The South American Tetras are considered among one of the largest groups of freshwater fish. They are naturally found in rivers with the waters slightly acidic in nature (around region of 6.5, the lower the better, up to 5.8) and the tetras are often associated with their active behavior, fast swimming ability, small size and most notable is their shoaling characteristic. The fish are collectively known as The Characins or Characidae which also include the African Tetras but to stick to our topic of discussion here, we will only focus on the South American species. There are quite a number of commonly found tetra fish (about 20 to 30) which has been commercially bred and domesticated in home aquariums around the world, and to quote a few examples would be the neon tetra, emperor tetra, banded rummy nose, yellow banded tetra and the black phantom.
Picture left to right: Red Eye, Black Phantom and Rummy Nose Tetra
The water requirements
South American Tetras are well-known for its demands in terms of having the right water quality. Most people failed in their attempts to rear the fish because they fail to understand their most basic requirement whereby only a fully-cycled aged tank (3 months old is the best) is suitable for them to live in and with the nitrate level needs to be as low as possible with the recommended range dipping below the 20ppm cut-off point. And because of that, in order to achieve the required level, you will need to have a highly-dense planted tank in order to establish the perfect aquarium condition.
Also another factor to watch out for is the pH. Based on my own experience although you can keep the tetras living in aquarium having pH close to neutral range, but however, they exhibit higher survival rate and are livelier when kept in water with pH at 6.5. Thus in order to attain that level, you will need to have peat, bogwood added to the tank for the purpose of pH adjustment. Nevertheless the best setup would be an aquarium equipped with an online pH indicator to give an on-the-spot reading on the actual water pH.
The South American species are also considered tropical fish and thus, the right temperature should be at least 27deg Celsius minimum. This is to ensure that they propagate and most important is to minimize the chance of developing unwanted disease. Thus, if you are living in cold climate countries, be prepared to invest on getting a reliable aquarium heater to ensure the water temperature maintains at a stable range.
Life spans in captive aquariums
Tetra fish are known to live for at least 2 years minimum with some species like the emperor tetra surviving as long as 5 years. This is provided that their welfare is well-taken care off and with the best nutrition, it is not uncommon to see the fish reaching an average life-span of 3 years. Most novice hobbyist laments on how difficult it was to care for the fish, with some experiencing their pets dying in just a matter of days or even hours after they were released into the aquarium but my advice is, as long as you follow the basic water requirement detailed out above, your fish should be fine.
Let’s us study some of the most popular aquarium tetra fish:
Black Phantom Tetra (Hyphessobrycon megalopterus)
Black phantom tetra is easily identified based on the presence of a black color patch appearing close to the area adjacent to both sides of the gills. They have a relatively transparent-like body with certain variant of the fish appears to be slightly brownish in color. They only attain size of up to maximum 2 inches in length and just like their other tetra cousins; they share a similar non-aggressive, active and shoaling trademark. Trying to identify between a male and female should prove to be relatively easy as the males have a longer dorsal fins compared to the female fish. Feed them mixture of live foods and dried flakes which they would readily accept.
Banded Rummy Nose (Hemigrammus rhodostomus)
Banded rummy nose is an Amazonian species with its signature red color tip appearing at the front end of its body which is very noticeable. Unlike the other tetra fish, this one has an overall longer torpedo-shaped body. Similar like the black phantom tetra, they only reach a miniature size of 2 inches in length. The color pigment of its body is slightly yellowish on the upper half while the rest of the lower half is silvery. The fish is peaceful and highly sociable in nature, and is definitely a recommended choice, suitable to be added to a community aquarium. Their choice of tank mates should be limited to other non-aggressive species like for example platy, bristlenose catfish, rainbowfish or guppy and you can even consider picking the other South American tetras to keep them company.
Yellow Banded/Red Eye Tetra (Moenkhausia sanctaefilomenae)
The yellow banded tetra is different from the other fish marked by the presence of a thin reddish line appearing on the top of its eye. Overall, when viewed at certain angle, you can actually distinguish the yellowish shade appearing on its silvery scales and the patch also appears more vividly at its tail region combined with black (refer to the picture above). Unlike the other tetra which is relatively small, the yellow banded tetra can reach slightly bigger size up to 3 inches in total. Overall, the shape of the fish is rounder but however, this characteristic does not deter them from being a fast swimmer. Just like all the other tetra fish, they prefer moving in groups, with the presence of their own kind around them and they seem to exhibit stronger shoaling behavior as you rarely find one fish straying away from the group
Neon Tetra (Paracheirodon innesi)
This is perhaps the most popular of all. The neon like appearance is very profound especially when viewed under the fluorescent light. However, compared to the other fish, neon tetra can be very susceptible to disease and sometimes you can end up losing a whole batch of fish without any clear indication to show that they are infected. Neon tetra is characterized by the combination of 3 standard colors, the most is blue, then red and some part at the belly region is silver. They can only breed when pH drops below 6.0 and healthy specimens often display brighter neon coloration (a clear indication of their health status). Females have thicker and plump body, a sign that they are carrying eggs while males are slightly thinner and shorter in length. More information on neon fish can be found at this page about general information and another written post about breeding neon fish.
2) Avoid keeping the tropical South American Tetra with brackish water fish like Mollies
Aquarium Fun Facts:
1) Do you realize that the Characidae fish group once included the Sabre Tooth Tetra or better known as Vampire fish, which has been reassigned to its own fish classification?2) Avoid keeping the tropical South American Tetra with brackish water fish like Mollies
