Taxonomy & naming
Roeboides bouchellei was described by the American ichthyologist Henry Weed Fowler in 1923. The genus Roeboides Günther, 1864 belongs to the family Characidae and is placed within the subfamily Characinae, a grouping that includes several other scale-eating or insectivorous small characins. Eschmeyer's Catalog of Fishes is the authoritative source for the valid name Roeboides bouchellei Fowler, 1923.
The genus Roeboides is characterised among characids by its strongly compressed, deep body, upturned mouth, and teeth that project visibly beyond the closed jaw — an adaptation associated with the ectoparasitic habit of removing scales from the flanks of other fishes. Several Roeboides species are difficult to separate on external characters alone, and the taxonomy of the group has been revised periodically. Detailed systematic data for R. bouchellei specifically are limited in the accessible literature.
Morphology
Like other members of its genus, Roeboides bouchellei is a strongly laterally compressed, deep-bodied characin with a notably upturned snout and a mouth angled upward. The external teeth protrude visibly outside the closed mouth — the hallmark of the Roeboides lineage — giving the fish a buckled or underbite appearance when viewed from the side. The body is highly reflective and silvery, with the scales producing a mirror-like sheen along the flanks.
Precise meristic data (fin-ray counts, scale rows, maximum standard length) for R. bouchellei are not available in sources consulted for this account. Members of the genus Roeboides are generally small to moderately sized characins, typically reaching a few centimetres in length. Data on colouration and detailed body proportions for this species specifically are sparse.
Habitat
Roeboides bouchellei is a South American freshwater fish; the precise type locality and broader distributional range within South America have not been verified in sources available for this account. Species of the genus Roeboides are broadly distributed across lowland river systems of tropical South America, occupying slow-moving to moderately flowing rivers, floodplain lakes, and forest-edge streams, often in the middle and upper water column.
Water-chemistry parameters for R. bouchellei specifically have not been confirmed. Congeners generally inhabit warm tropical waters with temperatures in the range of 75–82 °F and a broad pH tolerance centred on neutral to mildly acidic conditions, though these values should not be assigned to R. bouchellei without direct evidence.
Feeding
Roeboides species are best known as lepidophages — scale-eaters — that dart at the flanks of other fishes and remove scales with their protruding teeth. This ectoparasitic feeding strategy is supplemented by more conventional prey; Roeboides are not obligate scale-eaters and also take small invertebrates, zooplankton, and insect matter.
No feeding data specific to R. bouchellei are available in sources consulted. The diet is inferred by analogy with well-studied congeners such as Roeboides guatemalensis and R. affinis, which feed on scales opportunistically while also consuming aquatic insects and crustaceans. The protruding teeth are the morphological correlate of the scale-eating habit rather than an indicator of piscivory.
Mating
No published mating observations for Roeboides bouchellei are known from the sources available for this account. Characins of the subfamily Characinae are generally egg-scatterers: males pursue females, spawning occurs in open water or over fine substrate and vegetation, eggs are non-adhesive or weakly adhesive, and no parental care follows.
In the absence of species-specific data, mating behaviour in R. bouchellei is assumed to follow the open egg-scattering pattern typical of the broader Characidae, with no territory defence and no pair bonding.
Breeding
Captive breeding of Roeboides bouchellei has not been documented in sources consulted. By analogy with related characins, breeding would involve egg-scattering over fine-leaved plants or open substrate, adhesive or semi-adhesive eggs, and no parental care — adults would be expected to consume eggs if left with the spawn.
Given the species' rarity in the aquarium trade and the absence of hobbyist breeding records in the accessible literature, specific guidance on inducing spawning, incubation period, and fry rearing cannot be provided reliably for this species.
In the aquarium
Roeboides bouchellei is rarely encountered in the aquarium hobby, and no established husbandry guidelines exist in the literature reviewed. The scale-eating habit of Roeboides species is an important consideration for any aquarist attempting to keep them: conspecifics and tankmates may suffer fin and scale damage, and housing with delicate or slow-moving species is not advisable.
By general principles applicable to small tropical characins, a well-filtered aquarium with warm water (approximately 75–82 °F), soft to moderately hard water near neutral pH, adequate cover, and a diet of small live and frozen invertebrates would provide a reasonable starting point. However, keepers should be aware of the lepidophagous feeding ecology and observe tankmates carefully.
Conservation
Roeboides bouchellei has not been assessed by the IUCN Red List and carries a status of Not Evaluated (NE). No conservation data — population estimates, threat assessments, or range-change data — are available for this species in sources consulted.
As with many small, obscure South American characins, the absence of an IUCN assessment does not imply the species is without pressures; it more often reflects the limited research attention afforded to less commercially or scientifically prominent freshwater fishes. Deforestation, river modification, and pollution across lowland South American river systems represent ongoing background threats for many small characids, though no specific data apply to R. bouchellei at this time.