Impact of the invasive alien topmouth gudgeon (Pseudorasbora parva) and its associated parasite Sphaerothecum destruens on native fish species

Abstract

The Asian cyprinid Pseudorasbora parva is considered to be a major threat to native fish communities and listed as an invasive alien species of European Union concern. Our study aims to gain evidence-based knowledge on the impact of both P. parva and its parasite Sphaerothecum destruens on native fish populations by analysing fish assemblages and body condition of individuals of native fish species in floodplain water bodies that were invaded and uninvaded by P. parva. We explored the use of environmental DNA (eDNA) techniques to detect S. destruens. Prevalence of S. destruens in native fish species was assessed. Fish samplings showed significantly negative correlations between the abundance of P. parva and the native Leucaspius delineatus, and Pungitius pungitius and three biodiversity indices of the fish assemblages (Simpson's diversity index, Shannon-Wiener index and evenness). Contrastingly, the abundances of the native Gasterosteus aculeatus and P. parva were positively related. In nearly all isolated water bodies with P. parva, this species is outnumbering native fish species. No effect of P. parva presence was found on Electronic supplementary material The online version of this article (

West Asian colonisation of topmouth gudgeon, Pseudorasbora parva (Teleostei: Gobionidae): Genetic admixture at the crossroad of Europe and east Asia

“…High densities of P. parva have severe and significant impacts on native trophic food webs, resulting in overlaps with native fishes trophic niche (Britton et al., 2010). Additional concerns include egg predation, hybridisation with endemic and rare species (Gozlan & Beyer, 2006; Konishi et al., 2003; Simon et al., 2011), facultative parasitism (Gozlan, Andreou, et al, 2010), and transmission of diseases such as the rosette agent Sphaerothecum destruens , which is a novel fungal fish pathogen responsible for the decline of many native fish populations (Andreou & Gozlan, 2016; Combe & Gozlan, 2018; Spikmans et al., 2020).…”

Ethnoichthyology of freshwater fish in Europe: a review of vanishing traditional fisheries and their cultural significance in changing landscapes from the later medieval period with a focus on northern Europe

“…The topmouth gudgeon, originally from Asia and introduced in to the UK in the 1980s for aquaria, soon left these confines and is now found in lakes where it parasitizes other fish eating their scales and flesh. It is now illegal in the UK, but difficult to eradicate and has also been a successful invasive alien elsewhere in Europe [ 176 , 177 ]. A larger fish but a smaller problem in England is wels or the Silurian catfish; a Danubian native, it is now found across western Europe and grows very large, well over 2 m, under the right conditions.…”

Overlapping niches between two co‐occurring invasive fish: the topmouth gudgeon Pseudorasbora parva and the common bleak Alburnus alburnus

“…This species was accidently translocated together with the voluntary spread of Asian carp species for fish farming and consequently spread (Gozlan et al ., 2010). Despite its preference for lotic systems where it generally reaches high abundances, it shows wide environmental adaptability (Britton et al ., 2008; Yan & Chen, 2009), being a carrier for pathogens and parasites (Andreou & Gozlan, 2016; Combe & Gozlan, 2018; Gozlan et al ., 2010; Spikmans et al ., 2020) and competing for food with native fishes (Britton et al ., 2010; Declerck et al ., 2002). The common bleak Alburnus alburnus (Linnaeus 1758) is native to Europe, north of Caucasus, Pyrénées and the Alps, eastward to Ural and Emba, while not being native to southern Europe (Amat‐Trigo et al ., 2019).…”