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Maximum size : 4 cm

Costello Tetra - Hemigrammus hyanuary : Complete Fish Profile & Care Guide

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The Costello Tetra (Hyphessobrycon costai) is a fascinating and striking species that, unfortunately, is becoming increasingly rare in the aquarium hobby. It is often confused with the common Head and Tail Light Tetra due to its similar appearance, but upon closer inspection, its elongated body sets it apart. These peaceful and docile fish are best kept in a community tank with other species of similar size and temperament. They may become intimidated and stressed by larger or more boisterous tankmates, so it is essential to select tankmates carefully. As a naturally shoaling species, they will thrive when kept in groups of six or more, allowing them to feel more secure and show their best behaviour. The Costello Tetra has a distinctive pale silvery-olive body featuring a striking yellowish-green lateral stripe that runs from its gills to its caudal peduncle. In addition, a black spot is present on the caudal peduncle, and its caudal fin is forked, with translucent fins that possess a delicate yellow tint. Overall, these unique characteristics make the Costello Tetra an eye-catching and desirable addition to any aquarium.

Costello Tetra Photos

Sexual Dimorphism

Distinguishing male from female Costello Tetras is a straightforward process. Males are generally smaller and slimmer than their female counterparts and possess a small hook on their anal fin that is absent in females. Conversely, females are larger and rounder in body shape and exhibit less vibrant colouration than males.

Quick Facts

Scientific NameHemigrammus hyanuary
Year Described1918
Other NamesJanuary Tetra
OriginsPeru Brazil
Max Size4 cm
Aquarium LevelMiddle - Top
DifficultyBeginner - Intermediate
Best kept asGroups 6+
Lifespan3 - 5 years

Water Parameters

Water TypeFreshwater
PH6.0 - 7.0
GH2 - 15
74 - 80
23.3 - 26.7

Natural habitat

The Costello Tetras are a mesmerizing species of freshwater fish native to South America's Central and Upper Amazon Basins. Found in regions spanning from Lake Hyanuary near Manaus in Brazil to the waterways of Peru, these Tetras thrive in slow-moving rivers, streams, and floodplain lakes adorned with dense vegetation. In their natural habitat, these fish inhabit soft and acidic brown-coloured water stained with tannins, which are a byproduct of decaying plant matter. The tannins create an enchanting, almost mystical aquatic environment that is visually stunning to behold.

How to breed the Costello Tetra

Breeding Costello Tetras can be a straightforward process, and in a well-planted aquarium, you may occasionally see small numbers of fry without any intervention. However, setting up a separate breeding tank is recommended if you want to raise a larger quantity of fry. The breeding tank should have soft, acidic water, and the temperature should be at the high end of the recommended range. Clumps of Java moss or fine-leaved plants should be added to give the fish a place to scatter their eggs, and gentle filtration should be provided with a small air-driven sponge filter. It's best not to have lighting in the tank as eggs and fry are light-sensitive. Before spawning, the Tetras should be conditioned on small meaty live or frozen foods. Males and females should be introduced into the breeding tank in the evening, and spawning should occur when sunlight hits the tank the next morning. After spawning, the parents should be removed immediately as they will consume the eggs. Fine mesh can be used on the bottom of the tank to allow the eggs to fall through safely away from the adult fish. The eggs will hatch within 24-36 hours, and the fry should become free-swimming within 72-96 hours. To protect the sensitive young fry from bright light, the tank should be kept in darkness once the eggs have been scattered. Infusoria should be fed initially, followed by microworm and baby brine shrimp as the fry develops and consume their yolk sacs.

Diet & feeding

A varied diet is essential to keep the Costello Tetra in the best condition possible. While they are not particularly choosy regarding food, offering them a mix of high-quality dried foods such as pellets, granules, and flakes alongside small live and frozen foods like daphnia, mosquito larvae, and brine shrimp are highly recommended. A well-balanced diet incorporating plant and animal-based foods will help ensure your fish remain healthy and vibrant.

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