The highlight colour fish, also known as the neon tetra, is one of the most popular freshwater aquarium fish species. Its vibrant colours and active schooling behaviour make it a favourite among hobbyists.
The neon tetra (Paracheirodon innesi) is a small, brightly-coloured fish that originates from the Amazon River basin in South America. It is characterized by an elongated body with an adipose fin, a blue-green stripe that runs horizontally along each side, and an orange-red colouration on the head and tail.
Neon tetras typically grow to be 1-1.5 inches (2.5-4 cm) long and have a life span of 5-10 years with proper care. They are schooling fish that prefer to be kept in groups of 6 or more. In the wild, they inhabit slow-moving, blackwater streams and flooded forests.
The neon tetra was first imported to Germany in the 1930s and entered the aquarium trade shortly after. Its glowing colours and peaceful temperament quickly made it a coveted species. Today, it remains one of the most popular freshwater fish for community aquariums around the world. Millions are bred in captivity annually to supply the demand.
Appearance and Colours
The most distinctive feature of the neon tetra is its vivid colouration. Here is a description of its key colours and markings:
- Blue-green stripe – Runs horizontally along each side of the body. This iridescent stripe seems to ‘glow’ and is how the neon tetra got its name.
- Orange-red tail – The caudal and anal fins are coloured bright orange-red.
- Silvery belly – The underside of the neon tetra has a silvery sheen.
- Blue nose – Their snout and forehead area often shows a blue tint.
- Transparent fins – The dorsal and pectoral fins are mostly clear/transparent.
Males and females look virtually identical. The only noticeable difference is that females tend to display a more rounded belly, especially when carrying eggs.
The neon tetra’s colours originate from special pigment cells called chromatophores that contain light-reflecting crystals. When illuminated, these cells show an iridescent, metallic shine. This makes the colours seem to glow under aquarium lighting.
Natural Habitat and Origin
In the wild, the neon tetra inhabits soft, acidic blackwater rivers, streams, and flooded forests across parts of Brazil, Peru, and Colombia in South America.
Some key details about its natural habitat:
- Water pH – Very low, acidic at 4.0 to 6.0 pH
- Temperature – Approximately 21-30°C / 70-86°F
- Decor – Abundant leaf litter, submerged branches, roots and vegetation
- Substrate – Clay, sand, silt
- Lighting – Shaded, tannin-stained water
These dark, tannin-rich waters are inhospitable to most aquatic species. But the neon tetra has adapted to the conditions through evolutionary specializations. This includes a tolerance for low oxygen levels.
In the Amazon basin, neon tetras form large schools consisting of hundreds or even thousands of individuals. Schooling provides protection from predators. Their bright colours likely help differentiate species members within the diffuse, tea-coloured waters.
Neon Tetra Care
Caring for neon tetras requires re-creating some of the natural environmental conditions they are adapted to. Here are some key care guidelines:
Neon tetras are active swimmers and should be kept in at least a 10 gallon aquarium. Provide around 2 gallons of space per fish. A long tank is better than tall for this species.
Neon tetras do best in soft, acidic water:
- pH: 5.5 to 7.0
- Hardness: 1 to 5 dGH
- Temperature: 22 to 28°C / 72 to 82°F
Use peat, driftwood, oak leaves, or specialty products like Black Water Extract to help recreate “blackwater” conditions.
Decorations and Plants
Planted tanks with lots of hiding spots suit neon tetras. Use leaf litter, branches, aquatic plants like Amazon swords and Elodea, and floating plants. Keep the tank dimly lit. Dark substrates also help bring out their colours.
Neon tetras are very peaceful and mix well with small, non-aggressive species that prefer similar water conditions. Some good tankmates include:
- Cardinal Tetra
- Ember Tetra
- Endler’s Livebearer
- Corydoras Catfish
Avoid pairing them with large or nippy fish that may attack them.
In nature neon tetras feed on tiny insects, worms, crustaceans and other zooplankton. In the aquarium they will accept a variety of foods including:
- Flake foods
- Micro pellets
- Live foods like brine shrimp, daphnia, and mosquito larvae
- Frozen foods like bloodworms
- Golden Neon Tetra – Has an orange-yellow stripe instead of blue-green
- Ruby Neon Tetra – Displays bright, ruby red colours instead of orange
- Sunset Neon Tetra – Exhibits a mix of yellows and oranges
Feed them 2-3 small meals daily and vary their diet for the best nutrition. Take care not overfeed.
Breeding Neon Tetras
While neon tetras are easy fish to care for, breeding them can be challenging. Here’s a quick overview of how to breed neon tetras:
Males tend to be slimmer with more prominent blue and red colouration. Females display a robust abdomen, especially when carrying eggs.
Use a separate breeding tank with soft, acidic water around 26°C/79°F. Place a breeding mop or mesh for the fish to spawn on. Well-conditioned adults will spawn readily. They scatter eggs and display no parental care.
Hatching the Eggs
Eggs hatch in roughly 24 hours. Remove parents after spawning is complete. Keep water clean and circulated around the eggs. Hatching rates are low, even in ideal conditions.
Raising the Fry
Newly hatched fry are tiny (Variants and Genetics
Through selective breeding a number of unique neon tetra colour morphs have been developed for the aquarium trade. Some popular varieties include:
These variants arose from genetic mutations. By selectively breeding fish exhibiting the colour traits, aquarists developed true-breeding lines. However, many color morphs are less hardy than the natural form.
There are also “Tetra” fish marketed with names like Red Neon Tetra, Blue Neon Tetra, etc. Most of these are not actually Neon Tetras but close relatives or hybrids. True P. innesi can be identified by the specific blue-green stripe pattern.
The neon tetra is categorized as Least Concern on the IUCN Red List. It remains widespread across its native range. Due to extensive harvesting for the aquarium trade, some local populations have been negatively impacted. But most rivers maintain healthy numbers.
For conservation, focus is placed on sustainable harvesting and aquatic habitat protection in South America. Captive breeding programs also help reduce collection pressures. The species’ role as a popular aquarium fish ensures continued demand.
In summary, the highlight colour fish known as the neon tetra continues to be one of the most iconic and recognizable freshwater species kept in home aquariums. Its glowing stripes set it apart from other fish. Neon tetras thrive under the right water conditions and tank setup. While breeding can prove challenging, their availability from commercial breeders makes them an easy fish to acquire. With proper care, these tiny Amazonian beauties will brighten up any home aquarium.
The neon tetra’s vivid blue and red stripes make it instantly identifiable. Despite its small size, this Amazonian fish has had an outsized influence on the freshwater aquarium hobby. Its popularity stems from the neon tetra’s hardiness, active schooling behaviour, and of course its striking live colours that made it an instant hit after first being imported. Even with many new fish species entering the trade, the neon tetra remains an aquarist favourite, and will likely continue lighting up home aquariums for years to come. For those looking to add some glow and excitement to their tank, few fish can compete with the highlight colour beauty of the neon tetra.