Moema is a genus of fish in the family Rivulidae. These annual killifish are mostly restricted to the Amazon basin in Bolivia, Brazil and Peru, but a few inhabit the upper Essequibo basin in Guyana, upper Orinoco basin in Venezuela and upper Paraguay basin in Brazil. They inhabit temporary waters, such as swamps or ponds, in primary forests. Once the water disappears, the adults die, but the eggs that have been laid in the bottom remain, only hatching after 3–10 months when the water returns. They rapidly reach adult size, but generally only live a few months after hatching, although captives (not subjected to disappearing water) can live longer.

They are small fish, with the largest species up to in total length.

Species Moema was first described in 1989, having formerly been included in the Pterolebias. In 1998, it was suggested that several Moema species should be moved to their own genus, Aphyolebias. Some, including FishBase, continue to recognize both Moema and Aphyolebias. The distinction between them is not well-defined and genetic studies have shown that Moema is paraphyletic if not including Aphyolebias, leading several authorities such as Catalog of Fishes to consider the latter a junior synonym of former.

According to the Catalog of Fishes, there are currently 22 recognized species in this genus:

Moema apurinan W. J. E. M. Costa, 2004 Moema beltramonorum Valdesalici, 2023 Moema beucheyi Valdesalici, D. T. B. Nielsen & Pillet, 2015 Moema boticarioi (W. J. E. M. Costa, 2004) Moema claudiae (W. J. E. M. Costa, 2003) Moema funkneri Valdesalici, 2019 Moema hellneri W. J. E. M. Costa, 2003 Moema heterostigma W. J. E. M. Costa, 2003 Moema juanderibaensis Drawert, 2022 Moema kenwoodi Valdesalici, 2016 Moema manuensis (W. J. E. M. Costa, 2003) Moema nudifrontata W. J. E. M. Costa, 2003 Moema obliqua (W. J. E. M. Costa, Sarmiento & Barrera, 1996) Moema pepotei W. J. E. M. Costa, 1992 Moema peruensis (Myers, 1954) Moema piriana W. J. E. M. Costa, 1989 Moema portugali W. J. E. M. Costa, 1989 Moema quiii Huber, 2003 Moema rubrocaudata (Seegers, 1984) Moema schleseri W. J. E. M. Costa, 2003 Moema staecki (Seegers, 1987) Moema wischmanni (Seegers, 1983) Synonyms Moema ortegai W. J. E. M. Costa, 2003, synonym of Moema quiii Huber, 2003

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