Silvertip tetra (Hasemania nana) are freshwater tetra fish native to blackwater rivers in Brazil. Silver Tip Tetras are slightly more aggressive than other comparative smaller Tetras, observed to occasionally nip other similarly sized Tetras.
The males have a copper color, the females are more pale and silverish. Both have white tips on the fins, hence the name. They differ from most other tetras by lacking a small second dorsal (adipose) fin. Silvertip Tetras have a Black area at the base of their cadual fin. The fish are transparent except for that fact that their bodies have an overall Copper sheen. During the night, the copper and black become silver as the fish rests — it reactivates once it becomes active in the morning. It grows to approximately 3 cm (1.25 in) in overall length. Sexual dimorphism is slight, the female having a very slightly larger belly, and slightly paler and silver compared to the male's golden copper color.
Silvertip Tetras are found in Blackwater rivers in Brazil.
In the Aquarium
Silver Tip Tetras prefer a densely planted aquarium, with a dark substrate. They prefer a space in the center for swimming room, as it is recommended that a group of 10 Silver Tips be kept in a 15 gallon tank. The fish come from very soft and acidic waters, so when these conditions are met, Silver Tips' colors become brighter and more vivid. They are a shoaling fish and should be in a group of a minimum of 6 Silver Tip Tetras or other fish very similar in size and temperament. They do not tend to swim at the surface of the water nor at the bottom as other smaller tetras usually choose either level, rather they tend to occupy the middle of the aquarium. While tank bred Silvertips have adapted well to a wide range of water conditions, in the wild they inhabit very soft, acidic waters. Silvertips have a lifespan of about 3 years.
Silvertip Tetras are considered moderately easy to keep in a community aquarium with a pH of 6.0 - 7.5. However, they will not tolerate dramatic changes to their environment. They tend to be moderately aggressive and, because of their small size, should not be kept with large or aggressive fish who may bully or simply eat them. Fish that mix well in an aquarium are other types of slightly larger tetras, such as the rummy-nose tetra, Buenos Aires tetra, and Black Neon tetra, and other community fish that live well in an ideal Tetra water condition. Mid-level feeders, they are best kept in schools of five to six or more, for the shoaling effect when they move around the tank. They shoal naturally in the wild and are thus happier, more brightly colored, and more active when kept as a shoal as opposed to singly. The color may also fade during a period of stress. Silvertips are best kept in a densely planted tank with subdued light and an ideal temperature of 72-78 degrees Fahrenheit to resemble their native Amazon environment. Given the origins of the Silvertip Tetra, namely blackwater rivers whose chemistry is characterised by an acidic pH, low mineral content and the presence of humic acids, the species is adaptable to a wide range of conditions in captivity, though deviation from the soft, acidic water chemistry of their native range will impact severely upon breeding and fecundity. If the intention of the aquarist is to breed the species in captivity, then the water chemistry of the aquarium water should match that of the wild habitat - filtration of the aquarium water over peat is one means of achieving this. Fine-leaved plants such as Cabomba are usually the plants of choice. Floating plants providing shade will also be welcomed by the species: this is connected with the breeding of the fish.
To breed Silvertip Tetras, place a pair of the species in a breeding tank without any light, and gradually increase the lighting until spawning occurs. A perfect biotope to promote breeding, would be lots of bogwood, a few live native plants, with dark substrate and subdued lighting with floating plants. Other inducers include mosquito larvae and a hardness of less than 4 degrees. Some also recommend to at least 50% water change. It is recommended that everything you place in the aquarium be sterilized, as well as the aquarium top. Because the adults will often eat newly-hatched fry, it is best to remove them as soon as the eggs have been laid. The eggs are especially sensitive to light. Eggs will hatch within 24 hours after laying. Fry can be fed rotifers, especially infusoria and egg yolk for 1 to 4 weeks, followed by nauplii of brine shrimp Fry will achieve their adult coloration at approximately one month of age. Adults can spawn every two weeks.
Silvertip Tetras are susceptible to common freshwater diseases such as Ich.