Inter-population variability in growth and reproduction of invasive bleak Alburnus alburnus (Linnaeus, 1758) across the Iberian Peninsula

Abstract

The native European freshwater cyprinid fish, common bleak Alburnus alburnus (Linnaeus, 1758), is an invasive non-native fish in the Iberian Peninsula, where it threatens the valuable endemic fish fauna. Despite the bleak’s invasive status, there is a dearth of studies on the biological traits of non-native populations in Europe’s Mediterranean region, and the present study aimed to compare bleak growth and reproductive traits across the principal rivers of Iberia with those from a native ‘reference’ bleak population in France. Non-native bleak from the River Tagus had the highest back-calculated total lengths (TLs), growth rate and body condition, but the lowest reproductive investment and smallest egg size of all studied populations. Whereas, these latter two traits were the highest in the River Ebro, where fecundity was the lowest for all Iberian rivers. The youngest age and the smallest TL at maturity were observed in the River Ebro. The River Segura had the lowest back-calculated TLs and growth rate, the highest fecundity and proportion of females, and the oldest age at maturity. Population traits of bleak in the River Saône (the native ‘reference’ population) were generally different from those in Iberian rivers, except for the River Ebro. This wide inter-population variability contributes to the species’ successful establishment in novel habitats.

Biology and ecology of the accidentally introduced bleak, Alburnus alburnus (Actinopterygii: Cypriniformes: Cyprinidae), in Keddara Dam Lake, Algeria

“…By contrast, we have noticed a faster growth compared to Greece (Politou unpublished * ). Moreover, in the Iberian Peninsula , Latorre et al 2018) and in the Danube River in Serbia (Lujić et al 2013), the growth rates were lower than those obtained in Keddara Dam Lake.…”

“…This variation was due to the geographic location and environmental conditions such as temperature, salinity, pH, dissolved oxygen, Secchi disk visibility depth, and the water system (Ongun-Sevindik et al 2010, Çelik 2013. Also, the highest condition factor values were obtained in the Iberian Peninsula (Latorre et al 2018), the Danube in Serbia (Lujić et al 2013), and Pilica in Poland (Mann and Penczak 1984). The differences in those values are due to the variation in latitude and ecosystem type (Latorre et al 2018).…”

“…Also, the highest condition factor values were obtained in the Iberian Peninsula (Latorre et al 2018), the Danube in Serbia (Lujić et al 2013), and Pilica in Poland (Mann and Penczak 1984). The differences in those values are due to the variation in latitude and ecosystem type (Latorre et al 2018).…”

“…This numeric dominance was attributed, according to and Zaugg (unpublished ** ), to the rapid growth and early maturity of the females and higher mortality of the males. However, in the Iberian Peninsula , Latorre et al 2018) and in the Danube River in Serbia (Lujić et al 2013), the entire bleak population was dominated by males. According to these authors, this was due to the period of sampling and the behaviour of the males, especially in the period of spawning, which significantly increases their probability of capture.…”

“…It is an invertivorous, phyto-lithophylous, reolimnic, and limnophilic species (Adamczyk et al 2017). This small sized fish was repeatedly, accidentally introduced in waters of the Iberian Peninsula (Vinyoles et al 2007, Latorre et al 2018, Sousa-Santos et al 2018. Its first accidental introduction in Algeria (North Africa), with carps imported from Hungary, took place at the reservoir of Hamiz in 2006.…”