Biological features of ninespine stickleback Pungitius pungitius (Linnaeus, 1758) of the local population of the Ushakovka River

Abstract

At present in the ichthyofauna of the Cheboksary Reservoir and its basin, there are 21 invasive species. One of the naturalized species is the ninespine stickleback Pungitius pungitius (Linnaeus, 1758), which formed a local population in the Ushakovka River. The biology of P. pungitius in the Cheboksary Reservoir basin has not been described yet. The present article reports biological features of the population of P. pungitius in the Ushakovka River observed since 2003. During this period there were significant changes in distribution and abundance of P. pungitius and in some of its morphological characteristics. Particularly interesting is the adaptation of P. pungitius to new environmental conditions and its survival during the anomalously long drought period in summer 2010. In general, P. pungitius successfully naturalized in the Ushakovka River, but the stability of development of its population is exposed to environmental factors: changes in hydrological conditions due to construction of artificial barriers, changes in hydrochemical conditions due to runoff from the asphalt plant, and desiccation of some parts of the river in low-level and dry years. These circumstances resulted in formation of special biological traits in the population of P. pungitius in the Ushakovka River.