Invasions have increased the size of regional species pools, but are typically assumed to reduce native diversity. However, global‐scale tests of this assumption have been elusive because of the focus on exotic species richness, rather than relative abundance. This is problematic because low invader richness can indicate invasion resistance by the native community or, alternatively, dominance by a single exotic species. Here,...

The hypothesis that effective population sizes are low in hatchery‐reared catla ( Catla catla ) from Bangladesh, possibly leading to inbreeding and loss of variation, was tested. The study was based on analysis of seven microsatellite loci in three samples of hatchery‐reared catla and four samples representing wild populations. Pair‐wise estimates of genetic differentiation between samples were low between wild samples (θ rang...

Twenty‐one allozyme loci in samples of wild‐caught and hatchery‐reared Indian major carps from Bangladesh were analysed. Bayesian model‐based clustering analysis revealed the presence of four taxa, corresponding to the three known species along with a fourth unknown taxon present in two hatchery samples. Individual admixture coefficients showed that 24% of all hatchery‐reared fishes were hybrids, whereas a single hybrid was ob...