Profile of the Buenos Aires Tetra Fish

Buenos Aires Tetra

Because of its durability and simplicity of maintenance, the Buenos Aires tetra is quite popular. These fish were previously quite popular, but their proclivity for devouring aquarium has caused them to become less so over time. The majority of the specimens are captive-bred from Florida commercial fish farms.

Species Overview

Common Names: Buenos Aires tetra, diamond spot characin, red cross fish

Scientific Name: Hyphessobrycon anisitsi

Adult Size: 2.75 inches (7 centimeters)

Life Expectancy: 5 years


Family Characidae
Origin Argentina, southeastern Brazil, Paraguay
Social Peaceful, shoaling fish
30 gallon
Diet Omnivore
Breeding Egg scatterer
Care Easy
pH 5.8 to 8.5
Hardness Up to 35 dGH
64 to 82 F (18 to 28 C)

Origin and Distribution

The Buenos Aires tetra takes its name from Argentina's capital city. The city is located on the western bank of the Ro de la Plata, which runs down South America's southern coast. The Ro de la Plata, which is considered a river by some and a gulf by others, is formed by the confluence of the Paraná and Uruguay Rivers, both of which are home to the Buenos Aires tetra. They may also be found in rivers, ponds, lakes, and streams in the wild. They are freshwater fish that do not thrive in saline or contaminated environments.

Colors and Markings

The Buenos Aires tetra is one of the bigger tetras, reaching almost three inches in length. It has a silvery body with a short blue line running from behind the gill to the caudal (tail) fin, where a black diamond-shaped spot may be found. The fins are orange-red, and the top of the eye has a splash of red. There are several color variants, including one with a golden tail, as well as an albino type.


Tetras from Buenos Aires are gregarious fish that swim in groups. Although Buenos Aires tetras are typically calm, they should not be kept alongside smaller fish like neon tetras. Also, keep them away from long-finned fish like bettas and angelfish. Long-finned tankmates will be nipped by Buenos Aires tetras.

The Buenos Aires tetra gets along with barbs, danios, gouramis, and rainbowfish, as well as bigger tetras like the or serpae tetra. Fish that live on the bottom are excellent companions. A school of Buenos Aires tetras can also be used as a dither fish for non-aggressive cichlids, allowing them to come out of hiding.

Buenos Aires Tetra Habitat and Care

The Buenos Aires tetra is a low-maintenance fish that may thrive in a variety of aquarium settings. Water temperatures that are acceptable range from the mid-60s to 80 degrees Fahrenheit, making it suited for both heated and unheated tanks. It is a very energetic fish that requires a lot of open swimming room. Tanks that are longer are good.

However, because the Buenos Aires tetra is known to eat flora, it is not ideal for most live planted aquariums. Instead, use fake plants or choose tough like anubias, Java fern, or vallisneria. Driftwood and pebbles around the tank's perimeter will complete the look, and your Buenos Aires tetras will feel right at home.

They thrive on any sort of substrate and are quite content with standard aquarium lighting. However, because these fish are superb jumpers, the tank should be securely covered if given the opportunity.

The Buenos Aires tetra is particularly vulnerable to nitrates and phosphates that accumulate over time, as well as increased water hardness owing to evaporation. Water should be replenished on a frequent basis to fight these ever-changing circumstances. Every other week, at least 25% to 50% of the tank water should be replenished, especially if the tank is heavily populated.

Buenos Aires Tetra Diet and Feeding

Buenos Aires tetras are omnivores that will accept a wide variety of foods. Feed these tetras several times a day but feed only what they can consume in three minutes or less at each feeding.

They consume worms, crustaceans, insects, and plants in the wild, but in the aquarium, they will eat a wide variety of live, fresh, and flake meals. Provide this fish some lettuce, spinach, or other greenery to consume, given its proclivity for consuming live plants. You may substitute top grade spirulina flake food for fresh greenery.

Flake, dry, and freeze-dried foods will provide much-needed variety in their diet and will be well-received. Offer live feeds like bloodworms, daphnia, brine shrimp, and mosquito larvae to keep these tetras looking their finest and most colorful.

Gender Differences

Males of the species have brighter, redder fins and are generally more colorful overall, particularly during spawning. Females are larger and broader with a rounder belly. 

Breeding the Buenos Aires Tetra

The Buenos Aires tetra is a simple to breed egg dispersing fish that may be spawned in pairs or groups. Use roughly the same number of men as females if spawning in a group. When a mature female is full with eggs, her tummy will become pleasantly rounded. The most colorful men should be chosen.

All spawning fish should be fed live meals before attempting to spawn. Maintain a pH of 6.5 to 7.2 in the water and a temperature of 75 degrees Fahrenheit. A sponge filter, for example, is recommended for gentle filtering. Provide strong plants like or spawning mops for the fish to distribute their sticky eggs on.

This species normally starts spawning around daybreak. Females can produce up to 2,000 eggs, which they drop on plants or green floss. Once the eggs have been deposited, remove the adults. These fish do not show parental care after spawning and will eat the eggs and young, therefore keep this tank separate.

The eggs should hatch in around 24 hours. The fry will have devoured their and will be free to swim in three to four days. Feed the fry or commercially prepared like Liquifry at first. Feed them freshly born brine shrimp, micro worms, or finely ground high-quality flake food or fry meal as they get larger.

More Pet Fish Species and Further Research

If Buenos Aires tetras appeal to you, and you are interested in some compatible fish for your aquarium, consider these species:

Check out additional fish species profiles for more information on other  fish.