Patterns of genetic diversity: Stepping‐stone dispersal of an invasive fish introduced by an inter‐basin water transfer project

Abstract

Knowledge of large‐scale dispersal processes and their associated genetic diversity patterns is significant for managing invasive species. These patterns remain unclear for invasive species that colonise new habitats through inter‐basin water transfer projects. A worm goby Taenioides cirratus colonised several large inland lakes in China, thereby expanding its distribution through the East Route of the South‐to‐North Water Transfer Project (ESNT). Here, we used nuclear microsatellites to analyse patterns of genetic diversity, population structure, gene flow and, invasion history across its native and invasive ranges in China. Our objectives were to: (a) reveal contemporary genetic diversity patterns of T. cirratus in two native and four invasive populations in China; and (b) identify its main model of dispersal in the ESNT. Invasive populations experienced significant loss of genetic diversity because of bottlenecks and low levels of gene flow, and strong population genetic structure due to founder effects that occurred during expansions. Significant genetic isolation‐by‐distance patterns were largely influenced by landscape connectivity and the reduced active dispersal ability of T. cirratus. The one‐way stepping‐stone dispersal model was identified as being most likely for T. cirratus in the ESNT, influenced by the long distance of upstream dispersal and downstream water transfer events. Our results highlight that T. cirratus could overcome low genetic diversity in founding populations, allowing for invasive spread. For management, we suggest physical removal of invasive populations and installation of deterrents near the pump intake area and the lake outflow to reduce further spread in the system. We provided a general paradigm for understanding dispersal patterns involved in inter‐basin water transfers.

Population structure of Taenioides sp. (Gobiiformes, Gobiidae) reveals their invasion history to inland waters of China based on mitochondrial DNA control region

“…Taenioides sp., which has resided in Taihu Lake for a long period, may have established a relatively stable population capable of maintaining high genetic diversity. T. cirratus, one of the representative invasive species of the genus Taenioides, has invaded Gaoyou Lake, Luoma Lake, Weishan Lake, and Chaohu Lake (Wang et al 2017;Qin et al 2019;Liang et al 2020), also originating from the Yangtze Estuary and Taihu Lake (Qin et al 2022). Similar cases have already been described in several invasive species, such as the Europe-introduced red swamp crayfish Procambarus clarkii (Barbaresi et al 2007) and the Japan-introduced bluegill Lepomis macrochirus (Yonekura et al 2007).…”

“…in Taihu Lake may come from the Yangtze River Estuary (Dai et al 2018). IBD is a common spatial pattern in invasive species (Johansson et al 2018;Qin et al 2022). However, IBD analysis for seven Taenioides sp.…”