Hyphessobrycon sweglesi is a species of tetra that lives in the Orinoco River drainage basin in South America.

[5] The species' appearance is very similar to Hyphessobrycon megalopterus (black phantom tetra).

Aquarists keep this fish in water ranging from 20 to 23 °C (68 to 73 °F) that is soft (50–100mg/L) and acidic (pH 6.5).

[4] The H. sweglesi is reported to be very sensitive to water chemistry, which affects the fish's coloration.

Aquarists put dark substrate in the spawning tank to protect the eggs from light.