Austrolebias
Austrolebias nigripinnis, also known as blackfin pearlfish, is an ephemeral killifish in the family Rivulidae. These annual killifish lives in temporary water bodies during the season, thus it undergoes its entire life cycle within the periodically drying-up temporary ponds in the Río de la Plata, Patos–Mirim and Mamoré basins in South Americal
Most species are small, less than in total length, but a few reach, making them some of the largest killifish.