Genus of Commonly Available Killifish
Killifish doesn't mean 'killing' or "killer" fish! Neither does it describe the aggressive behavior of some vicious piranha species (Jr. Jaws), nor does it describe the result of what the hobbyists experiences in attempting to keep rare and exotic tropical fish. Killifish are not that difficult and with a little research and reading, someone with about one year of experience, can easily keep and breed killifish. The difficulty with killies certainly isn't in keeping them alive and spawning daily under normal aquarium conditions, but rather harvesting eggs and raising very tiny fry, feeding with live cultures of greenwater/infusoria, miciroworms, vinegar eels, and newly hatched brine shrimp nauplii.
Killifish (Cyprinodontae - toothed carps) are a very diverse, many gorgeously colored, interesting group of freshwater minnows found all around the world and mainly in the range of the equatorial regions. Killifish are the egg-laying cousins to live bearing fish such as mollies and guppies. There are about 350 species of killifish. Like their live bearing counterparts, killifish are usually mosquito larvae eaters. Many killifish species are as brightly colored as salt water fish and have incredible finnage, as you will see as you read and click further.
Some killies, known as annuals, spawn every day, because in nature, when the pond dries up, the eggs go into a hibernation phase known as diapauses. When the pond fills with the rains from the next season (sometimes 6 months) the eggs hatch and it isn't long before the whole pond is filled with killifish. Although killifish are noted for this drying period, not all killifish are annuals, that may only live 1 or 2 years, but given the right conditions, killies generally spawn every day 2-3 eggs or more.. Killifish that come from areas that are wet year round, such as streams, ponds, and swamps, tend to live longer, some as many as 5 years or more. These plant spawning killifish are also usually the easiest species to be a first killifish.
Killifish are divided into three general breeding groups of annuals, semi annuals, and non-annuals (plant spawners).
In the wild, the annuals live for, usually, a single season in temporary ponds and swamp areas, until they dry up to moist mud and vegetation, such as decaying leaves.. Annual killifish are all substrate (peat) or bottom spawning fish. With the coming of the rainy season, the annual killifish hatch from eggs deposited in the mud and decaying leaves, the result of the daily spawning of the previous generation. Spawning is done every day, just in case in the next rainy season, the first rains are insufficient to fill the pool. In this way, hatching times of the next generation are thus spread out over time. Species of annual killifish therefore grow and mature quickly, so they can repeat the process before the ponds dry up again, between rainy season.. Annuals are substrate spawners therefore need to be bred with peat moss method, with the eggs stored in the peat, until the hatching date.
Semi-annuals live in areas which sometimes dry out to moist mud, but at other times retain water throughout the dry season. They are therefore substrate (in the mud, leaves, etc.) spawners and tend to live a little longer than the annual species of killifish. Semi-annual killifish can be water incubated (i.e. many of the species in the Fundulopanchax genus), but also do well with higher hatching rates, if allowed to be stored in moist peat for 30 -60 days. This is particularly true of species in the Callopanchax group. After this 'drying' period (never really completely dry, very moist storage) put the peat and eggs in water and "presto!" baby fish hatching out over the next few days. Semi-annuals generally tend to be substrate spawners, meaning they will spawn in peat moss, Java Moss or in spawning mops placed at the bottom of the aquarium.
The non-annuals, such as the Aphyosemion genus species of killifish, live in permanent bodies of water and, in some cases, will live for up to five years. These species, although there are some more difficult and require more to keep, breed, and raise species (i.e. Cognatum); are usually a good choice for a first killifish. Many seem to have chosen Aphyosemion Australe as their first killifish. The non-annuals, or plant spawners, can be bred using the spawning mop method for higher yield and with water incubation of the eggs. Most non-annual killifish eggs hatch on an average of 21 days or so.
