Tetra Fish

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Tetra is the name given to many small characiform fishes. Tetras originate from Africa, South America and Central America, belonging to the biological family Characidae. The small adipose fin between the caudal fins and dorsal makes the Characidae stand out from other fishes. Some of the examples are neon tetra (Paracheirodon innesi), which are brightly coloured and easy to store. Hence, they are considered as aquarium tetra fish and quite popular for home aquariums. Tetra fish are characteristically small, hard, lively, and unaggressive. Tetras are egg layers and breed, like other characters, by scattering their eggs among many aquatic plants. The tetras located in pet shops are now placed in several genera, such as Hemigrammus, Mimagoniates and Hyphessobrycon. 

To know what tetra is, you must know tetra is not regarded as a taxonomic, phylogenetic term. It is abbreviated  Tetragonopterus, a genus term formerly applied to many of these fish, which is Greek for "square-finned". 

Many unrelated fish are regarded as tetras as the species from different families as tetras are extremely popular in the fishkeeping hobby. For example, payara (Hydrolycus scomberoides) is occasionally known as the "sabretooth tetra" or "vampire tetra".

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Types of Tetras 

The types of tetras includes the following :

1. Black tetra (Gymnocorymbus ternetzi), known as petticoat fish or blackamoor, is a deep-bodied fish that is almost 4–7.5 cm (1.5–3 inches) long in length. It is marked with black on its dorsal and hind parts when young; the black fades to gray as the fish grows up. Other species of the black widow tetra are the golden skirt tetra, the longfin black skirt tetra, and the colored skirt tetra. There are other similar species that looked like these fishes and often been mistaken for this fish, for example, black tetra (Gymnocorymbus thayeri) and Socolof's tetra (Gymnocorymbus socolofi). These species are not available as frequently in the aquarium trade as others, nor are they as famous as the original black widow tetra.

The distinctive feature of the black widow tetra is black dorsal and anal fins which are easily recognized.  There is one naturally occurring colour variation, which can be white to pinkish-hued. Captive breeding can produce a number of different coloured strains, as well as long-finned varieties. There are other pastel-coloured specimens created with dyes; these fish have been achieved with dyes. The process of dying is often stressful to the fish, which poses a threat to their lifespan. These fish only serve to support this harmful and unethical practice.

These fishes are best kept in groups of six or more, making them an excellent community fish because of their peaceful nature. They can be fed on any food, including fresh, live, fresh, freeze-dried, or flake foods. The best food to give them is brine shrimp, high-quality flake foods, brine shrimp, and any type of worms.

The male species of this fish which are large, claim a territory that they will guard during their spawning periods. The parents have to be removed immediately after the spawning has occurred as they will quickly consume the eggs.

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2. Glowlight Tetra- 

The glowlight tetra (Hemigrammus erythrozonus) is complex and possesses a bright red stripe along the side of its body, and this fish grows up to 4.5 cm long. The glowlight tetra is extremely beautiful and super easy to maintain. It comes from the rivers of Guyana. It is simple and peaceful and can live in different types of aquarium environments.

The female species of glowlights are larger-bodied and plumper than males of this species. The female species have bellies that are more rounded than the males of this species. They need a breeding tank with very soft water of no more than 6 dGH and a pH of 5.5 to 7.0. The temperature has to be kept warm, in the range of 78–82 F (26–28 C).

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3. Neon Tetra- 

The neon tetra (Paracheirodon, or Hyphessobrycon, innesi) is a slender fish. It is very popular with the owners of the aquarium. It grows up to a length of 4 cm, its sides have a neon-like blue-green stripe, and the hind parts are coloured a gleaming red. The cardinal tetra (Cheirodon axelrodi) of Brazil has more red on its body. Neon tetras come from the regions of blackwaters beneath dense forest canopies like  Amazon river basins in Brazil, Peru and Columbia. These regions allow very little light to get through.  Neon tetras live in shoals in the middle water layers and eat small crustaceans and worms. Neon tetras are omnivores in nature, which means they feed both on plants and animals. Fine flake food, live or frozen brine shrimp, small granules or daphnia, and freeze-dried bloodworms are all considered good food choices for them.

Gender differences are not evident in neon tetras. Generally, the female will have a more round belly than the male neon tetras, which can make the blue stripe look curvy on the female, compared to the very straight blue stripe on the male neon tetra body. In addition, they need very specific water conditions, which makes the breeding challenging. If you want to breed them, put up a separate breeding tank where the water hardness should be only pH 5.0 to 6.0 and 1 to 2 dGH.

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4. Silver Tetra - 

The silver tetra (Ctenobrycon spilurus) is almost 9 cm and is deep-bodied fish flattened sideways. The colour of silver tetra is silver. The body of the fish is silvery with a string of blue line that initiates behind the gill and closes at the caudal (tail) fin. They have orange-red fins , and a tint of red can be visible at the top of the eye. Ctenobrycon spilurus, the silver tetra, is a species of tropical freshwater fish. They are also called silver dollar tetra. The fish is native to coastal river basins of Guyana, Suriname and French Guiana and Orinoco River basin, and can be located in shallow, slow-moving streams with heavy vegetation. The temperatures that range from 23–27 °C (73–81 °F) is required for full growth. 

They are commercially bred silver tetra and are considered good for beginners. They are very active during the daytime. This type of fish prefers heavy vegetation in the aquarium with dim light. Alternatively, one can use an aquarium with plastic plants. It is mandatory to keep them in a school of 6–8 other silver tetras in a 30-gallon tank. The temperature of the water should be 24–28 °C (75–82 °F). The fish are peaceful and can be paired with other non-aggressive fish.

