Comparison of the Growth Dynamics of Invasive Pseudorasbora parva in Three Different Freshwater Systems in Türkiye

Invasive species pose a major threat to aquatic ecosystems worldwide, making it crucial to understand their growth dynamics, dispersal patterns, and biological traits to effectively manage their populations and mitigate associated ecological and economic impacts. Pseudorasbora parva, a small cyprinid fish native to East Asia, has established invasive populations in various inland waters of Türkiye. Specifically, we examined three populations inhabiting Lake Beyşehir (Konya–Isparta), Lake Eğirdir (Isparta), and the Onaç reservoir (Burdur). Monthly sampling was conducted from March 2021 to June 2022 using multimesh gillnets, seine nets, and electrofishing. A total of 1,186 P. parva individuals were sampled from these sites to evaluate growth parameters and assess inter-population differences related to environmental variability. The aim of this study was to determine the growth parameters of P. parva and to evaluate how environmental differences influence population-level growth variability among the three habitats.The three populations studied were observed to differ significantly in terms of age distribution, sex ratio, and growth characteristics. Growth performance was highest in the Lake Beyşehir population, while lowest in the Onaç reservoir population. The Lake Eğirdir population, while growing more slowly, can reach older ages. Length-weight relationships also showed different growth patterns across populations.The results demonstrate a high degree of phenotypic plasticity in P. parva's growth strategies, which are strongly influenced by local habitat conditions. Lake Beyşehir appears to offer the most favourable conditions for its growth, potentially enhancing its invasive impact. The context-dependent growth patterns revealed in this study underscore the necessity for habitat-specific management strategies to control this invasive species and mitigate its threat to native biodiversity, particularly in ecosystems hosting endemic fish species.