Mitochondrial DNA authenticates Gambusia affinis (Baird and Girard, 1853) as the invasive mosquitofish in Taiwan.
Two mosquitofishes, the western, Gambusia affinis (Baird and Girard, 1853) and eastern, G. holbrooki Girard, 1859, species, were treated as a single lineage from 1882 to 1988. Here, we assess whether the mosquitofish introduced into Taiwan in 1911 for mosquito control really was G. affinis, as documented, or G. holbrooki or a combination of both. Using mitochondrial cytochrome b as a genetic marker, we sequenced 78 mosquitofish specimens sampled from around Taiwan and found only one haplotype. Our phylogenetic analyses support that only the western mosquitofish (G. affinis) has invaded Taiwan. However, since G. holbrooki is present in the Taiwanese aquarium market, future invasion by the eastern mosquitofish is very likely.