Taxonomy & naming
Bedotia tricolor was described by the French zoologist Jacques Pellegrin in 1932. It belongs to the family Bedotiidae, the Madagascar rainbowfishes, a small endemic radiation placed in the order Atheriniformes alongside their relatives the Australasian rainbowfishes (Melanotaeniidae). Eschmeyer's Catalog of Fishes records the valid authority as Pellegrin, 1932; some older references give the year as 1923, but the Catalog of Fishes — which governs the valid name on this site — and FishBase both use 1932.
The genus name Bedotia honours Maurice Bedot (1859–1927), a Swiss systematist from Geneva best known for his work on hydrozoans, after whom the genus was named. The specific epithet tricolor refers to a three-coloured pattern; as with many of Pellegrin's Malagasy descriptions, the name points at the live or preserved coloration of the type material, though detailed colour notes for this species are not widely available in the modern literature.
The family Bedotiidae has been the subject of phylogenetic and biogeographic study — Sparks & Smith (2004) examined the evolutionary relationships of the Malagasy and Australasian rainbowfishes — but B. tricolor itself stays poorly characterised, known from scant material and a single documented locality.
Morphology
Reliable morphometric data for Bedotia tricolor are genuinely sparse: FishBase carries no published maximum length, standard-length, or maturity figures for the species, and its size fields are blank. What can be said is general to the genus. Bedotia are small, elongate, laterally compressed rainbowfishes with the family's characteristic divided dorsal fin — a short anterior dorsal followed by a longer posterior dorsal — and a slender, streamlined body suited to flowing water.
The epithet tricolor indicates a three-coloured pattern, which in Bedotia typically involves a combination of body coloration with contrasting markings or fin edging along the median fins; many congeners show dark lateral stripes and red, white, or black margins on the tail and dorsal and anal fins. In the absence of detailed published colour descriptions or photographs for this species specifically, finer points of its appearance are best treated as uncertain rather than asserted.
FishBase estimates a trophic level of roughly 2.6 and gives length–weight parameters (a = 0.00389, b = 3.12 on total length in centimetres) derived from the species' close relatives rather than from large series of measured specimens — a reminder that these are modelled values, not direct observations of B. tricolor.
Habitat
Bedotia tricolor is endemic to Madagascar and, on the record, extraordinarily localised: it has only been recorded from a single tributary of the Faraony River, in the southeastern part of the island. That pinpoint distribution is the defining fact of the species' biology and the direct cause of its conservation status. A fish known from one small stretch of one watershed has no geographic buffer against local disturbance.
FishBase characterises the species as a freshwater, pelagic, tropical fish of rivers, consistent with the genus, whose members typically inhabit clear, flowing forest streams. Like other Bedotia, B. tricolor is presumed to favour well-oxygenated running water with cover, though specific measurements of temperature, pH, depth, or flow for its actual locality are not available in the sources at hand.
The forest streams of southeastern Madagascar that the genus occupies are under pressure across the region from deforestation, sedimentation, and the introduction of non-native fishes — the same broad threats that have pushed much of the island's freshwater fauna toward extinction, and which bear directly on a species confined to a single tributary.
Feeding
No diet study specific to Bedotia tricolor is available, so its feeding habits are inferred from the genus. Bedotia rainbowfishes are small, active, mid- and upper-water carnivores to omnivores that feed largely on aquatic and terrestrial invertebrates — insect larvae, small crustaceans, and insects taken at or near the surface — supplemented by other small drifting prey carried by the current.
FishBase's estimated trophic level of about 2.6 for B. tricolor is consistent with a diet dominated by small invertebrates rather than plant material, placing it as a low- to mid-level predator within its stream community. As a stream-dwelling rainbowfish it would be expected to forage opportunistically, picking food items from the water column and surface film.
Because the species is effectively absent from the aquarium trade, there is no body of captive feeding observations specific to it; any account of its feeding in captivity would be an extrapolation from its congeners rather than a documented fact.
