранее.

A necessary condition for investigating microbial communities in chemocline zones of stratified waterbodies is high-precision sampling at a depth resolution of several centimeters. We have modified a multi-syringe sampler that is conventionally used by researchers for this purpose. The main distinctive feature of our sampler is that plungers are operated hydraulically rather than pneumatically and, thus, our sampler has the following advantages: (1) the plungers cannot move spontaneously, which ensures sampling adequacy, especially in deep-water sampling; (2) filling of the syringes with the sample can be monitored from a distance; (3) during storage, the internal volume of the syringe and the whole hydraulic system is aseptic (if 70% ethanol is used as a working fluid), which is important if samples are to be used for microbiological tests. (4) the problem of sticking plungers is minimized, even after extended storage. Vertical sampling of the chemocline zones of meromictic lakes in Southern Siberia (Russia, Khakasia) at a depth resolution of 5 cm proves that the sampler is very reliable and simple to use.