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5. Buenos Aires Tetra- 

The Buenos Aires Tetra (Hemigrammus caudovittatus) grows up to 9 cm. Each side has reddish fins and a dark lengthwise, which widens up to a diamond-shaped spot. The Buenos Aires Tetra is very popular because of its hardiness and ease of care. These fish were once sold in big numbers, but they have become less famous over the years because of their propensity for eating aquarium vegetation. The Buenos Aires Tetra is very popular because of its hardiness and ease of care. These fish are used to sell in significant numbers, but they have become less famous over the years because of their propensity for eating aquarium vegetation.

The Buenos Aires tetra takes its name from the capital city of Argentina.   In the wild, they are generally found in rivers, lakes, ponds and streams. They are freshwater fish and do not do well in polluted or highly salty waters. 

The Buenos Aires tetra goes well with larger sized tetras, for example, serpae tetra or the black widow, as well as with barbs, danios, gouramis, and rainbowfish. The fish, which are bottom dwellers, are also good companions for them. 

They breed very easily, and their eggs are scattered fish in pairs or in groups.  A mature female's belly will be rounded nicely when she has full eggs. Maintain slightly acidic water with a pH of 6.5 to 7.2 to neutralize; keep the water temperature at 75 degrees Fahrenheit. Giving sturdy plants such as spawning mops, or java moss is preferred as the fish will scatter their adhesive eggs in that. 

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Essentials For Tetra 


Tetras are a type of schooling fish that originates from the family Characidae. They have characteristics of being calm, colourful and generally peaceful. Hence, it is ideal for both advanced hobbyists and beginners. Popular beginner tetras are red eye, bloodfins, black skirt, Serpas, but neons, glowlights, black neons, and lemon tetras can be considered as good choices. However, like cardinals, penguin tetras and emperors are more difficult to keep and do best in an organized aquarium with more acidic soft water. 

Natural Habitat For Tetras

Tetras are also found in the Africa and Americas, but the majority is coming from the river systems of South America. They mostly dwell in streams and rivers. One of the unique species was discovered in a cave system in Mexico known as blind cave tetra. 

Tetras Water Requirements

Usually, an aquarium tetra fish is commercially raised, which has higher pH and alkalinity, than the naturally occurring tetras, found in soft, acidic water. Ideally, the pH should be kept between 6.8 and 7.8, temperature between 75° and 80° F and the alkalinity between 3° and 8° dkH (50 ppm to 140 ppm) for the tetras. We are using an Aqueon Aquarium Heater to maintain the right temperature if the aquarium is kept at room temperature below 75. However, there is an exception like the Buenos Aires tetra, which does better in cold water. We should change 10% of the water every week or 25% every two weeks using an Aqueon Aquarium Water Changer for better maintenance.  

Housing Requirements For Tetras

All types of tetras can dwell in aquariums of 10 to 20 gallons, but it is advised to use larger tanks as they are easier to take care of and give them more space to swim. They are the best in schools of 6 or more and show their best colours in a well-organized aquarium. Dark substrates and decorations will aid the accent of the bright colours of your tetras. Keep it covered in the aquarium so that they cannot jump out if they feel scared. Provide mild but steady current.

Tetras Behavior/Compatibility

Mostly all the tetra fish types are peaceful and get along well with same-sized community fish. However, there are a few exceptions, like serpae tetras. This type of tetra fish can be sometimes nippy, especially when kept in inadequate numbers. Others, like Buenos Aires tetras, get quite active and large and intimidate small and timid fish. Ideal tank mates for tetras include tetra species, small danios, rasboras, peaceful barbs, appropriately sized rainbowfish and livebearers. It is always advisable to consult an aquarium expert when buying any new fish for your aquarium.

Food For Tetra

Most tetras are omnivorous and will thrive on Aqueon Tropical Flakes, Color Flakes, Shrimp Pellets and  Tropical Granules. Frozen and live foods can be used as treats to induce spawning. Twist their diet daily and feed only what they can consume within 2 minutes, once or twice a day for the best result. 

Tetras Breeding Level - Difficult

All types of tetras do not need movement for breeding but can be bred in captivity, but it is challenging to make the correct environment to propagate. Tetras are egg layers, but the effort is necessary to separate the adults from the eggs after spawning, as many tetras will eat their own eggs. Tetras have the tendency to spawn in groups. Males typically trap females into thick plant growth. Then, the eggs are deposited and fertilized and hatch in a few days. 

Tetras are popular freshwater aquarium fish that come from Africa and South America. They are available in a wide range of colours, including red, white, black, silver blue, yellow, black, orange, fluorescent colours etc. They are considered as schooling fish, so they swim together in clusters and should be dwelled with other tetras. They like to lay their eggs and swim away. 

FAQ (Frequently Asked Questions)

1. What is the Best Food to Give to Tetras?

Ans. Most tetras are omnivorous and will thrive on Aqueon Tropical Flakes, Color Flakes, Shrimp Pellets and  Tropical Granules. Twist their diet daily and feed only what they can consume within 2 minutes, once or twice a day for the best result. 

2. Which of the Species of Tetras is Considered Good For Beginners?

Ans: The small tetra species most commonly found in aquariums is the Neon tetra which can be easily maintained.  These are the types of tetra species found in the aquarist hobby for many reasons: they are great for their looks. Also, they are very peaceful, easy-to-care-for tetra fish that's hardy and great in a community aquarium.

3. Why is it Necessary to Separate the Adults From the Eggs After Spawning?

Ans. It is necessary to separate the adults from the eggs after spawning as many tetras would consume their own eggs. For example, black tetra.