The role of abiotic and biotic factors in interspecific competition of Polish crayfish – comprehensive literature review

Invasive species are those that have been transferred by humans out of their natural range. Native crayfish species in Polish waters include: Astacus astacus and Pontastacus leptodactylus, whereas invasive species are: Pacifastacus leniusculus, Faxonius limosus, Procambarus clarkii and Procambarus virginalis. The objective of this study was to determine how abiotic and biotic environmental factors contribute to interspecific competition of Polish crayfish based on the available literature. Abiotic factors affecting the interspecific competition include tolerance to extreme pH values, calcium ion content, temperature, oxygenation, water salinity, preferred substrate and the type of water bodies. Biotic factors are, inter alia, pathogens, food base, plant cover and interactions in the prey–predator system, as well as interactions between crayfish species. The most important abiotic factors are water temperature and oxygenation, while the most important biotic factor is the crayfish plague – a deadly disease for native species. Each invasive species has a different set of traits and adaptations that enable a successful invasion. However, a successful invasion of a given species is not determined by one, but many adaptations that coexist.