Alien fish species in the Ob River basin.

To date, 22 alien fish species are known in the Ob River basin. Of them, nine species-Pike-perch Sander lucioperca, Freshwater bream Abramis brama, common carp Cyprinus carpio, belica Leucaspius delineatus, bleak Alburnus alburnus, Stone moroko Pseudorasbora parva, Amur sleeper Perccottus glenii, Nikolsky's loach Misgurnus nikolskyi, and southern ninespine stickleback Pungitius platygaster-formed self-reproducing populations and started self-spreading in natural waterbodies. This paper summarizes the data on invasion of alien fish species in the Ob River basin. The data on history, rate of spread, modern distribution, and relative abundance are given. It is shown that water temperature is the main environmental factor which limits the expansion of introduced species in the Ob basin. [ABSTRACT FROM AUTHOR]