We follow Alonso et al. (2023) in considering Garcialebias a valid genus, rather than a synonym of Austrolebias.

Garcialebias charrua occurs in Uruguay and Rio Grande do Sul (Brazil), registered in 9-10 locations, with a minimum extent of occurrence of c. 23,000 km². The biggest threat to the species is the continuing decline in habitat quality, inferred primarily due to draining of wetlands and sustainable energy projects. However, it is considered to be locally abundance in much of its range; as such, the species qualifies for Near Threatened currently. 

This species occurs on coastal plains adjacent to Mirim lake, between Rio Grande and Chuí, Rio Grande do Sul state (ICMBio/MMA 2018, GBIF 2019, CRIA 2020, Fricke et al. 2020). In Uruguay's extreme northeast it occurs in areas adjacent to Arroio Chuí in Rocha department.

There is no population data available. Garcialebias charrua has a relatively broad distribution, being relatively abundant; however, the habitat of the species is severely impacted by ongoing threats.

Garcialebias charrua is an annual fish that reaches around 4.7 cm in length. Like other species of cynolebiasine fishes, it presents considerable sexual dimorphism; males being larger, more colourful, and having dorsal and anal fins with more rays compared to females. It occurs in syntopy in Chuí stream with three other species of annual fish: Cynopoecilus melanotaenia, Acantholebias luteoflammulatus and Titanolebias prognathus. Generally, it inhabits temporary wetlands, with little to no cover by arboreous species, but with dense aquatic vegetation. It is also frequently present in drainages and water channels rectified for rice plantations, if those keep the hydrologic temporality and aquatic vegetation. Like all seasonal aplocheiloid killifishes, it has a short life cycle, early sexual maturity and diapausing eggs (ICMBio/MMA 2018). Adults usually die after the water bodies dry at the end of spring (M. Loureiro and J. Bessonart pers. comm. 2024).

The destruction of the wetlands and swamps occupied by the species in Chuí region, especially in the Santa Vitória do Palmar municipality (one of the biggest municipalities with the highest rice production in Rio Grande do Sul), for rice plantation, makes the biggest threat to the preservation of G. charrua. Besides that, recently the soy cultures of varieties better suited for damper weather have also gained space within the species' range, fragmenting the habitat. In the species' distribution area, several wind power plants and transmission lines are also being built. In Arroio Chuí floodplain, the subpopulations of the species and other killifish species (A. luteoflammulatus, Titanolebias prognathus and Cynopoecilus melanotaenia) are at imminent risk by draining and landfilling of wetlands in the area (ICMBio/MMA 2018).

In Uruguay, the major threats are the desiccation of ponds because of soybean and rice crops too, whilst herbicide and pesticide release also negatively affects the viability of eggs and the growth of fish (M. Loureiro and J. Bessonart pers. comm. 2024). Urban expansion may also cause major impacts. Little is known about these threats, but unregulated collection and eucalyptus plantations could also impact the species (M. Loureiro and J. Bessonart pers. comm. 2024). 

In Uruguay, there may be unregulated capture of these fishes by aquarists as there are no extraction laws in place (M. Loureiro and J. Bessonart pers. comm. 2024). 

Garcialebias charrua is listed as a target species of the National Action Plan for Endangered Rivulidae Conservation - PAN Rivulideos (ICMBio 2013). There is a need to identify and secure the protection to the species remaining habitat, preventing the draining, grounding, or any sort of intervention. Pampa’s Annual Fish project data (IPPampa) demonstrates that one of the most important areas for species conservation is Arroio Chuí floodplains, in Chuí, and Arroio Del Rey floodplains, in Santa Vitória do Palmar (RS) (ICMBio/MMA 2018). In Brazil, the species was categorized as Endangered (EN), according to the Brazilian national red list (ICMBio/MMA 2018). In Uruguay, some localities are within protected areas (M. Loureiro and J. Bessonart pers. comm. 2024).