Taxonomy & naming
The species was described in 2021 by Bentley, Grant and Tencatt in the journal Zootaxa, as a new arc-striped Corydoras. Its type locality is the río Blanco, near its confluence with the río Tapiche, in Soplín District, Requena Province, Department of Loreto, Peru; it is reported from the Blanco and Ucayali river basins of the Peruvian Amazon. Although the fish is sometimes spoken of loosely as a Brazilian cory in the trade, the published distribution is Peruvian, and we record it that way.
It was described in the genus Corydoras Lacépède, 1803 (family Callichthyidae). That genus, with well over 170 species, proved not to be a single natural lineage, and the 2024 revision by Dias, Tencatt and colleagues split it into several genera, among them Brochis, Hoplisoma, Gastrodermus and Osteogaster. Under that scheme this species becomes Brochis bethanae — Brochis being the lineage of the larger, often long-snouted, many-rayed-dorsal corys. We keep the familiar heading 'Corydoras bethanae' while noting the current combination. The specific name is a patronym, honouring a person rather than describing the fish.
Morphology
This is a comparatively elongate, long-snouted cory; the female holotype measured about 2 in in standard length, and the species is a 'longnose' form. Like all Corydoradinae it is armoured rather than scaled, with two overlapping rows of bony scutes down each flank, a hard helmet-like head and three pairs of barbels around the downturned mouth; the pointed snout and long mesethmoid bone are part of its diagnosis.
Its signature is the colour pattern: a single long, wide, arched and continuous black stripe that runs parallel to the dorsal profile of the body, set against a pale, flesh-toned ground. A dark, mask-like blotch crosses the eye and, in most specimens, remains clearly separate from the arched stripe rather than fusing with it. The dorsal and pectoral fin spines bear laminar serrations, and the ventral surface of the trunk is covered by small, non-coalescent platelets — fine characters used to separate it from similar long-snouted relatives such as the narcissus group.
Habitat
Corydoras bethanae lives in the lowland western Amazon of Peru, in the Blanco and Ucayali drainages. The type locality, the río Blanco near its meeting with the río Tapiche, lies in the Ucayali floodplain — a lowland forest landscape of slow rivers, blackwater and clearwater tributaries, oxbow lakes and seasonally flooded forest over sand, mud and leaf litter.
Precise field water chemistry has not been widely published for the species; by the character of the region these are warm lowland waters, generally soft and acidic to near-neutral, in the broad 75–82 °F band typical of the western Amazon. Like other corys it is a facultative air-breather, surfacing to gulp air and absorb oxygen through a vascularised hindgut, which suits the warm, shallow, oxygen-poor backwaters it frequents.
Feeding
As a Corydoradine, it is a benthic omnivore and detritivore that sifts the soft bottom, burying its long snout and barbels to taste out small invertebrates, insect larvae, worms and organic detritus and expelling cleaned substrate through the gills. The longer snout of this 'longnose' form is suited to probing more deeply into sand and litter. In the aquarium it would be expected to take sinking tablets, granules and larger flakes along with live and frozen foods such as bloodworm, Daphnia and Tubifex, used to condition fish for spawning, in line with its relatives.
Mating
No spawning observations specific to Corydoras bethanae have been published. By the well-documented pattern of the family it would be an egg-laying shoaler with no pair bond and the characteristic 'T-position' courtship: a ready female cleans a site, a male places himself at right angles to her head, she appears to take his milt at the mouth, and the few eggs clasped in a basket of her pelvic fins are fertilised and pressed onto a firm surface, the cycle repeating a few eggs at a time. This account is inferred from close relatives rather than observed in this species.
Breeding
There is no published aquarium breeding report for Corydoras bethanae, which is a recently described and uncommon fish. Based on its relatives it would be expected to spawn in the standard Corydoradine fashion — a cool, generous water change as a rainy-season trigger, small batches of adhesive eggs laid on firm surfaces, and no parental care, with adults apt to eat the eggs unless eggs or parents are moved. Eggs of related corys hatch in roughly three to five days and the fry take microworm, baby brine shrimp and powdered foods once the yolk is absorbed. We flag the absence of a confirmed report rather than presenting borrowed detail as fact.
In the aquarium
A handsome long-snouted cory of interest mainly to specialists and rarely offered, Corydoras bethanae would need the standard, non-negotiable cory care. It is a shoaling fish, stressed when kept alone or in pairs — keep six or more. Long-snouted corys especially want a generous footprint and an open bottom to forage, so a tank of around 23.5–31.5 in with ample floor area is appropriate.
Substrate is critical: soft sand or very smooth fine rounded gravel only, since sharp or coarse grit erodes and infects the barbels and snout these fish push deep into the bottom — a real risk for a longnose form. Border an open feeding zone with driftwood and planting and provide shade. Lean toward warm (about 75–82 °F), soft, slightly acidic, well-filtered and well-oxygenated water with regular changes, reflecting its western-Amazon origin. It is a peaceful community fish suited to tetras, pencilfish and calm dwarf cichlids. Net with care because the fin spines snag, and transport gently — a distressed cory can release skin toxins that may kill the group in the confined volume of a bag.
Conservation
Corydoras bethanae has not been assessed by the IUCN Red List, so its conservation status is formally Not Evaluated — unsurprising for a species described only in 2021. Its known range in the Blanco and Ucayali basins lies in a lowland Amazonian region that is still relatively intact in places but faces growing pressure from deforestation, agriculture, oil and gas activity and river-traffic development. Because the species is newly described and its full distribution is not yet mapped, a formal evaluation, and basic ecological study, would be valuable before assuming it is secure.