Aquarium - Guide for aquarists

January Tetra (Latin Hemigrammus Hyanuary)

January Tetra - Green Neon
Basic info

January Tetra (known also as  Green Neon) Hemigrammus hyanuary

Wikipedia/Thomas Grafe, Schonheide (Thomnight)/CC BY-SA 2.0

Species January Tetra (known also as Green Neon)
Latin Name Hemigrammus Hyanuary
Family characidae
Origin South America
Lenght 4 cm
Temperature 23 - 27 [°C]
pH6,0 - 7,5
Water Hardnesssoft - medium hard
Aquarium Size 80 [L]
Food live, frozen, dry highly fragmented

January Tetra (known also as Green Neon)


This freshwater species in nature lives in tropical tributaries of Amazon River and tributaries of Brazil or Peru lakes.

Body description

Body of the fish is elongated and fusiform. Colour of the body is silvery-olive. There is opalescent yellow-green stripe along the lateral line. There is also dark spot with opalescent gold border on the base of the caudal fin. Upper part of the iris is gold. Female is thicker and larger than male. Male's anal fin has visible hooked shape.

Characteristics and temperament

This is quiet, peaceful and shoal species. It is stressed and shy in too small group. The fish is very active and undemanding.

Aquarium decoration

These fish may be kept in Dutch style aquascape or general aquarium – with lot of plants. The general tank should include dark substrate, dimmed light, floating plants, hiding-places among roots, caves, space to free swimming. Water should be clean and oxygen-rich. We need an effective filtration system (we may add peat). A partial water changes should be systematic done. This species is sensitive to water quality and diseases.


This is oviparous species. We should reproduce these fish in a separate aquarium. This breeding tank should include soft water, slightly acidic pH and somewhat wormer water temperature, dimmed light or without light, fine-leaved floating plants or fish hatchery, gentle but effective filtration system. We should separate male and female groups of the fish before the spawning and we should feed their with plenty of live food. We transfer to the breeding tank the most colourful male and the thickest female in the evening. The fish should spawn next day in the afternoon or evening, after intense courtships. Female spreads 100-200 eggs which fall to the bottom. We must immediately remove the parents after the spawning. The eggs hatch after 1 day. The fry starts swimming and feeding 5 days later. The roe and fry are sensitive on light and water quality.

We use cookies on this website. If you continue browsing you agree to use cookies. For more info read privacy policy.