The first neon tetra was imported to the states in 1936 by ichthyologist Dr. George S. Myers. Over 80 years later, roughly 1.8 million neon tetras are imported to the states on an average month, making neon tetras an estimated $2.1 million market per year. No doubt, it’s one of the most popular fish in the hobby.
I wonder if Dr. Myers ever imagined the small, colorful, peaceful fish from the Amazon and Orinoco Basins would be so popular. Maybe he did because, for most, neon tetras check a lot of boxes. They’re easy to house, active, colorful, easy to feed, and are tolerant to a wide range of water and temperature parameters.
There is one box they no longer check, however; hardiness. Although most neon tetras are hardy once established in a mature tank, the first few weeks of them being in their new home can be tough. Even after being established, any changes to their water chemistry, temperature, or tank can stress them to the point of illness. Making matters worse for most beginner hobbyists, they are shoaling fish that need to be kept in a group of at least six to be happy – but I’d recommend 10 or more – which most new fish owners simply aren’t told.
Neons are particularly susceptible to neon tetra disease (NTD) and bacterial diseases and are often shipped in medicated water from fish farms to prevent massive casualties. There is mixed information about whether medication lowers fish’s immune systems, but even if not, the stress of transportation surely will. Then they sit on a shop floor, usually in sparsely planted tanks under bright lights where they stress even more, and this surely lowers their immune system. Combined with their mass-farmed status, they’re much weaker fish than they were when Myers imported them so long ago.
But if you insist on keeping a shoal of neon tetras, we’ll tell you everything you need to know.
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Are neon tetras good community fish?
For the average community tank, no, not at all, no. A well-researched one, maybe. But only if you know how to spot a healthy fish in the store, cycle a tank, and properly quarantine and introduce new fish – otherwise, again, no.
How can I tell the difference between a neon tetra, green neon tetra, and cardinal tetra?
Neon tetras, quite simply, have less color than cardinal tetras. On cardinals, the red line extends entirely to the head while in neons it stops about halfway through the body. Similarly, the blue line on neon tetras is narrower than the blue line on the cardinal. Differentiating the neon from the green neon is slightly trickier, but not by much. Green cardinals possess a greener line (versus bluer in neon tetra) that extends only to the adipose-fin (the small fin between the cadual and the dorsal fin. Neons also have more red than green neons.
Are there any other breeds of neon tetras?
Fish don’t particularly come in “breeds”, just species, sub-species and variants (“flavors”, if you will.) For neons, both man-made and natural variations can be found for sale. Almost all, however, come with more problems than the standard neon – which already has a host of issues. These include albino, gold, short bodied, long fin, and diamond. There is also a platinum (sometimes called gold) natural variant, but it’s coloring is thought to be caused by a parasite.
Neon Tetra Classification
IUCN Status: Not listed
Class: Actinopterygii are ray-finned fishes, which is a subcategory of boney fishes. These fish are characterized by the bony structures that support their webbed fins. This group makes up nearly half of all living vertebrates.
Order: Characiformes are a subgroup of ray-finned fishes including characins and 17 other recognized families.
Family: Characidae is a family belonging to characiformes that hail from tropical and subtropical waters. Although there is some scientific debate surrounding the preferred name for this family, “characids” is preferred by scientists.
Genus: Paracheirodon, all species in this genus are native to the neotropic ecozone in the Orinoco and Amazon river Basins. Paracheirodons reach maximum overall length between 0.98” – 1.97” (2.5 to 5 cm), are of elongated tetra shapes, and share a distinctive iridescent blue lateral line.
All of the fish in this genus are shoaling species that scatter their eggs and exhibit no parental care, often eating their eggs or fry in captivity. There are currently three recognized species in the Paracheirodons genus; the neon tetra, cardinal tetra, and green neon tetra.
Scientific name: Paracheirodon Innesi
What Does Paracheirodon Innesi Mean?
Para means “related to” and Cheirodon is a genus of characins from South America that Paracheirodons are related to.
Innesi comes from Wiliiam T. Innes who was an American aquarist, author, photographer, printer, and publisher. Innes wrote dozens of influential books and articles about fish keeping while the hobby was still relatively new. Without Innes – and the neon tetra – we likely wouldn’t have the hobby we know today.
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Natural Habitat & Distribution
The full range of the neon tetra in the wild is unknown. We do, however, know it occurs in the Orinoco and Amazon river basins, the lower Putumayo river, and rio Purus. However, some reports claim that they can also be found in the Río Ucayali drainage, Río Marañon, rio Japurá in Brazli (or Río Caquetá in Colombia), rio Javary, and the ríos Curaray and Mazán.
