Hypsolebias is a genus of annual killifish endemic to Brazil, split in recent decades from the older, broader genus Simpsonichthys as the South American annual-killifish group was revised. Like other annual killifish, they live in temporary pools and seasonal wetlands — often in the Cerrado and other seasonally dry landscapes — that fill during the rains and dry out completely for part of the year; the adult fish die when their habitat dries, but their eggs survive buried in the substrate in a dormant state (diapause) and hatch when the pools refill, giving the group its extremely short, fast life cycle. Many species are strikingly colored, with males in particular showing intense reds, blues, and patterning used in courtship. The atlas covers 19 species, adult size roughly 1.5–3 in.
Hypsolebias are prized among specialist killifish keepers and breeders specifically for that vivid coloration and the novelty of raising fish from dried, stored eggs rather than free-swimming stock — a niche but devoted corner of the hobby, not mainstream fishkeeping, and essentially unseen in general fish stores. The conservation picture for the genus is genuinely concerning: the atlas's IUCN tally includes seven species rated Endangered and three Vulnerable alongside a scatter of Least Concern, Data Deficient, and Not Evaluated entries, a pattern consistent with Brazil's annual killifish generally being highly localized, single-pool or single-drainage endemics that are easily lost when seasonal wetlands are converted to agriculture.