<br> Some rivulids are specialized to live in temporary or ephemeral water bodies, and for this reason they are known as annual or seasonal fishes. The fact that these seasonal species inhabit small temporary wetlands, which are easily modified and destroyed, represents a major challenge to their conservation and often puts them at risk of extinction. In Bolivia, one of the countries with the highest recent loss of primary tropical forests, of 32 recorded species, more than half (19) are endemic, and nearly one-third (9) are known only from their type localities. Of the 20 species assessed by the IUCN that occur in the country, eight have been classified in some threat category, and one of them,<br> Moema claudiae<br> (Costa, 2003), is listed as Critically Endangered and possibly extinct. The species had not been recorded in the wild for more than 20 years, and its only known locality—as well as much of its potential distribution area—have been severely degraded and are now occupied by extensive agroindustrial crops. In this work, we report the finding of a population of<br> Moema claudiae<br> recently discovered in a temporary pond within a small forest remnant surrounded by crops. This discovery allows us to provide the first live photographs of the species, along with previously unknown aspects of its biology and ecology. Furthermore, it offers an exceptional opportunity of a second chance to conserve a species that was already believed to be extinct and lost forever.<br>
