ENEndangered

Killifish

Austrolebias viarius

Austrolebias viarius is a small, colorful annual killifish endemic to temporary wetlands in Uruguay and southern Brazil. Males display vibrant blue and yellow coloration during breeding season, while females are more subdued in appearance.

1

Countries

01Classification

Taxonomy & Classification

Kingdom

Animalia

Phylum

Chordata

Order

Cyprinodontiformes

Family

Rivulidae

Genus

Austrolebias

Killifish belongs to the family Rivulidae, order Cyprinodontiformes, within the unknown class.

02Description

Species Profile

Austrolebias viarius is a small, colorful annual killifish endemic to temporary wetlands in Uruguay and southern Brazil. Males display vibrant blue and yellow coloration during breeding season, while females are more subdued in appearance. These fish play a crucial role in temporary pond ecosystems as both predators of invertebrates and prey for birds and larger fish.

Austrolebias viarius faces severe threats from habitat destruction due to agricultural expansion, urban development, and wetland drainage in its limited range. The species' dependence on temporary pools makes it particularly vulnerable to hydrological changes and pollution from agricultural runoff.

Key Facts

IUCN StatusEndangered (EN)
GroupOther invertebrates
03Habitat

Habitat & Distribution

This killifish inhabits shallow, temporary pools and seasonal wetlands that fill during rainy periods and dry completely during drought seasons. These ephemeral water bodies are typically found in grassland depressions with muddy substrates that preserve the species' drought-resistant eggs.

FRESHWATERMajor
04Threats

Threats

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IUCN Red List: Endangered

Austrolebias viarius faces severe threats from habitat destruction due to agricultural expansion, urban development, and wetland drainage in its limited range. The species' dependence on temporary pools makes it particularly vulnerable to hydrological changes and pollution from agricultural runoff.

Habitat loss from agricultural expansion

HighOngoing

Urban development and infrastructure

HighOngoing

Wetland drainage and hydrological modification

HighOngoing

Climate change affecting seasonal pool dynamics

MediumOngoing

Water pollution from agricultural chemicals

MediumOngoing
06Range

Found in 1 Country

Community

Community Sightings

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07Sources

Sources & Attribution

How to Cite

IUCN: IUCN (2025). The IUCN Red List of Threatened Species. Version 2025-1. Available at: https://www.iucnredlist.org. doi:10.2305/IUCN.UK.2025-1.RLTS

GBIF: GBIF.org (2025). GBIF Home Page. Available at: https://www.gbif.org

This page: SpeciesRadar (2025). Killifish (Austrolebias viarius). SpeciesRadar: Intelligence for Earth's Biodiversity. Available at: https://speciesradar.org/species/killifish-2349022

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