At their tiny stature, you can imagine neon tetras aren’t well-suited for raging rapids. Instead, they prefer to hang around in black water forest rivers and tributaries with slow flow. The water is often stained a dark tea color from the fallen leaves and branches. You can occasionally find plants in these areas, but with low pH and low light penetration caused by the humic acids, most plants don’t grow well.
If dark water isn’t your thing, some neon tetras have been caught in white water areas, however, there isn’t much information available on the location of those collection sites or how often this occurs in the wild.
Difficulty: Can be challenging
Size: 1.5″ (4 cm)
Lifespan: 5 – 8 years
Tank Size: 10 gallons (40 liters)
Diet: Omnivore – will eat prepared foods
Temperature: 70 – 83F (21 – 28C)
Neon tetras, at minimum, should be in a 10-gallon (40 l) tank that has been cycled and running for some time, although 20 gallons (80 l) is better for a larger shoal. You should strongly consider opting for a larger tank if you’re new to fish keeping because it allows for a larger margin of error – a department the neon tetra is already lacking in.
Again, they’re not too picky about water conditions once settled and they’re able to adapt to a wide variety of parameters, but it’s best to avoid the extremes. We recommend you keep the water soft (4 – 8 dH,) with a pH between 6 – 6.5 with a temperature between 74 – 77 f and some black water. But keep in mind these are our suggested ideals for a few reasons;
- Higher temperatures “burn out” fish and reduces their lifespan, but go too cold and their immune system and macrofauna in their gut begin to fail. And, not surprisingly, when micofauna fails, their stress levels rise and their immune system is further compromised. Additionally, there are numerous reports of neon tetras not being able to go to above 78 long-term.
- At a pH under 7.0, ammonia can’t be produced and instead comes in the form of ammonium, which is less toxic (although not harmless!) giving additional leeway in the event of minor slip-ups.
- Tetras come from soft to very soft water in the wild and, although far removed for their wild counterparts, putting a soft water fish in harder water is never a great With that said, creating water so soft that it crashes the pH won’t end well, either. We felt that soft was a happy-medium.
- Black water has a variety of health and anti-fungal and anti-bacterial properties that help fight off diseases that neon tetras are particularly prone to.
If this sounds like gibberish to you, check out the aquarium water chemistry series to learn more! With all that said, it’s important to remember that stability is better than ideal, so if you can’t achieve these parameters, we certainly don’t think it’s the end of the world.
A heater, some plants, some low lights (preferably adjustable,) and a sponge filter powered by a small air pump should be sufficient for housing these little Amazonian gems! While they would certainly appreciate tannin-stained water, floating plants, some root systems, and leaf litter, it’s not a requirement for keeping them. If you do opt for black water, we suggest botanicals such as alder cones, Swietenia macrophylla pods, and catappa leaves, but there are plenty of other great options to explore. We don’t suggest peat moss to lower you pH and hardness, it’s not sustainable for the environment and it’s not as effective as so many other methods that are!
Without stained water, some floating plants and a tank with a dark background will certainly go a long way towards helping them settle in and reduce their stress. Tetras in particular don’t appreciate light coming up from the bottom of the tank, so nix the bright and light-colored substrates, and opt for a darker color instead. Not only will this help their colors pop, but it’ll keep them from going pale in an attempt to hide.
Feeding Neon Tetras
Neon tetras are omnivorous, meaning they eat both meat and veg. In the wild they scour the Amazon waters for tasty bits like small invertebrates, crustacea, algaes, and fallen fruits to nibble on. Unmixed Repashy Igapo Explorer, crushed flake, micro pellets, and freeze dried bloodworms will be eagerly gobbled up.
If you’re able to, live foods are great for tetras, especially for newly acquired specimens and breeding stock. Although tetra mouths are tiny, live foods such as daphnia monia, baby brine shrimp, grindal worms, and fruit flies will be happily snarfed down and are easy to culture too!
Neon Tetra Diseases
Unfortunately, years of mass commercial breeding have taken the hardiness out of most neons, so learning how to tell if a fish is healthy before you drop your cash is of the utmost importance.
Neons are susceptible to, realistically, any tropical freshwater fish disease, but these are the most common:
Neon Tetra Disease (NTD)
Also called NTD was first discovered in neons, but affects a wide variety of species. Usually, once symptoms present themselves, it’s too late to treat.
Even if the fish appear to have an untreatable stage of NTD, it’s still worth treating with an anti-bacterial for Flavobacterium columnare.
