Beginners Guide to Killies 1

Beginners Guide to Killies

As a short preface and disclaimer, I wish to stress that there are hundreds, if not thousands of species of killies, and there is no one set of rules that can be applied to all of them. The following applies in general to a very large number of African killies; namely Aphyosemions, Fundulopanchax and Epiplatys. Part of the joy of keeping killies is for you to find out what works for you for a particular species. The following is intended to provide a good jump start on this knowledge. Additionally, killies are most often kept as a “breeder-hobbyist” fish, not for a decorative community tank in the living room with a “red one, green one and some of those blue ones” to be replaced easily when they are lost. Killies are great and avid jumpers. KEEP TANKS WELL COVERED. They can be escape artists. Non-annual killifish typically have a lifespan that depends upon water temperature. Warm (78 ish) degrees usually results in a half year of growth to maturity and an adult lifespan in the realm of an additional 2 to 3 years. Cooler water killies (i.e. 70 ish temperatures) adds another half year to maturity and another year to lifespan. Remember, these are generalities.

As a starting point, killies are egg laying toothed carps, the “cousins” if you will, to live bearing toothed carps (guppies, platys, swordtails etc.). They are small top minnows. They live in nearly all regions of the world.

Why the stupid Latin names?

The real question should be “Why are all fish not given their proper names?” With the true species names, the fish are recognized by hobbyists world wide. With local “colorful names” based on some attribute or sometimes nothing at all, a uniform identification is near impossible. For many killies it is taken a step further and within a species the location of collection, year of collection and a collection code sometimes made from initials of the collectors is used. Why be so specific? A “local variety” of a species may actually be a new and different species. Also, just as dogs are sold as “purebreds” so are killies where possible. You do not just ask to buy a dog; you identify which variety you are after. From a good breeder, you get assurance that the dog you bought will “breed true” to its variety.

Annual versus Non annual killies

A significant division is made between those that live in permanent bodies of water and those that live in temporary bodies of water and thus live a short life span, only during the period that water is present. Killies in this group are known as “annual killifish”. The annual killifish place eggs in the substrate of the habitat, sometimes actually diving into the dirt or sediment at the bottom and disappearing from sight until an egg or a few eggs are deposited. The eggs will lie in the mud or silt essentially undeveloped until the pond or stream dries out. Once dry, the eggs begin to develop and when the rains again come, some of the eggs will be ready to hatch. Not all will hatch the first time the water returns since in nature it may again quickly dry. Some eggs wait for the second or third wet period to hatch. The fry grow quickly and are usually very competitive since there is little time to again start a new generation. Such annuals include many South American killies and African Nothobranchius species.

Until a “killie hobbyist” gets his or her “feet wet”, in my opinion it is best to start with the “non” annual killies. This is for two reasons. First, annuals are best obtained either directly from a breeder or via eggs. If there is no one locally raising annuals, eggs are the best choice. With eggs, you must be prepared for a long wait (3 to 9 months, depending on species) for the proper wetting date. This wait can be discouraging. Second, incubation temperature does play an important role in the length of the incubation period. A beginner may not have the controls necessary to assure that the proper temperature is maintained and thus try to hatch the eggs either too soon or too late. Once hatched, the fry must have food immediately and a “beginning” killie hobbyist is usually not well prepared for this.

I am trying to only “temporarily” discourage beginners from working with annuals. I feel it is better to start with some non annual killies, breed and raise fry and then try annuals. In addition, I have not kept or raised many annual killies and could not provide much sound advice. If you are determined to try annuals, I suggest Cynolebias (now Simsonicthys) whitei as an excellent annual killifish for a beginner.

Simpsonichthys santanae man
Simpsonichthys santanae man

Non annual killies include some of the most colorful of freshwater fish, equaling many of the salt water fish in beauty. If conditions are right, they will lay a few to many eggs every day. Eggs typically take 2 to 3 weeks to develop and hatch. Killie fry are not like fry of many other fish in that they are hatched free swimming and looking for food immediately. They are in relatively hard egg shell membranes and consume all egg nutrients prior to breaking out of the egg shell. Since eggs are laid only a few at a time, there is no “spawn” of fry to raise, but many fish of different ages. This is probably one of the biggest reasons killies are not commonly raised or sold commercially. Another reason that killies are a “breeding hobbyist fish” rather than an “addition to the living room tank” is that they are not all that easy to find. You cannot just run down to the local fish shop and get a “female” because yours died or jumped out. You start with 2 pair of a species, breed them and keep that species generation after generation. If you do not, there is a chance you may not find that species for a long time. Very few breeders will sell a single sex unless he or she has an excess of that sex. Also postage alone for a replacement can actually exceed the initial cost of a second pair!

