Production and parasitological characteristics of invasive short-cycle fish species in water bodies on the eastern slope of the Southern Urals

Abstract

In the course of planned or accidental fish intro� duction, rapid dispersal and range expansion are char� acteristic primarily of shortcycle species, i.e., small, early maturing fishes with partial spawning. A special place in the problem of population outbreaks and invasions belongs to the role of invasive species in the trophic structure of new biocenoses and also their role as carriers of some symbionts and parasites (Dge� baudze, 2002). The most prevalent invasive fish species in water bodies of the southern Transural region are the Amur sleeper ( Percottus glehni Dybowski, 1877), which appeared in waters of the region due to negligence of aquarists (Dubchak and Magazov, 2004) and widely dispersed in the 1980s, and the sunbleak (Leucaspius delineatus Heckel, 1843), which was brought in as eggs together with common carp spawners in the 1960 and has also dispersed widely since then (Korlyakov, 2008). The European smelt (Osmerus eperlanus Linnaeus, 1758), introduced into Bol'shoi Kisegach Lake in the 1930s, has successfully acclimated in this deep, cold� water biotope (Korlyakov and Kolenova, 2005). In the upper Tobol River basin, some river biotopes are pop� ulated by the common bleak (Alburnus alburnus Lin� naeus, 1758), which was brought in due to fishstock� ing activities in the 1970s (Andreyashkin and Dobrin� skaya, 1988; Korlyakov, 2008). These four species, which naturally reproduce in the region, represent dif� ferent faunal complexes according to Nikol'skii's (1953) classification: the Amur sleeper came from the Amur River basin; the natural range of the common bleak and sunbleak is in the Volga basin; and the Euro� pean smelt, which lives in rivers of northern Europe, represents the arctic faunal complex.