- Loss of coloration
- Gray patches around scales
- Cysts development may make the fish look lumpy
- Spine may curve
- Difficulty swimming
- Secondary infections are possible
- Flavbacterium columnare (bacteria)
Columnaris (Cotton Mouth Disease)
Occasionally called false neon tetra disease or cottonmouth, this is caused by a gram-negative bacterium. it can also, quite understandable, be confused with fungal infections.
- Discolored scales
- Scales appear to be popping off (not “pineconing”)
- Grey spots
- Lesions on the back
- Legions around the mouth
- May result in fuzzy patches due to secondary infections
- Flavbacterium columnare (bacteria)
Ich (White Spot Disease)
Ich is caused by a parasite that, to many, looks like tiny white pimples across the fish. It can attach to the mouth, fins, body, and gills. You can usually see fish scraping themselves against objects (likely because parasites are itchy!) before white spots even appear.
- White spots
- Redness or bloody streaks
- Ichthyophthirius multifilis (parasite)
Fish Tuberculosis (Fish TB)
Fish TB, or mycobacteriosis, is a zoonotic disease, meaning you and your family could contract it from a fish, and there’s a slight (although rare) possibility you could pass it to your other pets such as your cat or dog.
Although contracting fish TB yourself is highly unlikely, the disease is (as far as we know) uncurable and it’s best to remove the affected fish to a new tank and euthanize it appears to be suffering. If it’s not suffering, you can likely wait it out if you feel like it (although safety precautions are recommended!)
- Wasting of flesh and muscle tissue
- Spinal deformities
- Missing scales
- Severe abdominal bloating and fluid retention
- Several mycobacteria are known to cause this; M. fortuitum, M. flavescens, M. chelonae, M. gordonae, M. terrae, M. triviale, M. diernhoferi, M. celatum, M. kansasii ,M. intracellulare, and M. marinum.
- Research indicates all fish are susceptible to fish TB, but these mycobacteria grow more readily at 77 F (25 C) and up beyond normal water temperatures, they’re more frequently encountered in tropical fish.
Neon Tetra Tank Mates
We’ve all seen the basic community tank suggestions for neon tetras and – to be honest – I disagree with 90% of them. Granted, a well-researched community tank would absolutely work, but most of the common suggestions I would stay away from.
Angelfish? Most would make a quick snack out of the neons once they’re full-grown, given the chance, so why risk it just because some people have had success? Guppies and halfbeaks? I wouldn’t suggest so, both need harder water parameters to stay healthy. Molly? Also no. They’re big, aggressive, and they need harder water and salt to boot. African dwarf frogs? Maybe, but unless you want to spend the extra time playing with foods, it’s probably best to avoid. Ghost shrimp? Maybe, but they can border on predatory for small sleeping fish. Many a horror stories are made with small fish and ghost shrimp at night.
Here are my almost-no-fail tank mate suggestions:
Like with every tank, there are outlier cases that should work that don’t and visa versa. However, here are some near bullet-proof suggestions that have a low chance of failing, providing the right care is given to each species.
Crystal Red Shrimp (Caridina cantonensis)
Crystal red shrimp, not unlike cherry shrimp, come in more colors than just red. They’re a similar size to cherry shrimp and make a great alternative if you’re looking for a little bit more of a challenge. They’re incredibly popular – although more expensive.
pH: 5.8 – 7.4
dKH: 0 – 4
Temp: 62 – 76F (16 – 24C)
Size: 1.25″ (3 cm)
Bolivian Ram (Mikrogeophagus altispinosus)
The underrated cousin to the German Blue Ram are often nearly colorless and shy in the store tanks. But provided with the right tank and dither fish, they’ll color up and exhibit fascinating behavior in your home aquarium!
Keep in mind these rams will also become territorial while spawning. However, there are some sparse reports of other tankmates going unnoticed during spawning.
pH: 6.0 – 7.5
dKH: 1 – 10
Temp: 68 – 83 F (20 – 28 C)
Size: 3″ (8 cm)
Swimming: Bottom to mid-water
Black Neon Tetra (Hyphessobrycon herbertaxelrodi)
Not to be confused with the black tetra (or “black skirt” tetras) or neon tetras (Paracheirodon innesi,) the black neon tetra is a separate species. They do best in groups of eight or more – but more is always better when it comes to shoaling fish. They have the peaceful demeanor of the neon tetra without all the health issues.
