Paracheirodon axelrodi / Cardinal Tetra
by Skip Waskowiak

This fish is a small tetra from South America, it's the Cardinal tetra. Paracheirodon axelrodi is a small tetra widely distributed from Orinoco in Venezuela through RIO Vaupes and north and east tributaries of the RIO Negro in Brazil to western Colombia. The Cardinal Tetra is a schooling fish, very peaceful and recommended for most community tanks. They are hardy and not extremely susceptible to disease. It should be kept in schools of six or more when keeping them in a community tank. The Cardinal Tetra was once though to be very hard to breed, but with today's R.O. units and chemical available to the hobbist, this fish is not a fish beyond the advanced hobbist. The Cardinal Tetra grows to about 2 inches and very comparable to the well known Neon Tetra.

The color of the Cardinal Tetra is spectacular. Their back is olive brown, the upper part of the body has a brilliantly glowing iridescent blue green stripe. The lower part of the body is a blazing red with the belly being pure white. This fish is usually found in slow or standing water. the water in which the Cardinal Tetra comes from are brown, like the color of tea, and very rich in humic acid, and also very low in mineral content. This fish does very well in just about any type of water you keep them in. There is no reason to adjust the water chemistry unless you want to breed this fish.

Breeding this fish is not difficult if you follow these simple instructions. The first thing you need to do is go to your favorite pet store and purchase about 10 adult Cardinal Tetras. Next place them in a ten gallon tank filled with aged water, and feed them well for about two weeks. I feed my fish live mosquito larvae, micro worms, black worms, white worms, live baby brine shrimp and some flake food crumbled up to very small pieces. I change water, about 40 %, every day. At the end of two weeks you should be able to notice the difference between males and females. The slimmer fish will be males and the plump fish will be females. At this time I separate the sexes into separate five gallon tanks for about another two weeks. During this time I prepare the breeding tank. The breeding tank is very special. The tank is a five gallon tank. Start by spray painting all the sides, bottom and glass top with black paint. Give the tank about two or three coats of paint so that no light can get into the tank. Don't get any paint inside the tank or you may kill the fish when you put them into the tank. Let the tank dry for two or three days. Clean out the tank very thoroughly and fill the tank with R.O. water. Remember you can not use the Reverse Osmosis water with your fish without altering this water. R.O. is very pure water, just plain H2O. Fish don't do very good in straight R.O. water. I use R/O Right from Kent Marine, pH Control Minus from Kent Marine and Blackwater Extract from Tetra in my R.O. water mixture. Adjust the water in the breeding tank to a pH from 5 to 6 and a DH from 1 to 2. Add the appropriate amount of Blackwater extract and presto you have it, Amazon river water !

Next thing you need to do is go to the attic and dig up that old fishing pole. No, your not going to fish for those Cardinal tetras, boy what size hook do I need to catch a Cardinal Tetra? What you need is the old monofilament fishing line off the fishing reel. Wrap up the line into a ball about the shape and size of a football. This is what we are going to use for the spawning media. After you have the tank prepaired and the R.O. water in and the two week have passed, then now is the time to place the Cardinal Tetras in the tank. Two or three days before you put your male and female Cardinal Tetra in the breeding tank adjust the conditioning tanks, the one with the males and the other one with females, to the same pH as the breeding tank. Select the best looking male Cardinial and place him in the breeding tank. The next day select the plumpest female Cardinal in the tank and place her with the male in the breeding tank and place the top on the tank. The breeding tank should be from 75 to 78 degrees and no air supplied to tank. The tank should be placed in a dark area. Now the fun comes into play. YOU CAN'T PEEK ! into the breeding tank for two days. Light seems to kill the eggs and fry so don't let any light into the breeding tank. After two days, use a flash light, to catch the breeders out of the tank. If all goes well in 5 or 6 days you have baby Cardinal Tetras swimming around in the breeding tank. The eggs start to hatch two to three days and are free swimming in 5 to 6 days. The eggs should be kept in darkness until they hatch and are free swimming. Gradually increase the light to the breeding tank. At this time the baby Cardinal tetras should be feed. The best type of food is Infusoria and or Green water. Whatever you do DON'T OVER FEED !!!

Over feeding kills more fish than anything I know of. The eggs should number from 200 to 500 eggs per spawn. Once the fry have grown for a week you can try them on newly hatched brine shrimp. From this point the fry grow very rapidly and take seven to nine months to mature.


WATER: Soft - 1 to 50 ppm - 1 to 2 DH

pH: 5.4 to 6.0

TEMPERATURE: 72 to 80 F.

BREEDING TEMP: 75 to 78 F.

TANK SIZE: 5 to 10 gallon

FOOD: All types of live food, some very small flake food

WATER CHANGE: Adults - 40% every week

Fry - 10% every Two days

FILTER: Sponge type

DECOR: Adults - Bare tank - monofilament fishing line

FEEDING: Two to three times a day

LIGHTING: None - These fish don't need light when breeding and the eggs are light sensitive


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