Mating
Direct observations of courtship and mating in Bedotia tricolor are not available in the sources at hand, and the species' rarity means little has been recorded. What follows is therefore drawn from the genus and should be read as a genus-level analogue rather than verified detail for this species.
Bedotia rainbowfishes are egg-scattering, plant-associated spawners with no parental care. In congeners that have been kept and bred, males court females with fin displays and heightened colour, and spawning takes place over fine-leaved vegetation or other fine substrate, often most actively in the morning hours — a pattern broadly shared across the rainbowfishes of both the Malagasy and Australasian families.
Whether B. tricolor differs from its relatives in any aspect of its reproductive behaviour is simply unknown. Given that it is known from a single tributary and is rarely encountered, its natural breeding ecology has not been documented in detail.
Breeding
There is no published account of captive breeding for Bedotia tricolor, and the species is essentially unavailable to aquarists, so a species-specific breeding protocol cannot be given here without fabrication. The notes below describe how the genus is known to reproduce and are offered only as context.
Bedotia are egg-scatterers that deposit adhesive eggs onto fine-leaved plants or spawning mops over an extended period rather than in a single clutch, with a female releasing a few eggs at a time across many days. The eggs hang from the spawning medium by fine filaments, hatch after a number of days, and the parents give no care and may eat the eggs and fry. These traits are documented for kept congeners such as B. madagascariensis and B. geayi.
For B. tricolor specifically, incubation time, fry size, and rearing requirements are undocumented. Any aquarist attempting to breed the species — were stock to become available through a conservation programme — would be working from genus-level analogues, and that uncertainty should be stated plainly rather than papered over with borrowed numbers.
In the aquarium
Bedotia tricolor is, for practical purposes, not an aquarium fish. As a single-locality Critically Endangered species it is absent from the ornamental trade, and there is no body of husbandry experience specific to it. Aquarium coverage of the genus exists only for the widespread congeners B. madagascariensis and B. geayi, which are the fish hobbyists actually keep when they keep a "Madagascar rainbowfish."
For those congeners, the general approach is a densely planted tank with open swimming space, neutral to slightly alkaline water (around pH 7.0–8.0), and temperatures in the low-to-mid 20s Celsius (roughly 72–79 °F / 72–79 °F), with the fish kept in groups as active, peaceful schoolers. These are genus-level guidelines and are explicitly not verified for tricolor; the species' true preferences in its single Faraony tributary have not been measured.
The honest summary is that this is a fish of conservation concern rather than of the hobby. If it has an aquarium future at all, it is likely to be within managed captive-breeding or ark programmes aimed at preserving the species, not in general fishkeeping.
Conservation
Bedotia tricolor is assessed as Critically Endangered (CR) on the IUCN Red List (species ID 2722). FishBase reports the listing under criteria B1ab(iii,v) with an assessment date of 23 June 2016, while an earlier IUCN assessment of Madagascar's freshwater fishes listed the species as CR under criteria B1ab(i,iii). The driving rationale across assessments is the same: the species has only ever been found in one tributary of the Faraony River, an extreme single-locality range that leaves it acutely vulnerable to habitat loss and degradation.
The pressures on southeastern Madagascar's freshwater systems — deforestation and the sedimentation that follows, agricultural encroachment, and the spread of introduced fishes — fall heavily on a species with nowhere else to live. A fish restricted to a single small watercourse has no reservoir population to absorb local declines, which is precisely why the B1 (restricted-range) criteria place it in the Critically Endangered category.
Meaningful conservation for B. tricolor depends on protecting the specific habitat it occupies and, potentially, on ex-situ safeguarding given how little margin remains. It is harmless to humans and of negligible fishery value (FishBase scores its fishing vulnerability at 10 of 100); its significance is as an endemic component of Madagascar's imperilled freshwater biodiversity rather than as a resource, and its survival is far from assured.