Taxonomy & naming
Simpsonichthys santanae (Shibatta & Garavello, 1992) is the valid name in the Catalog of Fishes. The parentheses show that it was originally described in a different genus. It belongs to the family Rivulidae, in a genus of South American annual killifish.
Morphology
FishBase gives a maximum of 1 in TL for males or unsexed fish. See the original description for diagnostic characters.
Habitat
The type locality is the right bank of the Ribeirão Sant'Ana (Santana) in the Distrito Federal, 2,461 ft from the border with Goiás, Brazil (about 16°02'S, 47°46'W), Cerrado savanna country with seasonal pools. FishBase places it in freshwater in the Paraná River basin and calls it non-migratory.
Feeding
Annual killifish are carnivores feeding on small aquatic invertebrates. Specifics for this species are not recorded.
Mating
Reproductive behaviour for this species is not specifically recorded.
Breeding
FishBase describes a bottom spawner with about three months of incubation, and notes that the species is difficult to maintain in aquaria. As with other annual killifish, adults die when the pool dries and the eggs survive in the mud; hobbyists collect eggs from peat.
In the aquarium
Sold by Dan's Fish. FishBase notes it is difficult to maintain. Keep as a species tank with a peat spawning box; annual killifish are short-lived.
Conservation
The IUCN Red List lists Simpsonichthys santanae as Endangered (EN), meaning it faces a very high risk of extinction in the wild; FishBase does not give the assessment year. The type area lies in and around Brasília, where urban growth and agriculture threaten seasonal pools.