Trigonectes
Trigonectes is a genus of fish in the family Rivulidae. These annual killifish are endemic to the Paraguay, upper Madeira and Tocantins basins in far northern Argentina, Bolivia, central Brazil and western Paraguay. They inhabit seasonal swamp, pools and similar habitats in open regions. Once the water disappears, the adults die, but the eggs that have been laid in the bottom remain, only hatching after several months when the water returns.
They are relatively large killifish that are up to in total length depending on the exact species.