No established common name

Where they come from

Jupiaba potaroensis is a small characin from the Potaro-Essequibo system in Guyana. Think clear to tea-stained forest streams with leaf litter, roots, and a bit of current. Water there is soft, slightly acidic, and full of tannins from all the plant material.

Setting up their tank

They stay small, but they are quick and like room to school. I would not drop a group into anything shorter than a 30-inch tank. A 20-long or 29-gallon works well for 10-15 fish.

• Substrate: fine sand or small gravel. Darker substrate helps them color up.
• Hardscape: driftwood branches, roots, and leaf litter (catappa, oak). Add some botanicals for tannins.
• Plants: floating cover (Salvinia, frogbit) to cut the light, plus stems or crypts around the edges.
• Filtration: a canister or HOB with a spray bar for gentle to moderate flow. Add a prefilter sponge to protect small fish.
• Lighting: on the dimmer side. They relax and show better color with shade and tannins.
• Lid: tight-fitting. These guys can and will jump during spooks or water changes.

What to feed them

They are micro-predators in the wild, picking at tiny invertebrates. In the tank they do best with small foods and frequent feedings.

• Daily staple: quality fine flakes or 0.5-1 mm micro pellets.
• Meaty rotation: frozen or live baby brine shrimp, daphnia, cyclops, grindal worms.
• Occasional treats: mosquito larvae, micro worms. Go easy on fatty worms to avoid bloat.
• For shy new imports: live foods first, then mix in prepared foods once they are eating confidently.

How they behave and who they get along with

In a group they are busy midwater swimmers with quick darting moves. Keep at least 8, but 12+ looks and works better. Without numbers they get skittish and hug corners.

• Good tankmates: other small, peaceful characins, pencilfish, hatchetfish, Corydoras, small Apistogramma that are not hyper-territorial.
• Use caution with: boisterous barbs or danios that outcompete at feeding time.
• Avoid: large cichlids, nippy fish that target fins, and slow long-finned fish that hate current.

Breeding tips

They are egg scatterers and will spawn in soft, acidic water if well fed. Adults will eat eggs, so use a separate setup.

• Conditioning: a week or two of heavy live/frozen foods.
• Spawning tank: 10-15 gallons, dim, pH 5.5-6.5, GH 1-3, temp around 78-80 F. Add a mesh or marbles on the bottom, plus fine-leaved plants or spawning mops.
• Method: 1-2 females with 2-3 males in the evening. They usually scatter eggs at first light.
• After eggs: pull adults right away. Keep the tank shaded; many characin eggs are light sensitive.
• Raising fry: hatch in 24-36 hours, free swimming by day 3-4. Start with infusoria or green water, then microworms/rotifers, then baby brine shrimp once they can take it.
• Maintenance: gentle sponge filter, tannins help keep fungus down, small daily water changes.

Common problems to watch for

• Jumping during spooks or maintenance. Keep the lid tight and cover gaps.
• Stress from hard, alkaline water. They fade out and hide. Use RO mix and add botanicals.
• Ich after shipping or sudden temp swings. They dislike harsh meds; raise temp slightly and use half-dose formalin-malachite or salt with good aeration.
• Internal parasites in wild-caught fish. Quarantine and deworm with a proven med before adding to your display.
• Low oxygen in warm tanks. Keep surface agitation up, especially in summer.
• Overbright lighting leading to washed-out color and nervous behavior. Floaters and wood help a lot.