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

Garcialebias arachan is known only in seven locations, in Uruguay and Brazil. The extent of occurrence (EOO) equates to less than 20,000 km². The biggest threat to the species is the draining of ponds for rice cultures, as well as the use of the species for ornamental purposes in some of its range; both inferred to be causing a continuing decline in habitat quality. As such, the species is assessed as Vulnerable. 

The species is distributed in the Negro river basin, Uruguay, and in the adjacent drainage of the Tacuarí river, Mirin lake basin, part of Patos lake system (GBIF 2019, CRIA 2020, Fricke et al. 2020). The type locality is a wetland area next to route 7 and Arroio Chui, in the drainage of Tacuarí river, Cerro Largo department, Uruguay. The first and only record of this species in Brazil dates from 2008, in a temporary flooded area of around 30 m², 5 km from the border with Uruguay, in the low drainage stroke of Jaguarão-Chico river, Jaguarão river basin, Patos-Mirin lagoon system, Pedras Altas municipality (ICMBio/MMA 2018).

There is no population data available. Five collection campaigns were made in the area around the lower Jaguarão-Chico river, Jaguarão river basin, Patos-Mirin lagoon system, Pedras Altas municipality, Rio Grande do Sul, with only one population registered, being abundant in this locality. At the time of this record, females were more abundant and males presented bigger sizes (ICMBio/MMA 2018).

The species occurs in small sized wetlands, of little depth and dense aquatic vegetation, inserted in rural environments. In the biotopes where the species was recorded, the presence of Gravatás (Eryngium sp., Apiaceae family plant) was notable (ICMBio/MMA 2018).

The primary threat to this species is the draining of its habitats and their alteration for rice cultivation. In the region where it is found, the remaining wetlands are being converted into rice and soybean fields, as well as forestry, leading to habitat fragmentation. In Uruguay, populations may face pressure and capture for aquarium purposes (ICMBio/MMA 2018). 

In Uruguay there is pressure and capture for fishkeeping.

Additional studies are essential to achieve a more precise mapping of the species' distribution in Brazil. Urgent measures are required to safeguard and restore the species' habitat. Despite the existence of priority areas for biodiversity conservation in the Jaguari River basin, no officially protected areas have been designated. The expansion of agriculture mandates thorough environmental licensing studies, ensuring careful consideration of the potential presence of the species (ICMBio/MMA 2018). In Brazil A. arachan was categorized as Critically Endangered (CR), according to the Brazilian national red list (ICMBio/MMA 2018).