The Diamond Tetra, Moenkhausia pittieri, is a peaceful little fish from Venezuela. Other common names are the Monk Tetra and the Moenk tetra. It comes from Lake Valencia and the surrounding rivers. It is not threatened in the wild.
The Diamond Tetra grows to about two and a half inches (7cm), and will live for up to 5 years.
Water Conditions
In the wild, the Diamond Tetra lives in slow moving streams and lakes with a lot of vegetation. A well planted tank will make them more comfortable. Although the Diamond Tetra can take a surprisingly wide range of pH with very slow acclimatization, 6-7 is its ideal range, so it has no trouble with a community tank with neutral pH (7). 24 degrees C (75 degrees F) is a suitable temperature to set the thermostat.
The water where this tetra comes from is soft. The Diamond Tetra can be acclimatized to hard water, but this has to be done very slowly. I have never had any trouble with this fish in our moderately hard water.
Food
The ideal food for the diamond Tetra is aquatic larvae and small crustaceans like Daphnia, but it will take all normal fish foods.
Companions
The Diamond Tetra is a strongly schooling fish, and I suggest that at least 6 be kept together. In a school, it is a peaceful fish, and I have never known it to be a fin nipper, which does not prove it would never nip a fin. Certainly this type of behavior would be more likely if there are only one or two Diamond Tetras in the tank.
A school of Diamond Tetras should be all right with a very wide range of small fish.
In all cases, you need to observe your fish. They do not always act as we expect.
Avoid large, aggressive or predatory fish with Diamond Tetras.
Sexing
A female Diamond Tetra in breeding condition will be fatter than a male. The males seem to have slightly longer fins than the females.
Aquarium Breeding
A pair, of Diamond Tetras will spawn in an aquarium with an area well planted including fine leaved plants creating a well shaded area. The pair should be well conditioned before hand with rich food including live food.
The water should be very soft and slightly acidic. A temperature of 26 degrees C (79 degrees F) is suitable.
The fish usually spawn in the early morning. They will eat their eggs and are normally removed after spawning. The eggs should hatch in about 36 hours and the fry are usually free swimming in about 4 days.
The babies grow quickly. They will eat fry foods, but suitable sized live foods will help at all stages.
Pond Breeding
The diamond Tetra is a tropical fish and could not be expected to survive the winter in temperate regions, but some breeders have had considerable success simply by putting a small school of Diamond Tetras in a large well planted pond in the spring when the water has warmed up, and catching all the large number of fish produced six months later, before the water gets cold.
If this is contemplated, commonsense needs to be applied. Firstly think about whether your climate is actually warm enough in the summer. Then you will need to be quite certain that the fish cannot get out into the wild.
Also, you should enquire about whether this is legal where you are; in some areas, the law allows a type of fish to be kept in an aquarium but not a pond.
PestFish
Do not release or allow any fish to escape into an ecosystem it is not native to.
