SUMMARY
There was described a new species for fish fauna of Western Podolian Prydnistrovya – stickleback Gasterosteus aculeatus Linnaeus, 1758 (Gasterosteidae). The changes of plastic and meristic characters, diet and propagation in comparison with other water bodies of Ukraine were studied. It was shown that present conditions of nonmigratory form of stickleback in waters of the region are favourable. There was made a conclusion on high possibility of further increase of the stickleback number and enlargement of its distribution range.