Although many killies can do well in a community tank, most people who keep killies keep them in tanks isolated by species. A “breeding tank”, usually a 2½   to 5½  gallons is used for each adult pair. Small containers known as “egg boxes” are used to raise fry for a few weeks to a month, and larger tanks are used to raise fry after a month or two of age. (At this age, they are too big for their older brothers and sisters to eat and fish of several weeks to a month of age difference can be put together). When raised together, a natural hierarchy of dominance is established and competition among males is avoided if there is enough room for the fish. Different species of killifish are usually not mixed in the same tank, unless males only are used. If the species are very different, like a species of Epiplatys with a species of Aphyosemion, it is safe to mix them assuming similar size and temperament. Females of many species look very similar and are difficult to distinguish for you and for males. Males will mate with females of different species and produce sterile offspring that in some cases will survive but may look like one of the parent species. This is NOT GOOD! If such “mules” get out into the hobby, they can doom a species in the hobby. Remember mixing DIFFERENT species, is not like mixing a cocker spaniel with a collie (both dogs – same species, just different varieties). You don’t get a “mutt” you get a sterile offspring. As with purebred dogs, different varieties and different locations of the same species are not mixed since for many hobbyists, purebreds are more desirable.

Aphyosemion ogoense
Aphyosemion ogoense

OK, I want to try killies-what now?

First you need to know a few things. Answers to the following will determine which, if any, killies will work out well for you. Most Aphyosemion, Epiplatys and Fundulopanchax species are best bred in soft, acidic water.

1) What is your water like? Hardness (DH), temperature, and pH
2) Are you willing to use live foods? Hatch brine shrimp, raise white worms or daphnia, or restrict yourself to flake or to frozen foods? Buying live foods at the local fish store can get quite expensive.

1) Most Aphyosemion, Fundulopanchax and Epiplatys killies will survive in hard alkaline water, however, their natural habitat is over igneous rock and the water can therefore dissolve few minerals, assuring soft water. Calcium and magnesium carbonate in the water can cause the egg membrane to “harden” before it is fertilized, resulting in mostly sterile eggs. The fish do not mind (usually), but the eggs will. If your water is DH 0 to 4 from the tap, you are in very good killie country. If 6 to 10 DH, many species will still do well (many of the Fundulopanchax typically). If much greater than 10 DH, you will probably have to take some measures to provide water more suited for them. AS a very limited supply, store purchased distilled(not spring) water can be added in small quantities to a breeding tank. A reverse osmosis unit to produce such pure water at home (cost – typically $80 to $200) is the salvation to many killie keepers for an excellent supply of desirable water. If you have very hard water >15 DH, consider lake cichlids, a very restricted menu of killies, or the need for a source of better water.

Killies from Africa live in a range of temperature zones. Some do best in the 65° to 68° Fahrenheit range, some in the 70°-73°  range and some in the upper 70° range. Although many can survive in water from 50° to 80°, breeding is usually restricted to the preferred temperature for that species. Fortunately, pH is not that difficult to adjust. Some garden variety, sphagnum peat moss (not Michigan peat potting soil!) placed in the tank in a box filter will lower pH to the desired range quite easily. A pH in the range of 6 to 7 is usually more than adequate. Many non-annual killies will do well above 7.0, however most that I have raised do best in the 6 to 7 range.

2) Although many killies will take frozen or flake foods, live foods are better for all and especially if you want to breed them and raise fry. Some home prepared formulae are excellent, however live food is often necessary for feeding fry since motion attracts them to the food. This is probably true for most all aquarium fish if your intent is to breed them successfully. Epiplatys species usually prefer to feed at the surface and many will be quite happy with floating foods like flake food and frozen clumps of food which float. Fundulopanchax are typically prone to feed in the middle to bottom of the tank. They are usually larger than Aphyosemions and less shy, so frozen foods usually will be taken. Many Aphyosemion species are shy and unless very hungry will be hesitant to venture out from cover to seek food that is not moving. As with all of the above, there are exceptions.

3) Finding a source for killies is a never ending game. As you decide to venture into more and more species, you will be contacting more and more killie keepers. A great investment is a membership in the American Killifish Association (AKA). If in Canada, The Canadian Killifish Association CKA. An annual membership is worth the cost if only as a source for a list of AKA members near to you. Additionally affiliate clubs, fish and egg listings, articles on keeping and breeding species and a wealth of information can be on hand for the membership dues. If you “get into” killies, a drive of 100 to 200 miles is considered nothing to see another’s fish room and acquire a different species.

Why so expensive?

