new status – from subgenus to genus:
Gymnolebias   Costa, 2008

new combination from Austrolebias for Uruguay:
Gymnolebias gymnoventris (Amato, 1986)

published in:
Alonso, F., G.E. Terán, W.S. Serra Alanis, P. Calviño, M.M. Montes, I.D. García, J.A. Barneche, A. Almirón, L. Ciotek, P. Giorgis & J. Casciotta (2023):
From the mud to the tree: phylogeny of Austrolebias killifishes, new generic structure and description of a new species (Cyprinodontiformes: Rivulidae).
Zoological Journal of the Linnean Society, early view, 30 p., doi: 10.1093/zoolinnean/zlad032

abstract (from publication):
Killifishes (Cyprinodontiformes) are a group of fish that include a high proportion of small-bodied species living in seasonal aquatic habitats, with narrow geographical distributions and high human impact. They are among the most vulnerable vertebrates in the Neotropical region, with nearly half of the species in threat categories. Herein, we propose a new phylogenetic hypothesis of the Rivulidae genus Austrolebias, based on 10 genes (six nuclear and four mitochondrial) and 191 morphological characters, including 90% of the total valid species of this genus. An updated definition and diagnosis of the existing subgenera of Austrolebias is provided, and these are erected to genera. Also, four new genera are erected to accommodate the taxonomy of the group to the current phylogenetic hypothesis. Additionally, we describe Argolebias guarani sp. nov., from a seasonal pond in the Middle Parana River basin, which is diagnosed by a unique colour pattern. This addition reinforces this area as a biodiversity hotspot of endemicity and highlights the importance of this region for conservation. Data on the ontogenetic changes in colour pattern, chorion ornamentation of the egg and ecology of this species are also provided.