pH: 5.5 – 7.5
dKH: 4 – 9
Temp: 73 – 81F (23 – 27C)
Size: 1.5″ (3 cm)
Temperament: Peaceful shoaling fish
Swimming: Mid to top
Toucan Tetras (Tucanoichthys tucano)
These guys are hard to find (but I know a few good spots if you want them!) And they’re completely worth hunting down these rare gems. They’re a peaceful shoaling fish that need to be kept in groups of six or more and the only known wild population exists within a 200-meter range in Brazil.
pH: 4.0 – 6.5
dKH: 1 – 8
Temp: 68 – 83F (20 – 28C)
Size: 1″ (2 cm)
Temperament: Peaceful shoaling fish
Swimming: Mid to top
Sparkling gourami (Trichopsis pumila)
Little known fact about sparkling gouramis; they’re quite social and gregarious creatures! Although they don’t school or shoal, they do enjoy social interactions with their own kind – in fact, most gourami do! – and we suggest a four minimum to make sure they’re comfortable.
pH: 6 – 8
dKH: 5 – 18
Temp: 72 – 81 F (22 – 27 C)
Size: 1.5″ (4 cm)
Temperament: Peaceful, can be aggressive when spawning
Swimming: All water
Corydoras (Corydora sp.)
Corydoras are a shoaling species rarely kept appropriately. Some species can be seen in shoals numbering in the thousands in the wild! While this isn’t easily replicated in the home aquaria, most species are happy in groups of six or more like-minded cats to partrol the sand beds with.
Corydoras hasbrosus would be a particularly adorable addition – although almost any corydora would do well, similarly agreeable in size would be pygmaeus, hastatus, or panda.
pH: 5.5 – 7.0 – species dependent
dKH: 3 – 10
Temp: 72 – 80 F (22 – 26 C) – species dependent
Size: 1 – 3.5″ (2.5 – 9 cm) – species dependent
Temperament: Peaceful, can be boisterous for less active species
Swimming: Bottom (except hastatus) in a shoal of 6 or more
Breeding Neon Tetras
You may have noticed already that there isn’t a wealth of information about breeding neon tetras in a noncommercial setting. In fact, there’s not much information about breeding neon tetras out of Asia. There’s a reason for this: breeding neon tetras is neither easy nor lucrative, so if that’s your goal, check out our list of easy breeding projects. Tetras in general don’t hold much of a breeding prospect for the average aquarium holder and there are much “easier” tetras to breed such as embers, glow lights, and priscillas.
They fry, however, are easy to rehome provided your willing to sell to a pet store for a net loss. On a whole, breeding neon tetras at home simply can’t beat the prices of farmed tetras from Asia. If you’re looking for a challenging breeding project just for fun – then neons are a great option.
Kept in the proper conditions, neons will breed daily from about 12 weeks old, which is often the age we see many of them for sale. If you keep a healthy and well fed shoal in a well planted aquarium with subdued lighting, leaf litter, and no other tank mates, you’ll likely eventually spot the occasional fry or two.
If you want to breed neons at a larger scale – although not commercial – it seems the key to success is slowly reducing the pH and dH over the course of serval days – or weeks, even to prevent shock – with leaf litter, staining the water a deep brown color. Fry and eggs appear to be susceptible to light, so dark water or extremely low lighting is an absolute must for survival.
Often this amount of staining can only be achieved at the risk of a pH crash. In the hands of an inexperienced aquarist, this can be a tough spot, especially if the understanding of water chemistry isn’t well understood yet.
Removing the parents after several days of daily spawning, back into a similarly tannin stained tank of comparable parameters, is also recommended as they will gladly eat their eggs and fry. Making the transition, again, much more difficult to those inexperienced aquarists. Similarly, water changes for the fry must be done with care as to not wildly spike or drop the pH at these levels. Since the tank can’t be cycled – or not fully anyway – at such a low pH, water changes and chemistry know-how are critical for the survival of your fish.
The fry can eat microfauna growing in the leaf litter and will take things like infusoria and rotifers while young. At a few weeks old, they’ll be able to eat freshly hatched baby brine. Reportedly the fry begin to color up at around 4 weeks old and will be ready to sell around 12 weeks old. Although you’ll have to slowly transition the water out of ultra-low range pH and dH before you can consider selling them to any store with a reasonable degree of success.
Certainly breeding neons isn’t for the inexperienced – or faint of heart – but it’s quite possible to do so in your home providing you’re experienced and brave enough to tackle the challenge.
Further Reading & Resources
Practical Fish Keeping – How to Breed Neon Tetras
Seriously Fish – Paracheirodon innesi
Animal World – Neon Tetra
FishBase.org – Paracheirodon innesi
Aquarium Atlas (Baensch Freshwater) Vol. 1