Even easy to breed and raise killies are still a lot of work. To breed the fish, raise their young and package for shipment, $6 is a real bargain. It likely represents absolutely no profit to the seller. Most killie breeders do it as a pleasurable hobby and try to sell their extra fish, to make room for more and to help cover the costs for food for their fish. Good starter fish are usually between $6 and $10 a pair. More difficult species are sometimes found at super bargain prices ($12 to $20 a pr.), but usually in very limited numbers. Such fish are difficult to find. The breeder had to search and probably spend a pile on his initial pair(s) and does deserve some credit for even making them available, usually at a fraction of his initial purchase cost. Depending on availability and difficulty, killie prices can range from about $6 a pair to well over $100 a pair during club auctions of new and/or rare species. Fish of this type should be avoided by the beginner until he or she has some experience that shows success. In any case most people who have such fish will not sell them to a beginner since it is not “profit” that drives the sale, it is a desire to spread the fish in the hobby to those he feels will do well with them after all the efforts he has taken to acquire and raise them.

What kind should I start with?

This can usually be determined once you have answered the questions on water and food supply. For good beginner fish, usually most Fundulopanchax gardneri varieties are good. They can do well in a wide variety of water conditions and take to frozen foods well. For cooler water, Aphyosemion striatum varieties are a good choice. Talk via phone or e-mail to your potential source. Be prepared to answer the above two questions and to give some measure of your prior aquarium fish experiences. This will allow the breeder to help you select a species or two for starters. ALWAYS try to get two pairs of any given species. This is very important. If a single fish is lost, you will still have a pair and a spare with a 50/50 chance of having a pair after a second loss. In addition, just like people, some individuals are more prolific than others. If you get a single pair and do not have any luck in breeding them, it could be the fish and not you! Do not be surprised if the breeder will sell only pairs. If he or she offers trios, it is usually only because he has an excess of one sex. Do not expect a breeder to sell you a single sex of a species. In doing so, unless he has an excess of that sex, he is stuck with the mate. Learn what the breeders water chemistry is like and what foods he has been feeding. This is important to prevent early loss of your new fish. If your water does not match his within reason, arrange to receive a bag of his water with the fish. The postage is more, but well worth the cost in ease of acclimation.

Be pleased, if the fish are young (possibly only half adult size). Young fish acclimate much better and you are much more likely to have success with them. Good breeders will not typically sell older killifish. A large pair may be young but well nourished. Any non annual 4 months to a year of age is reasonable. Some colder water killies do take a year to mature, but these will probably not be good beginners killies anyway.

In my experience it is usually beneficial to have a single pair of fish in a breeding tank. A third fish will, in many cases, eat eggs or young of the breeding pair. I have found a reverse trio (two males) less prone to such behavior than a trio (two females). An odd male will compete with the other male for the female, but a female will follow a pair and eat eggs as they are laid.

Aphyosemion ecucuense
Aphyosemion ecucuense

OK, I got them, now what?

First, if possible, notify the seller that they arrived alive and well. He has more of an investment in these fish than the selling price. He has probably nurtured them for at least 5 months already and is anxious to know if the fish arrived alive and well. If the seller guaranteed live delivery, I would not expect him to honor this guarantee if you wait a week to notify him of a loss.

Remember, these fish are not from your local fish shop and therefore are not acclimated to your local water supply. Above, I told you to find out what water and foods the fish you got are accustomed to so you can provide as easy an acclimation as possible to avoid losing or stressing your new fish. Hopefully you have some water prepared that is similar to accept the fish. Mix no more than 25 % of your prepared water with the water in which the fish arrived. Maintain this condition, in the bag, for a few hours. A small “critter carrier (1 quart size)” works well for this also, but avoid strong lighting so as not to frighten the fish. Dashing against a hard tank wall can be a lot more damaging than hitting the soft wall of a bag. After a few hours, you can start to drip your water into the container holding the new fish. One drop per second should be fine. A standard airline is good for this. Just tie a loose knot in the airline and tighten the knot to slow the water to droplets rather than a flow. It takes several days to a week for a fish to acclimate to changes in DH greater than a factor of 2. A change to softer water is more stressful than one from softer to harder water than which the fish were accustomed. Keep this in mind before changing your new fish over to your home water supply.

If you have not set up water for your new fish that is similar to that which the breeder suggested, you are in for some patience, work and risk. It takes several days to a week for a fish to acclimate to water of DH vastly different (factor of 2 or more). If done too quickly, the fish will probably die. Your best bet is to place the fish in a very small COVERED container and add 10% of your water overnight by dripping. The next few days, add an additional 10%. DO NOT FEED THE FISH. With the small amount of water present, it can easily foul. Keep adding your water for at least 3 days and then add an equal amount of your water. Use a larger container if needed. Wait a few more days and then move the fish to your water. This is in some cases overly conservative, but should assure the safety of the fish. As can be seen, it is wise to be prepared in advance. This is a lot more effort than taken by the average “Fish Store” They have a very big price markup and tend to lose a lot of fish.


See articles on Breeding Mop spawners (Epiplatys and Aphyosemions) and Breeding Bottom spawners (Fundulopanchax.) on my internet site at

Author:  Bill Shenefelt
First publication:
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Hristo Hristov
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