Yellowfin Chalceus (4-4.5”)

Scientific Name

Chalceus erythrurus

Maximum Size and Lifespan

The Yellowfin Chalceus can reach a maximum size of around  (8 inches) in length
With good maintenance and a proper diet, their lifespan averages 7–8 years, sometimes longer in large, stable aquaria.

Recommended Aquarium Size, Water Changes, and Water Parameters

This is an active, fast-swimming species that requires plenty of open space and clean, well-oxygenated water.

• Minimum aquarium size: 75 gallons (210 L) for a single specimen or small group; larger tanks preferred for multiple individuals/community setup.

• Temperature: 24–28 °C (75–82 °F)

• pH: 6.5–7.5

• Hardness: Soft to moderately hard water

• Water movement: Moderate to strong flow with excellent aeration

• Water change schedule: 25–40 % weekly to maintain pristine conditions and stable parameters

• Other care notes:

  • A tight-fitting lid is essential, as this fish is a powerful jumper when startled.

  • Use dim or diffused lighting with open swimming space and areas of driftwood or plants around the edges.

  • Maintain stable water conditions — Yellowfin Chalceus are sensitive to ammonia and nitrite spikes.

Tankmates

Yellowfin Chalceus are energetic, upper- to mid-level swimmers. They can be nervous or jumpy when kept alone, so they often do better in small groups of their own kind (3–5 individuals) if the tank is large enough.

Suitable tankmates:

• Medium to large peaceful cichlids (e.g., severums, geophagus)

• Large tetras and characins that are too big to be swallowed

• Robust catfish such as doradids, plecos, or synodontis

• Silver dollars and other fast-swimming, non-aggressive species

Avoid:

• Small tetras, guppies, or anything that fits in their mouth

• Very aggressive cichlids or territorial species that might harass them

• Shy, slow-moving fish easily stressed by active tankmates

Diet

Yellowfin Chalceus are carnivorous micropredators. In the wild they feed on insects, crustaceans, and small fish near the water’s surface.

In captivity, they readily accept:

• Floating carnivore pellets or sticks

• Frozen bloodworms, brine shrimp, krill, and chopped shrimp/tilapia
  

Feed small amounts once or twice daily, ensuring no uneaten food remains to foul the water.

Natural Environment

The species is native to northern South America, occurring in the Amazon and Orinoco River basins and surrounding tributaries.
They inhabit clear and moderately turbid rivers with good oxygenation and moderate current. Yellowfin Chalceus are surface-dwelling fish, often seen near the top of the water column, where they hunt insects and small prey that fall into the river.
In nature, they are found singly or in loose schools and are wary, quick to flee from disturbance.

Breeding

Captive breeding of Chalceus erythrurus is rare and poorly documented. They are believed to be egg scatterers, releasing eggs among floating vegetation or open water without parental care.
There are no confirmed reports of successful home aquarium breeding; most specimens are wild-caught. Controlled breeding in large, specialized facilities might be possible but has not been standardized.

Overview

The Yellowfin Chalceus is a striking, golden-bodied characin with red or yellow fins and an energetic personality. Best suited for experienced aquarists, it thrives in large, clean, well-covered aquaria with stable water and good current. While peaceful toward similarly sized fish, it will eat anything small enough to fit in its mouth.
Although breeding remains unachieved in captivity, this species is an excellent showcase fish when properly housed and maintained.