Introduction
Hemigrammus hyanuary, commonly known as the january tetra, is a small South American characin native to the Amazon basin. The species is regularly found in the aquarium trade.
Who is it?
Morphology
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Average size4 cm
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Maximum size5 cm
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Longevity4 year
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Average size4 cm
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Maximum size5 cm
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Longevity4 year
How to recognize This fish ?
The body is elongated and moderately laterally compressed. The coloration features a silvery body with a bright yellow-green longitudinal stripe that varies in intensity depending on the angle of light. The belly displays iridescent and coppery reflections. A wide black spot extends from the middle of the caudal fin and tapers towards the caudal peduncle. The top of the caudal peduncle is adorned with a large round and very bright spot. The mouth is terminal and adapted for capturing small prey in open water. It reaches up to 4 cm in total length. Experimental studies report two color variations in the upper part of the eye in this species, one silvery and the other metallic green. Research indicates that this characteristic is of genetic origin.
Sexual dimorphism
As with most species belonging to the genus Hemigrammus, females are larger and have a rounded belly during the breeding season. There are no other noticeable differences between the two sexes.
Behaviour & Life cycle
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dietomnivorous with carnivorous tendency
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Sociabilityliving in shoals
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territorialNo
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Way of livingdiurnal
The species moves in schools of several hundred fish and coordinate their movements. The species is omnivorous with a tendency towards insectivory. Its diet consists of micro-crustaceans, worms, and insects that have fallen into the water. Feeding is supplemented by organic and plant residues suspended in the water. This tetra prefers calm waters rich in submerged roots and vegetation.
Reproduction
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Reproductionovipare qui pond en eau libre
Spawning takes place in open water and fertilization is external.
Harmless species
Hemigrammus hyanuary is harmless to humans.
Origin and distribution
Geographic distribution & Conservation
The species is found in the Amazon basin in tropical freshwater. It frequents floodplain lakes, including Lake Hyanuary near Manaus, which gave the species its name.
Conservation status of populations (IUCN)
What is its habitat?
Natural environment characteristics
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Temperature23 - 27 °C
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pH (acidity)6 - 7.5
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gh (hardness)5 - 15
Biotope presentation
The biotope includes water bodies and rivers with low currents in the Amazon basin, including areas of floodplain heavily influenced by the rainy season. The species inhabits areas near the shores where vegetation provides shelter and resources for micro-invertebrates. It occupies low-current areas where seasonal water level fluctuations shape the environment during the rainy season.
Main recommendations for fishkeeping
Deontology
In order to preserve wildlife, if you acquire this animal, it must not be released into the wild. See also, the Fishipedia charter.
Fishipedia supports the practice of responsible and environmentally friendly aquarium keeping. We encourage maintenance if it is motivated by a desire to understand the biological functioning of living things and if it is done with respect for animal life.
We believe that aquaristics is an opening to the discovery of aquatic environments, especially freshwater, and that this knowledge is necessary to better protect and respect these environments. Logically, we refute the compulsive purchase of animals that would not find a sufficient and / or adapted place in the host aquarium.
Our recommendations
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Min volume100 liters
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Population min10
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Temperature23 - 27 °C
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pH (acidity)6 - 7.5
Characteristics
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Difficulty breedingmoderate
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Robustnesstolerant
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Behaviourpeaceful
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Availabilityrare
Recommended equipment from our partners
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Aquarium
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Filtration
General reminders
It is strongly advised to read the complete dedicated file and to get information on the feedbacks of maintenance of the envisaged animal, this to avoid any potential conflict whose end result is generally the death of the individual (or the other inhabitants). It is important not to overload your aquarium to limit pollution. This will make maintenance easier.
In nature, animals are subject to weather conditions and live in waters with variable characteristics. The recommendations offered by our team for aquarium maintenance are a guidance and cannot be assimilated to scientific datas.
General reminder on maintenance datas
Le démarrage d'un aquarium est une partie primordiale pour l'équilibre et le bien-être des poissons. Lorsque l'on met en eau un aquarium, l'eau passe naturellement par un cycle biologique : le cycle de l'azote. Celui-ci dure environ trois semaines. Tous les 2 jours, nous vous conseillons de tester votre eau jusqu'à ce que le taux de nitrite soit à zéro pendant plusieurs jours d'affilée.
Pour accélérer ce cycle, vous pouvez utiliser un activateur de bactéries comme JBL Denitrol. Cette solution riche en bactéries vivantes et enzymes permet une mise en place rapide du cycle de l'azote. Les poissons peuvent alors être introduits plus rapidement.
