−15%
Moderate
Cardinal Tetra (Paracheirodon axelrodi)
23–27°C · pH 4.5–7 · 60L
£2.54£2.99
Sailfin Tetra is a subtle South American characin for shaded planted or blackwater-style aquariums, best kept in mature soft water with calm tank mates.
Adult size is the maximum length this species reaches at full maturity (scientific sources). The livestock you receive will be younger and smaller — pick a size variant above for the actual shipping size. Photos are AI-enhanced, so the animal may show subtle colour or marking differences.
Crenuchus spilurus
Sailfin Tetra is a subtle South American characin for shaded planted or blackwater-style aquariums, best kept in mature soft water with calm tank mates.
Adult size is the maximum length this species reaches at full maturity (scientific sources). The livestock you receive will be younger and smaller — pick a size variant above for the actual shipping size. Photos are AI-enhanced, so the animal may show subtle colour or marking differences.
Maintain these water conditions for optimal health and vibrant colors
Sailfin Tetra (Crenuchus spilurus) is a quiet South American characin for aquarists who enjoy shaded, natural aquariums rather than bright, busy community tanks. Its appeal is subtle: a slim body, a dark tail spot, an impressive sail-like dorsal fin on mature males and a deliberate way of moving through leaf litter, wood and plant cover.
This is best treated as a specialist soft-water tetra, not as a throw-in shoaling fish. It rewards a calm, mature setup with gentle flow, warm stable water, fine foods and tank mates that leave space around the lower and middle levels.
| Scientific name | Crenuchus spilurus |
|---|---|
| Common names | Sailfin Tetra, Sailfin Characin, Mojarita |
| Family | Crenuchidae |
| Natural range | Northern South America, including Amazon, Orinoco and Guiana drainage areas |
| Adult size | Usually about 5-6 cm |
| Best kept as | Single fish, pair or small structured group |
| Temperament | Peaceful with other species; males can guard small territories around cover |
| Diet type | Micropredator; prefers small live, frozen and fine prepared foods |
Sailfin Tetras behave differently from many open-water tetras. FishBase notes that the species is more solitary and territorial than most characoids, and practical aquarium profiles describe a shy, cover-loving fish that does best around leaf litter, roots, branches and shaded margins. That means the aquarium layout matters as much as the water numbers.
Think of it as a small character fish for a quiet South American display. In a bare, bright tank with fast feeders it can become hidden and underfed. In a darker aquascape with visual barriers, it shows better shape, posture and courtship behaviour.
| Minimum aquarium | 60 litres for one or a pair; more space for a group |
|---|---|
| Layout | Fine sand or smooth substrate, driftwood, roots, plants and leaf litter |
| Lighting | Subdued lighting or floating plants to create shaded areas |
| Flow | Gentle to moderate; avoid blasting the resting areas |
| Cover | Use several shelters and broken sight lines if keeping more than one male |
| Maturity | Best in an established aquarium with stable water quality |
A blackwater-style aquarium suits this species beautifully, but it does not need extreme water if the system is stable and clean. Wood, botanicals and plants give the fish confidence, while open front space lets you actually see it. Leave small shaded territories rather than one open race track.
| Temperature | 23-27°C |
|---|---|
| pH | 5.0-7.0 |
| Hardness | Soft to low-moderate hardness preferred |
| Nitrate control | Keep low with regular maintenance and sensible feeding |
| Acclimation | Slow acclimation is recommended, especially into softer or more acidic water |
Do not chase sudden pH changes. If your aquarium is already mature, clean and on the softer side, stability is normally more valuable than constant adjustment. Avoid adding this fish to a new tank that is still swinging biologically.
| Single specimen | Works well in a quiet planted or botanical display |
|---|---|
| Pair | Often a good choice when the tank has several shaded retreats |
| Small group | Possible in a larger, structured aquarium with broken lines of sight |
| Multiple males | Give extra floor area, cover and visual barriers |
This is not a tight schooling tetra like Cardinal Tetra or Ember Tetra. It may hold position near the lower and middle levels, inspect caves or leaf edges, and spend time under cover. That behaviour is normal; the goal is to make it confident rather than forcing it into a busy community role.
| Best foods | Daphnia, cyclops, brine shrimp, mosquito larvae and other small frozen or live foods |
|---|---|
| Prepared foods | Quality micro pellets, fine granules and crushed soft foods |
| Feeding style | Small portions, watched carefully so faster fish do not take everything |
| Conditioning | Use varied small foods to bring out behaviour and body condition |
Its mouth and natural diet point toward small invertebrate foods. It can learn prepared foods, but varied frozen and live foods are helpful, especially after arrival. Feed in more than one spot if it is sharing with quicker surface or midwater fish.
Choose calm species that enjoy similar soft-water conditions and will not bully the Sailfin Tetra away from food. Good directions include pencilfish, hatchetfish, small Corydoras and peaceful tetras in planted or botanical aquariums.
Avoid boisterous barbs, large cichlids, fin nippers, very fast feeders and fish small enough to be viewed as prey. If the Sailfin Tetra starts hiding constantly, the issue is often light, cover, flow or competition rather than the fish itself.
| First-time offer | Use code WELCOME10 for 10% off your first eligible livestock order. |
|---|---|
| Delivery promise | Eligible livestock is covered by our Live Arrival Guarantee when the delivery and acclimation steps are followed. |
| On arrival | Dim the lights, acclimate slowly and offer tiny foods once the fish has settled. |
| Best first week | Keep the aquarium calm, avoid major maintenance shocks and watch that it feeds. |
When stock is available, livestock orders are packed carefully for live-animal courier delivery. Because this species is shy and soft-water leaning, a calm first week is important: low light, stable water and small foods help it settle properly.
Choose Sailfin Tetra if you want a rare, behaviour-led characin for a shaded planted or blackwater-style aquarium. It is a strong choice for aquarists who already enjoy subtle South American fish and can provide structure, mature filtration and calm tank mates. If your tank is bright, boisterous or full of fast-feeding fish, build the layout first or choose a bolder tetra instead.
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