West African Killifish: Fundulopanchax Gardneri

Breeding the West African killifish Fundulopanchax gardneri.

The West African Killifish hails from the Cross River drainage of Nigeria and Western Cameroon streams. Via Violaine2, France/Wikipedia

The vast majority of our aquarium fish come from Southeast Asia and South America. Aside from the well-known cichlids of the East African Rift Lakes, relatively few tropical fish come from Africa. Hidden in the rivers and streams of remote West African jungles are some of the most beautiful freshwater fish, with colors rivaling anything one would find in a marine aquarium. If you haven’t guessed yet, I’m talking about West African killifish. One species in particular is the colorful Fundulopanchax gardneri, sometimes called the lyretail killie or the lyretail panchax, though that name is also applied to several other closely related species (Aphyosemion spp. and Fundulopanchax spp.).

Coming to the hobby from the Cross River drainage in the tiny jungle streams of Nigeria and Western Cameroon, these tiny, brightly colored tropical fish are ideal aquarium residents. Reaching an adult size of just over 2 inches, they are small, colorful, hardy, easy to keep and not difficult to breed. It’s a mystery as to why this tropical fish is not more widespread in the retail trade. I can only think this is due to the fact that they are a bit more labor-intensive to spawn than the common tetras and barbs, and not quite as productive; so, that puts a slightly higher price on these aquarium fish (when available). For whatever reason, prices more than a couple of dollars per fish tend to scare hobbyists away, and that’s a shame. Fundulopanchax gardneri are usually sold by the pair, which may put off some buyers, as the females are not very colorful. It’s a good idea to buy the pair, even if you don’t want to breed the fish, as the males display their best and brightest coloration when females are present. However, if you want to breed the fish, it is usually best to purchase at least two pairs.

It’s hard to adequately describe the bright colors of F. gardneri.The males are very colorful, with red dots or splotches on a blue to green background, depending on the location where the fish were collected. Short extensions of the upper and lower rays of the tail create a lyretail effect. These extensions are brightly colored, with yellow, white or blue being common colors, and are usually outlined in bright red. The same color pattern appears in the dorsal fin, and sometimes the anal fin, as well, making it look like an artist outlined the fish in color. You may ask why I’m not giving definitive colors; that’s because there are at least 15 different color variants in the wild, with an additional aquarium-bred albino strain available. Each stream has a different color pattern, and across the range, one might think they are dealing with a dozen or more species instead of just one variable species. But genetically, they are all the same species, and they will freely interbreed. The females of the strains all look pretty much alike, so make sure you don’t mix strains. Females of the albino strain are the only ones that are easy to distinguish. Otherwise keep them clearly marked in separate aquariums throughout their lives.

Many killifish hobbyists keep F. gardneri in small aquariums, sometimes keeping a pair in just a gallon of water. This might seem cruel at first glance, but it replicates the natural habitat pretty neatly. In the wild, they are found in water barely an inch deep, sometimes over a leaf-strewn bottom, other times in a weed-choked area, and even over mud. Adaptation to this extreme environment has lead to another evolutionary “leap” (please excuse the pun)—they are excellent jumpers. Often in this extremely shallow environment, they need to move from one small water hole to another. They do this by jumping, flipping, and otherwise hopping from leaf to leaf and pool to pool.

My late friend, well-known Aquarium Fish International contributor Al Castro, used to tell the humorous story of his first experience with a pair of F. gardneri. He brought them home and put them in a gallon jar. He walked outside to call his wife in from the garden to come and see them. She asked him if he meant the fish that had followed him out. He turned around, and there on the ground was the male, flipping and flopping down the sidewalk. He went inside and found the female flipping her way across the floor. Learn from Al, and keep them tightly covered!

A setup for keeping F. gardneri can be as simple as a gallon jar or as elaborate as a well-decorated planted aquarium. They are ideally suited for the desktop aquariums with built-in filtration and lighting now becoming popular. These nano tanks, from 5 to 10 gallons in size, and with a variety of beautiful plants, would be an ideal home for a couple of pairs.

Water changes are very important. Keep the water as clean as possible, especially in a smaller aquarium, and doubly so if you have no filter in the aquarium. Room temperature is fine, so no heater is necessary, unless the temperature drops into the low 60s Fahrenheit. Then a small heater set to the low 70s will be all that is needed. No filter is necessary, again as long as you change water frequently. Water parameters are not that important, as F. gardneri comes from a wide range of habitats and is pretty adaptable. Ideal conditions would be a pH just below neutral with low hardness. Some killifish hobbyists add salt to the water; others don’t. I’m one of the aquarists who doesn’t, and I’ve never had a problem with them.

As I mentioned, many killifish hobbyists keep them as pairs or trios in small “critter tanks” (the kind with the tight-fitting lids). There is no filtration or lighting, though F. gardneri are not shy, as are many other killifish, and they love bright light. These killifish hobbyists do water changes two or three times a week, and feed live foods exclusively, so there is little pollution in the water. The idea here is breeding. For this, they use a couple of nylon yarn mops. I’ll have more on this method of breeding in just a bit.

I like to use a planted 10-gallon aquarium. I prefer to use what killifish hobbyists call the “permanent method” for keeping and breeding them. This means setting up a standard 10-gallon aquarium with a nice grouping of plants at all levels of the aquarium, including floating plants. I use water sprite (Ceratopteris sp.). The adults live in this aquarium all the time. Fry appear on occasion, and I remove them with a small cup to a separate rearing aquarium. This method is not as productive as using mops, but it is a lot easier.

If you want maximum productivity, there are several things to do to increase egg production. First, separate the adults for a week or two. Feed them heavily on live foods and meaty frozen foods, such as bloodworms and brine shrimp. Give them a lot of water changes. This is known as conditioning the breeders. After about two weeks of conditioning, put the pair together in a breeding aquarium with a couple of nylon spawning mops lying on the bottom. The fish will start spawning within hours. By the next day, the mops should be full of eggs. The eggs can be easily seen in the mops as clear round “bubbles.” Remove the mops to a separate small aquarium or plastic shoebox filled with water of similar parameters as the spawning aquarium. Then add a couple more mops to the aquarium. Give the pair another day or so, and then move them back to the main aquarium. The mops can be added to the same hatching container as the previous mops.

Some breeders add a bit of salt and a drop of methylene blue to the hatch water, along with a slowly bubbling airstone. Others add acriflavine instead of the methylene blue. Still others add nothing special to the hatch water. The idea is to keep any fungus that develops on infertile eggs from infecting the fertile eggs. A variation on this is to use a small dish filled with a hatch mix (water, methylene blue, salt). Hand-pick individual eggs, and drop them one at a time into this hatch container. This is very labor intensive, but it gives the breeder good control, so they can quickly remove any eggs that go bad.

Whatever method you choose, the eggs will hatch in about 14 days. Upon hatching, the fry have used up their yolk sacs and are hungry. They will take newly hatched brine shrimp, vinegar eels, microworms or Walter worms, and other small foods such as commercial fry foods. I gently remove each baby fish from the hatch container immediately after they hatch and move them to a plastic shoebox filled with clean water of the same parameters. I add a clump of Java moss (Taxiphyllum sp.) to the box and a couple of small ramshorn snails to help clean up uneaten food.

The fry grow quickly and in just about 7 or 8 weeks, the young males will begin to color up. If you reach this point, congratulations! You’ve had another successful adventure in fish breeding.

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Fish · Freshwater Fish