Il est important de tester l'eau de son aquarium régulièrement pour maintenir un environnement sain pour les poissons et les autres habitants. Les tests d'eau permettent de mesurer les niveaux de différents paramètres tels que le pH, la dureté totale, ainsi que les taux de nitrates, de nitrites et d'ammoniaque.
Pour réaliser ces tests, vous pouvez utiliser des produits d'analyse spécialisés tels que JBL ProScan qui permet de réaliser un diagnostic de l'eau directement via un smartphone. Il existe également des coffrets de tests plus classiques de bandelettes, comme JBL PROAQUATEST.
En cas d’usage de l’eau du robinet, vous pouvez utiliser un conditionneur d’eau de type Biotopol de JBL pour éliminer les substances nocives comme le chlore, le cuivre, le plomb et le zinc. Une eau trop dure ou trop calcaire peut être inadaptée à de nombreuses espèces tropicales d’eau douce. Si nécessaire, vous pouvez la couper avec de l’eau osmosée ou de pluie filtrée afin d’obtenir une dureté plus adaptée aux besoins de vos poissons et de vos plantes. Les conditionneurs d'eau garantissent une meilleure santé aux poissons et une meilleure croissance des plantes.
Chlorine and chloramine are dangerous for the health of animals. Used to disinfect water, these agents are present in significant quantities in tap water. We recommend using an anti-chlorine agent every time you change the water. In addition to chlorine, treatments and medicines sold for aquarium use sometimes contain dangerous heavy metals in high doses.
Specific needs for the january tetra
The january tetra is a species which lives naturally at a temperature between 23 °C and 27 °C. Nitrate levels should remain below 50mg/L. To keep the water clean and unpolluted, plan on changing 20% to 30% of the water volume each month.
The breeding of this species is accessible on condition of being well informed about its needs in aquarium . Any cohabitants must be chosen with care to avoid the loss of animals.
This species is very rare in the aquarium trade. Instead, it is maintained by knowledgeable aquarists who own and breed individuals from wild origin strains. If you want to get this species, we advise you to contact specialized clubs. }Specimens from long time breeding are a bit easier to breed but you have to respect the particular water parameters.
Cohabitation & Environment
Being a living in shoals fish, it is advisable to install at least 10 individuals in an aquarium of 100 liters minimum. Group maintenance is a prerequisite to ensure their well-being. Lonely individuals tend to quickly become stressed and become especially susceptible to disease. Although sometimes certain groups can "merge", mixing several gregarious species living in the same zone of life is not recommended if the volume is not consequent. The january tetra needs a large living space, therefore it is advisable to keep it in an aquarium with a frontage of at least 80 cm.
The january tetra is a peaceful species that generally does not exhibit behavioral problems in a community aquarium.
It should be noticed that this species should not be kept with large crustaceans or fish, as it would become a prey of choice. Smaller species should preferably be inserted in the aquarium some time before the larger ones. Moreover, if you want to breed it, it is better to put them in a specific aquarium.The species enjoys a particularly vegetation-rich environment. The addition of plants will provide many useful hiding places for resting. These areas are also conducive to possible breeding in the aquarium. Floating plants such as Salvinia can be added to recreate the subdued atmosphere characteristic of its living conditions in the wild.
Tips for feeding
The january tetra is omnivorous with carnivorous tendency.
This species can eat dry food (flakes, pellets), fresh food and frozen food. To avoid deficiencies, it is recommended to vary the types of food.
Feed animals in moderation to maintain good water quality. Meals should be eaten within 2–3 minutes, served in several small portions rather than a single large ration.
Uneaten food quickly decomposes, releasing ammonia, nitrites, and nitrates, which disturb the aquarium’s biological balance.
Make sure each species can access food properly, slower or bottom-dwelling individuals may require targeted feeding.Food recommendations from our partner JBL - Products PRONOVO
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Granules
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Flakes
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Sticks
Reproduction protocol
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Maintenance difficultyhard
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egg-laying protectionNo
Reproduction of this species in an aquarium is considered hard. Ideally, it takes place at a temperature of around 26 ° C for a pH of 6 .
Hybridization risks
In general, it is advised not to mix several species of the same genus or different varieties of the same species, to avoid the risks of hybridization.
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To go further
Sources & Contributions
Participation & Validation
The Fishipedia team and specialist contributors are committed to providing high-quality content. However, although the information comes from scientific sources or testimonials from specialists, the cards may contain inaccuracies.
Benoit Chartrer
Translation
Translation done with the valuable contribution of our translators, who make this information available to a wider audience. We sincerely thank them for their commitment.
Benoit Chartrer
Scientific partners
Species of the same family
Same genus