Congo Tetra - Phenacogrammus Interruptus

Large, Colorful, Incredible Finnage, the Congo Tetra Can Light up an Aquarium

Contgo Tetra Comunity Aquarium Fish
Thomas R. Reich PhD

The colorful tetras of South America have relatives just as colorful in the region of the Congo River in Africa. One of these species is the Congo Tetra, which shines in all the colors of the rainbow. It was not discovered until 1949 and was not imported as a common aquarium fish until the 1960’s. For years, aquarists tried to breed this species successfully, and had mixed results, as the beauty of the fish diminished with each successive breeding out of their native Congo River, with the extended central tail area all but disappearing in successive generations.

Then in the 1970’s, Florida fish farms perfected a breeding line, and most examples of this species found in stores today descend from this strain. The Congo Tetras that you buy in most stores today will breed true, with all the color and trailing tail of the native African fish. The fish in nature approaches 4 ½ inches. However farm-raised varieties, though full finned and rich with color, will generally not grow beyond 3 or 3 ½ inches.

These African Characins are found in the upper reaches of the River Congo in Zaire. Their coloration is unusual – depending on the angle of the lighting, nearly all the colors of the rainbow seem to become evident – ranging from yellow through shades of red to green, blue and even violet tones. Males are much more colorful than females; they are considerably larger and have more elaborate fin structure. The females are mostly golden with shades of silver and greenish and have no exotic finnage.

Breeding is really quite easy nowadays if you make a few adjustments from the procedures we have discussed for breeding Characins in other articles on tetras here in, check The Black Skirt Tetra. First, you will need a larger breeding tank than for most tetras, because of the size of the breeders themselves, and because they will produce 300 or more eggs which will most likely all hatch into fry.

This fry will grow rapidly to a size larger than full grown Neons in a month or 5 weeks!

Use a 15 or 20-gallon long tank for this project, though a 10 gallon will work in a pinch, it is not recommended. Boil enough peat moss to cover the bottom of the tank with 1 inch of loosely packed moss substrate (about ½ cubic foot for a 20 gallon long tank) Put it in a tank filled with reverse osmosis, distilled or rain water if in a rural area, and let it sit for 5 days till the peat moss has completely settled evenly on the bottom of the tank.

Place several thickets of Java Moss on top of the peat moss substrate in several strategic locations. Also, provide several nylon breeding mops or several clumps of fine leaved plants. The water temperature should be a steady 77F. There should be no aeration or filtration since this would disturb the peat moss and cloud the water.

Place a well-conditioned pair of Congo Tetra, which has been kept in separate quarters into the breeding tank shortly before turning out the lights, or shortly before sunset. Most pairs will spawn the following morning, or when the lights are turned back on at least 8 hours later. The male instigates courtship by chasing the female up and down the aquarium and flaring his fins at her.

At this time his colors are absolutely stunning.

Once the female is fully aroused they begin diving into the Java Moss or spawning nylon mop and they start to shudder side by side, at this time they release eggs and milt. Some of the eggs remain in the plant or mop, but most fall into the peat moss substrate. As the breeding activities continue, the peat moss will be stirred up, and the water may become quite cloudy, don’t worry, it does not hamper the breeding. When they are finished, you may take your time, but remove the breeders to separate re-conditioning quarters. The eggs will not be eaten since most are well hidden under the peat moss substrate.

Usually, 300-500 or more eggs are laid and hatching occurs from 5 days onward, it may take a week for some of the eggs, be patient. This differs sharply from their South American relatives, whose eggs hatch much quicker, but whose fry hang on the sides or on plants for several days and are smaller and helpless at first.

When the fry appears from the substrate, they are fully free swimming and hungry!

Congo Tetra fry can be fed infusoria for a day or two before they will take baby brine shrimp. They will grow quickly and take powdered dry food within 2 weeks, soon reaching .8 inches long. Within 3 months of frequent feedings of live and commercial growth foods, they will reach 2 inches and show signs of color. At this point, it is even possible to determine sex, but will be 6 months and nearer to 3 inches before they are sexually mature. With growth this quick, the need for a larger tank is obvious!

It is very important not to remove the peat from the fry rearing tank, they need it for water quality, and if you put them in fresh water, they are liable to succumb to fungus. The adult fish also prefer peat moss in the filter or substrate, but it is not necessary and tends to brown the water so it is not really recommended.