Conservation Strategies in the South American Annual Killifish of the Austrolebias sensu lato Linked to the Riparian Wetlands Zones

Abstract

The South American annual killifish of the Austrolebias sensu lato constitute an extensive species group and serve as a remarkable evolutionary model, inhabiting riparian wetlands in the La Plata River grasslands. This region contains three major areas with allopatrically distributed local and regional endemic species assemblages. At present, the IUCN Red List includes nearly 75% of the species in the Austrolebias genus group. A synapomorphic characteristic of this group is their expanded genome size. Vicariance/dispersal and secondary contact have played key roles in the diversification of most genera within this group, explaining their current distribution across endemic areas. Riparian wetlands are transitional zones that support exceptionally high levels of biodiversity and productivity. The effective conservation of biodiversity in these zones enhances connectivity between river corridors and floodplains, linking aquatic and wetland habitats where annual killifish inhabit, while ensuring the long-term evolutionary potential of populations. Due to these unique characteristics, the annual killifish of the Austrolebias genus group could be an umbrella species, providing benefits in the conservation of riparian wetlands in the temperate regions of the La Plata River grasslands, and ensuring both biota integrity and long-term evolutionary processes.