Taxonomy & naming
Psalidodon goyanensis was described by Alipio de Miranda Ribeiro in 1944, making it one of the mid-twentieth-century additions to a genus that had already accumulated dozens of species across South and Central America. The type locality lies in the Goyaz region of Brazil — the colonial spelling of what is today the state of Goiás in central Brazil — and the species is associated with the upper Tocantins River drainage that drains this part of the Brazilian Cerrado.
The valid name, Psalidodon goyanensis Miranda Ribeiro, 1944, is recognised by Eschmeyer's Catalog of Fishes (Fricke, Eschmeyer & van der Laan) as the authority for Neotropical fish nomenclature. Astyanax is a sprawling genus in the family Characidae with well over 150 described species ranging from Texas in the north to Argentina in the south; recent molecular studies have raised questions about its monophyly, but no formal revision has yet rearranged P. goyanensis into a different genus. The specific epithet goyanensis is a Latinised adjective meaning 'of Goyaz', referring to the type locality state.
This fish was long listed as Astyanax goyanensis; Eschmeyer's Catalog of Fishes places the species in Psalidodon, and the current combination Psalidodon goyanensis is followed here.
Morphology
Detailed morphological data for Psalidodon goyanensis are not available in accessible literature. Like the majority of Astyanax species, it is presumed to be a small, fusiform, laterally compressed characid with a moderately deep body, large eyes, and the characteristic small adipose fin behind the dorsal. Most members of the genus in central Brazilian drainages are silvery, often with a dark humeral spot and a dark caudal peduncle stripe — the typical Astyanax pattern — though the exact markings of P. goyanensis have not been described in sources consulted for this account.
Data on maximum length are not available from sources examined. As a Cerrado Astyanax of unspecified size, it is reasonable to expect an adult length in the range typical for smaller species in the genus, but this is not documented and no figure is given here.
Habitat
Psalidodon goyanensis is associated with the Goyaz region of central Brazil and, by extension, with the headwater systems of the rio Tocantins drainage. The Brazilian Cerrado — the vast tropical savanna biome that covers much of Goiás — is characterised by clear, warm, often seasonal streams with sandy or rocky substrates, gallery forest corridors, and strongly seasonal hydrology tied to a pronounced dry season from May through September.
No specific habitat data for this species — water parameters, depth preferences, or microhabitat associations — appear in the literature available. Cerrado streams draining laterite-rich soils tend toward soft, slightly acidic water, though local variation is considerable depending on substrate and catchment geology. Because the species has not been re-collected or recorded in contemporary surveys that are accessible, its precise range and habitat requirements remain undocumented.
Feeding
No dietary data for Psalidodon goyanensis have been published in sources examined for this account. Astyanax as a genus is predominantly omnivorous, with most studied species consuming a flexible mix of aquatic invertebrates, terrestrial insects fallen to the surface, plant material, algae, and small fishes depending on opportunity and body size. This opportunistic generalism is common across Cerrado-stream characids and likely applies to P. goyanensis, but the species has not been the subject of a stomach-content or stable-isotope study.
In the absence of species-specific data, feeding notes are not provided here. Any information given beyond what sources confirm would risk misrepresenting an essentially undocumented fish.
Mating
No published mating behaviour data are available for Psalidodon goyanensis. Throughout the genus, reproductive behaviour follows the egg-scattering open-spawning pattern characteristic of characids broadly: males pursue females through the water column or into vegetation, eggs are scattered without adhesion to substrate, and no parental care follows. Spawning in Cerrado streams is often linked to the onset of the rainy season, when rising water levels and increased food availability cue reproductively active fish.
Whether P. goyanensis follows this seasonal pattern or spawns more continuously is unknown. No aquarium observations appear to exist for this species.
Breeding
Psalidodon goyanensis has not been documented in captivity and no breeding accounts are available. Based on the reproductive mode typical of the genus, it would be expected to scatter small, non-adhesive eggs freely in the water column or over fine-leaved vegetation or substrate, with the eggs receiving no subsequent attention from either parent. Incubation and larval-development timings have not been recorded.
Because the species is absent from the hobby and from modern ichthyological surveys in accessible sources, captive-breeding protocols cannot be described with any confidence. This section will be updated if new data emerge.
In the aquarium
Psalidodon goyanensis does not appear in the aquarium hobby literature and is not available in the ornamental trade as far as can be determined from sources examined. It has not been imported, bred in captivity, or reviewed by hobby publications. No care guidance can therefore be responsibly provided.
For reference, Astyanax species that are kept in aquaria — notably the cave tetra Astyanax mexicanus and various surface forms sold as Mexican tetras or blind cave fish — tend to be hardy, peaceful schooling fish adaptable to a wide range of water conditions. Whether P. goyanensis would share these characteristics is an open question that only collection and captive-keeping data could answer.
Conservation
Psalidodon goyanensis has not been evaluated by the IUCN Red List; it carries the designation Not Evaluated (NE) and no formal assessment appears to have been conducted. This is not unusual for the many smaller, poorly-known members of Astyanax described from limited material in earlier decades — the genus contains numerous species whose status has simply never been reviewed.
The Brazilian Cerrado, where this species originates, is one of the world's most threatened biodiversity hotspots. Agricultural conversion — primarily for soy production and cattle ranching — has eliminated or degraded a large proportion of native Cerrado habitat, including the gallery forests and stream margins that protect headwater fisheries. Damming of the Tocantins River and its tributaries has also restructured that drainage significantly. Whether P. goyanensis persists, and in what numbers, is unknown; the combination of a restricted type locality, no confirmed recent records, and severe ongoing habitat loss in the region warrants attention in future freshwater fish surveys of Goiás.