Moema is a genus of annual killifish related to the Cynolebias/Simpsonichthys group, native to seasonal wetlands of the western Amazon basin - the atlas's 10 species come from Brazil, Peru, and Bolivia. As in other annual killifish, Moema lives in pools that dry out completely on a yearly cycle; eggs are buried in the mud and enter diapause, resuming development only when rain refills the habitat, so the whole population effectively restarts each wet season. What sets Moema apart within the group is size: atlas species run 2–6.5 in, well above the 1–2.5 in typical of most annual killifish, making it one of the larger-bodied genera in this seasonal-pool niche.
Moema is a specialist genus, propagated almost exclusively by dedicated killifish keepers using the standard annual-killifish routine - spawning into peat moss, storing the peat dry through a simulated dry season, then rehydrating it to trigger hatching. It has no meaningful presence in general aquarium retail. Data are sparse for most species in the atlas, with the conservation tally leaning heavily Not Evaluated alongside one Critically Endangered listing, a reminder that many of these fish are documented from only one or a handful of isolated pool systems rather than a continuous range.