The invasive twospot livebearer's biology, its current and potential global distribution.

Abstract

Poeciliids are widely recognised as successful invaders, possessing traits associated with invasion success. Native to Central America and south-eastern Mexico, the twospot livebearer (Pseudoxiphophorus bimaculatus) is a species recently recognised as invasive in both Central and Northern Mexico. Despite its invasive status, limited research exists on its invasion process and the potential threats it poses to native species. In this study, we conducted a comprehensive review of the current knowledge on the twospot livebearer and mapped its current and potential distribution worldwide. The twospot livebearer shares similar traits with other successful invaders within the same family. Notably, it exhibits high fecundity throughout the year and demonstrates resilience to highly polluted and oxygen-deprived water conditions. This fish serves as a host for several parasites, including generalists, and has been extensively translocated for commercial purposes. Recently, it has also been used for biocontrol within its native range. Apart from existing outside its native range, the twospot livebearer, under current climate conditions and if transported there, could readily colonise biodiversity hotspots in tropical zones worldwide, including the Caribbean Islands, the Horn of Africa, North of the Madagascar Island, the south-eastern Brazil, and Asia-Pacific. Given that this fish is highly plastic and our Species Distribution Model, we consider that all areas with a habitat suitability >0.2 should prevent its arrival and establishment. Our findings underscore the urgent need to recognise this species as a threat to freshwater native topminnows and prevent its introduction and spread. This article is protected by copyright. All rights reserved.