fish · Characidae
Bucktooth tetra
Exodon paradoxus
Wild range: Amazon and Tocantins/Araguaia basins; also Orinoco, Río Branco, and upper Essequibo (Brazil, Colombia, Guyana, Venezuela) (South America)
At a glance: Bucktooth tetra care
Compiled reference information. Review the care notes and original sources below.
What temperature is listed for Bucktooth tetra?
The compiled profile lists 23.0–28.0 °C for Bucktooth tetra (Exodon paradoxus). Check the original sources below for context and differing recommendations.
What tank size is listed for Bucktooth tetra?
The profile lists a minimum tank volume of 55.0 US gallons (208.0 liters). Volume alone does not establish suitability; consider dimensions, group size and other inhabitants alongside the full care notes.
What pH is listed for Bucktooth tetra?
The compiled profile lists a pH of 5.5–7.5. Review the cited care sources alongside the other water parameters in this profile.
Natural habitat
Monotypic lepidophagous characin (subfamily Exodontinae) of South American sandy river shallows and floodplain margins; specialised scale-eater that also takes insects; highly active midwater shoaler with two dark body blotches and reddish-yellow fins; trade staple among predatory/oddball tetras but unsuitable for mixed community tanks (SF, FishBase, PFK, Wikipedia).
Where they are found
Catalog primary locked as Exodon paradoxus Müller & Troschel, 1844 per trade, ITIS TSN 162857 (valid; common names bucktooth/bucktoothed tetra), FishBase SpecCode 5145 (accepted), Eschmeyer’s Catalog of Fishes / Wikipedia CoF (type locality Essequibo River, Guyana; Characidae: Exodontinae; monospecific genus Exodon), and IUCN Least Concern (FishBase assessment 2021-03-04; Wikipedia cites Lima 2023). Synonyms include Hystricodon paradoxus, Epicyrtus exodon / Epicyrtus paradoxus (ITIS synonym list; AquaInfo; Wikipedia). Trade aliases: Bucktoothed tetra, Exodon tetra, Scale-eating tetra. No newer CoF rename displacing Exodon paradoxus; genus remains monotypic — no trade ambiguity with another species under this name.
Aquarium care
Advanced species-only aggressive shoaling tetra for a long, wide, tightly covered tank (SF, TFH, AquaInfo, PFK, tropical-fish-keeping, aqua-fish.net). Lock ≥55 US gal / ~208 L (TFH + tropical-fish-keeping + AquariumStoreDepot 55 gal floor; AquaInfo ~200 L / 120 cm length for ~10; SF prefers ~243 L / 120×45×45 cm — upgrade footprint for groups of 15–25+). Soft sand, driftwood, and heavy planting or visual barriers around open midwater swimming space; strong efficient filtration with moderate flow/powerhead; secure lid (jumpers). Water locked 23–28°C, pH 5.5–7.5, GH 0–18 (SF+FishBase+AquaInfo 23–28 / 5.5–7.5; FishBase dH 0–20; aqua-fish.net 22–28 / 0–18°N / pH 5.5–7.5 — locked overlapping band; PFK prefers pH ≤7.0 and 24–28°C). Keep a large group bought together (≥12; 15–25+ better) so intra-shoal aggression is diffused — small groups often attrition to one survivor (SF, PFK, tropical-fish-keeping; AquaInfo warns cannibalism in undersized tanks).
Feeding
Carnivorous lepidophage; wild diet insects plus fish scales (SF, FishBase, PFK). In aquaria feed varied meaty foods: bloodworms, chopped prawn/mussel, earthworms, lancefish/Mysis/krill, plus quality pellets/flakes once trained (SF, aqua-fish.net, tropical-fish-keeping, AquaInfo). Feed generously so the feeding frenzy does not redirect onto weaker tankmates; no live feeder fish required.
Compatibility
Not communitysafe and not nanook. Relentlessly strips scales/fins from silver or shiny fish — even larger predators and many cichlids fail as tankmates (SF, TFH, PFK, AquaInfo). Best as a dedicated species tank. Scaleless/non-reflective loricariids or robust pimelodids are the least-bad occasional companions and still risky; add Exodon last and keep a hospital tank ready (TFH, SF). community_safe false.
Breeding
Egg scatterer; captive breeding uncommon but documented (SF, tropical-fish-keeping, AquaInfo). Condition a large shoal on live/frozen foods; move a conditioned pair to a separate soft acidic tank (pH 6.0–6.5, low GH) with fine plants or egg-protecting mesh; a large warmer water change (~40–50%) may induce spawning. Remove parents immediately. Hatch ~2–3 days; raise on Artemia; expect cannibalism and size-grade fry.
Sources
Compiled from multiple independent care sheets — not copied from a single site.