Freshwater crayfish in Serbia: Update on the distribution

Abstract

Our study aims to build upon a prior studies of crayfish distribution by consolidating findings from our fifteen years field research and summarizing existing published data. In Serbian freshwater ecosystems, we have identified the stone crayfish Austropotamobius torrentium, the noble crayfish Astacus astacus, and the narrow-clawed crayfish Pontastacus leptodactylus as native species. Unfortunately, our ecosystems have been penetrated by two invasive species: the spiny-cheek crayfish Faxonius limosus, first discovered in 2004, and the signal crayfish Pacifastacus leniusculus, more recently found in 2020. Fifteen years since the last research, we have observed that the most commonly found native crayfish is the stone crayfish, documented at 206 sites in 131 freshwater ecosystems, followed by the noble crayfish (46 sites in 31 freshwater ecosystems) and the narrow-clawed crayfish (22 sites in 11 freshwater ecosystems). Field observations have shown that changes in habitat and the increasing impact of climate change (significant droughts and floods over the past decade), primarily affect native crayfish populations. Understanding species distribution is fundamental to a wide range of biological research. Gathering additional data on species distribution is essential for enhancing our understanding of biodiversity, the functioning of aquatic ecosystems, conservation planning, climate change adaptation, and the management of invasive species. Moreover, distribution data is crucial for monitoring endangered species, such as the stone and noble crayfish, which are strictly protected under the Rulebook on the Proclamation and Protection of Strictly Protected and Protected Wild Species of Plants, Animals, and Mushrooms ("Official Gazette of RS" no. 5/2010, 47/2011, 32/2016 and 98/2016).