Neon Tetra

Neon Tetras (Paracheirodon innesi) are among the most well-known and widely kept aquarium fish. Their striking “neon-like” colours make them a standout feature that even newcomers to fishkeeping notice immediately.

The iris of the neon tetra glows green-blue and its back is olive green

The neon tetra is one of the most well-known aquarium fish

Appearance: A Brilliant Eye-Catcher

With a size of about 3.5 to 4cm, the neon tetra is one of the smaller ornamental fish. Its iris shines in green-blue while its back is olive green. The underside of its belly ranges from white to silver in colour.

At first glance, the neon tetra stands out with its turquoise-blue horizontal stripe that extends from its eyes to its adipose fin, located between the dorsal and tail fins.

Difference from the Cardinal Tetra

The Cardinal Tetra shares a similar feature. However, the two fish can be distinguished by the red area below the blue stripe. In the neon tetra, the red area starts from the ventral fin and stretches to the tail fin. In the cardinal tetra, this red area covers the entire lower half of the body.

The neon tetra is one of the smaller ornamental fish © Otto Durst / stock.adobe.com
The red colour of the Neon Tetra does not extend all the way down its belly, unlike the Cardinal Tetra

Sexual Dimorphism: Female or Male?

Determining the sex of neon tetras is not always straightforward. These two external traits can help you:

  • Females are plumper than males
  • Females usually have a slight kink in their blue stripe

Behaviour: Vivid Colours as a Defence Mechanism

The neon tetra’s bright colours might suggest it’s an easy target. However, when swimming in a shoal, the reflections confuse predators, making it more challenging to catch them. The fish do not glow themselves but reflect incoming light.

You can observe this well in an aquarium. In the morning, when the lights come on, neon tetras often do not show their full colours immediately. As the light increases, their vibrant colours become more pronounced.

The neon tetra's colours become brighter and more vibrant as more light shines on them © inubi / stock.adobe.com
The neon tetra confuse the attacker in the swarm with reflection

Care: How to Set Up the Perfect Aquarium for Neon Tetras

A minimum of a 60-litre aquarium is recommended for neon tetras. Generally, the bigger, the better.

The ideal water temperature for neon tetras is between 20 and 26°C, akin to temperatures in their native Peru. The water should also have a pH of 5.0 to 6.8 and a hardness of 2 to 10 °dH.

Plants and Substrate

Neon tetras enjoy swimming plenty. Partially densely planting the aquarium and ensuring enough swimming space is crucial.

Fine-leaved water plants and floating plants to dim the light work best for aquarium planting. Additionally, a dark substrate and dim lighting conditions are advisable.

Group Size

This freshwater fish is a shoaling species, preferring groups of at least ten fish. However, neon tetras are not typical shoaling fish.

With adequate visual contact, they don’t swim in a tight shoal. Instead, tetras spread throughout the aquarium and only sometimes swim closely together.

Compatibility

Neon tetras are generally very peaceful, making them suitable companions for various ornamental fish. However, avoid fish species that might see neon tetras as prey. All fish species should have similar care requirements.

Suitable companions include guppies, platys, catfish and other tetra.

Nutrition: What Fish Food is Suitable for Neon Tetras?

You can offer neon tetras all live and frozen food found in their natural habitat, such as artemia, mosquito larvae and daphnia.

Flake food and pellet food are also suitable. Ensure a varied diet to maintain a species-appropriate diet.

Breeding: Reproducing Neon Tetras in the Aquarium

With a bit of knowledge, breeding neon tetras in an aquarium is feasible. A breeding aquarium with about 10l of soft water is recommended.

Preparations

As neon tetras are free spawners and deposit their eggs in dense fine-leaved plants, you should decorate the tank with Java moss, Myriophyllum or green filter wool.

Place a pair in the breeding aquarium, and they will spawn at about 24 to 25°C. To prevent fungal growth on the eggs, dim the aquarium and add an Indian almond leaf.

After Spawning

After spawning, remove the parents from the tank as they might eat the eggs. Wait about a week for the fry to hatch. Feed them with ciliate or infusoria until they are big enough for the main tank.

Health: How Robust Are Neon Tetras?

Neon tetras are generally quite resilient aquarium fish with appropriate care and feeding. However, a fish disease is typical among neon tetras and should be researched before purchase.

Neon Disease

Although neon disease can appear in other tetra species and barbs, it is primarily associated with neon fish. Parasites (microsporidia, Pleistophora hyphessobryconis) that spread through infected food or fish cause it.

You can identify the disease by white patches that cause your fish’s shine to fade gradually. Another sign is the curvature of the affected fish’s spine.

Unfortunately, the disease is currently incurable. Therefore, it’s crucial to remove affected fish early and place them in a quarantine tank to prevent spreading.

Lifespan of Neon Tetras

In the wild, they typically live for 1 to 2.5 years, but they can live for about 6 to 10 years in an aquarium.

Origin: A Beauty from Peru’s Depths

Neon tetras originate from South America, specifically the clear water streams of Peru’s rainforest. They inhabit the upper Amazon Basin (from Iquitos to São Paulo de Olivenca) and the Rio Putumayo and Rio Purus basins. In general, they dwell in dark, shaded waters with a dark substrate.

Costs: How Much Does a Neon Tetra Cost?

Neon tetras are easy to care for, making them especially appealing to beginners. They are also relatively inexpensive, with an individual cost as low as £1. You can easily purchase a shoal from a specialised shop without significant financial commitment.

Don’t forget the ongoing costs for the aquarium, as well as veterinary checks or treatments.

Neon Tetra Fact Sheet

Names:Neon or Neon Fish; Latin: Paracheirodon innesi
Body Length:3.5-4cm
Care Requirements:In a shoal; min. ten fish, preferably more
Compatibility:Possible with other peaceful fish
Aquarium:Freshwater, min. 60L
Water Temperature:20-26°C
Water Hardness:pH: 5.0-6.8
Food:Dry, frozen, live food
Difficulty Level:Easy
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