Interpopulation Variability in Dietary Traits of Invasive Bleak Alburnus alburnus (Actinopterygii, Cyprinidae) Across the Iberian Peninsula

Abstract

The bleak Alburnus alburnus is native to most of Europe. This cyprinid fish is a successful invader in the Iberian Peninsula. No studies exist on its foraging strategies on a large scale for this ecoregion. The aim of the present study was to compare dietary traits of invasive bleak among the main Iberian rivers and a ‘reference’ native bleak population from France. Bleak were sampled during May–June 2019 from the Iberian Rivers Ebro, Tagus, Guadiana, Segura and Guadalquivir and the River Saône (France). Diptera larvae and zooplankton were common food categories in the River Saône. Insect nymphs were more important in the River Ebro. The intake of plant material was higher in the River Tagus. Flying insects were more consumed in the River Guadiana. Nektonic insects were important in the River Guadalquivir. Detritus was a frequent food category for all populations, in terms of occurrence and mass. Dietary parameters followed a unimodal response in relation to the latitudinal gradient, with the maximum values for the Tagus and Guadiana populations. Overall, results suggest that this wide inter-population variability will contribute to the species’ successful establishment throughout Mediterranean Europe, which poses a serious risk to its highly valuable native fish fauna.

Comparing morphological, parasitological, and genetic traits of an invasive minnow between intermittent and perennial stream reaches

“…Specifically for the Iberian Peninsula, which mostly has a Mediterranean climate, invasive Cypriniformes fishes from the rest of Europe, which mostly has a Temperate climate, usually display high variability under contrasting environmental conditions. This contributes to enhance the invasion process throughout this eco‐region of high richness, in terms of fish biodiversity (Latorre et al, 2018, 2020; Ribeiro & Veríssimo, 2014). Accordingly, the examined biological traits were clearly variable within the study population, which is surely linked to particular fluvial conditions (i.e.…”

“…Immediately after euthanasia, fish were measured for SL (±1 mm). As per Latorre et al (2020), this particular fish length was selected because it avoids potential noise given by variation of caudal fin length not related to body size (e.g. wounds and cuts in the fish skin and rays).…”

“…This information would enable us to characterise the specific features of successful invaders in the Iberian Peninsula (García-Berthou, 2007;Ribeiro et al, 2008). Thus, environmental managers could use such data to identify new vulnerable areas for fish invasion, in order to avoid the expansion across Iberian fresh waters (Almeida, Ribeiro, et al, 2013;Latorre et al, 2018Latorre et al, , 2020.…”

“…Growing concern about the impacts of non‐native fishes has led to research on these species within their introduced ranges under the particular environmental conditions of those areas, where they may confront new ecological stressors, such as floods, droughts, fluctuating food supply, or native predators (Almeida et al, 2014; Latorre et al, 2020). Nevertheless, there is still an urgent need to improve our knowledge on the invasion process of non‐native fishes, particularly the key biological traits that increase colonisation capacity throughout novel habitats (Brandner et al, 2013; Rubenson & Olden, 2017).…”

Ecology and Conservation of Freshwater Fishes Biodiversity: We Need More Knowledge to Develop Conservation Strategies

“…Both studies are focused on the significant role of plasticity in the success of these invasive alien species. Latorre et al [14] assess the variability in dietary traits of the bleak in the Iberian Peninsula and compare the dietary characteristics of this species among the main Iberian rivers and a native bleak population from France. Similarly, Amat-Trigo et al [15] evaluate other biological traits in addition to the diet.…”