Blue Tetra (coeruleus) Care Guide
Hemigrammus coeruleus is a Rio Negro characin with a blue-green sheen and dark caudal markings, kept as a peaceful blackwater schooling fish.
Compiled by Aquairi from published sources · Published · Updated
Overview
Hemigrammus coeruleus is a characin from the Rio Negro region with a subtle blue-green sheen and dark caudal markings. It is kept as a peaceful schooling fish that favours blackwater conditions.
Taxonomy
- Family: Characidae (order Characiformes)
- Genus: Hemigrammus
- Scientific name: Hemigrammus coeruleus
Habitat
FishBase records the species from the Solimoes and lower Negro River basins in South America, as a benthopelagic freshwater fish of tropical waters.
Tank requirements
- Minimum tank volume: 80 L
- Temperature: 24-28 °C
- pH: 4.5-6.5
- GH: 1-6 °dGH
- Maximum size: about 5.8 cm TL (FishBase)
- School size: 6 or more individuals
- Lifespan: 3-5 years
Diet
The species is omnivorous and accepts small dried, frozen and live foods in the aquarium, fed twice daily.
Compatibility
It is a peaceful mid-water schooler best suited to soft, acidic blackwater tanks. Suitable companions include Cardinal tetras and dwarf cichlids such as Apistogramma; hard-water species should be avoided.
Conservation status
IUCN Red List: Least Concern (assessed 2021).
Blue Tetra (Hemigrammus coeruleus) Breeding Guide
Overview
Hemigrammus coeruleus Durbin, 1908, the blue tetra, is a freshwater benthopelagic characid recorded by FishBase from the Solimões and lower Negro River basins, reaching about 5.8 cm. FishBase lists no breeding details, and no whitelisted source documents a captive spawning, so the notes below combine the verified data with the egg-scattering pattern of the genus Hemigrammus.
Sexing
No species-specific sexing characters are recorded in the consulted sources. Across the genus Hemigrammus, mature females are generally rounder and fuller-bodied than the slimmer males when in condition.
Conditioning
FishBase classifies the species as freshwater, benthopelagic and tropical. In the absence of species data, the genus approach is to condition a maintained group on small live and frozen foods until females visibly fill with eggs.
Breeding Setup
Following the Hemigrammus pattern, a small dimly lit spawning tank with fine-leaved plants or a spawning mop, or a mesh base keeping eggs out of the adults' reach, with gentle air-driven sponge filtration, suits egg-scattering tetras. Species-specific spawning parameters for H. coeruleus are not on record.
Egg & Fry Care
In the genus, eggs and early fry are light-sensitive, adults give no parental care and eat their own spawn, eggs hatch within roughly 24-36 hours, and fry become free-swimming after a few days, taking infusoria-grade food before brine shrimp nauplii. No egg count or timing is confirmed for H. coeruleus itself.