The species and genus of killifish within the same breeding categories vary dramatically from continent to continent. The annuals of Africa, mainly killifish in the Nothobranchius, vary in shape, size, color, and the number of various species in the genus from the annual Austrolebias, Autrolebias and Sympsonichthys species of South America. These types of differences and variations are to be found in other genera throughout the world. Another example is the Aphyosemion genus of non-annuals from African, which has two sub-genus, Chromaphyosemion and Diapterons.
The classification of killifish continues to undergo many changes, likewise there are variations of coloration in populations/locations of the same species.. For example, Fundulopanchax Gardneri, the fish in our logo above, was formerly known as Aphyosemion Gardneri. The same is true for Fundulopanchax Arnoldi and the Blue Gularis, both formerly classified in the Aphyosemion genus. The naming of fishes is conducted in accordance with strict rules as laid down by an international body called the International Commission of Zoological Nomenclature. These academics, scientists and taxonomists conform to the rules and decisions of the commission whose rulings are final and indisputable. So, it seems wise to let these folks hammer this out between themselves, because they like to do it and it is important that species of killifish remain genetically pure in the aquarium hobby, meanwhile we enjoy raising some of the most beautiful freshwater fish in the world, which rival the color and fins of saltwater fish.
The genus of killifish are determined by the location the species within them are found as follows:
Killifish species generally should not be mixed in the same aquarium. Not only because of the risk of territorial battles, but to keep genetic lines pure. Killifish of the same species, but different populations should be mixed, neither should killifish belonging to the same genus, certainly the same sub-genus such as Chromaphyosemion. Therefore, as a word of caution, obtain your killifish ONLY from a reputable and informed breeder, so that you are sure your line of killifish species is pure and is not a hybrid of several species. This way you will be sure the fish that you breed and raise are the same species and location/population and genetic make-up of their parents. However, I have housed Aph. (Chroma) Splendeure with Aph. Australe, with no adverse effects and reproductive isolation (only harvesting eggs from separated pairs/trios), as each species kept to their own place with the Splendeure happy at the top in the floating plants and the the Australe happy with the mid to bottom strata. I have also kept Aph. Bivitattum-Funge in with guppies with no adverse problems, bar some unlucky baby guppies. If you choose to breed and raise killifish, only distribute killifish you know are from the same species and population.
Although there are many very good species for beginner killifish, notably, Aphyosemion Australe, Aphyosemion Bivitattum, and Fundulopanchax Gardneri, those wishing to raise and breed killifish should have about one year experience in general aquarium keeping, to understand water chemistry, food cultures, and general aquarium practices and their reasons. Review of this basic literature, review of the killifish literature, information and links found here at Tropical-Fish.net and joining Aquarium-Club.org is highly recommended for those interested in killifish. Likewise joining a local aquarium society is encouraged.
Although killifish are generally easy to raise, the difficulty being only in trying to raise very tiny fry, albeit some survive in well-planted aquariums, there is one word of caution about killifish. They are known to jump out of the aquarium. Even through the smallest of holes in an aquarium hood, such as where the filter intake is located, killies will find a way out. Therefore, wrapping plastic wrap to cover all holes in the aquarium hood is highly recommended, lest one morning you wake up to find your rare and gorgeous killifish on the floor dried up, after they took what I call "The Dramatic Darwin Leap".
Of the three (3) suggested first killies, Gardneri usually proves a good choice, because of the variety and populations/locations of this species. Gardneri eggs, as is true for all killies, can be easily and successfully shipped in the mail, or by any package service. Because of the time it takes for embryos to develop and hatch, usually around 3 week, even the more so with annuals shipped in peat, killifish can be easily and successfully shipped around the world. This shipping of eggs, although shipping fish is equally as easy, is one of the other neat things about keeping killifish, in addition to their diversity and stunning beauty.
Although it is fun to get a baggie of peat moss (mud) that we put into a hatching tray of seasoned water, many killifish fry are small and require live foods such as newly hatched brine shrimp nauplii and even smaller foods such as nematodes (microworms & vinegar eels). Many aquarium hobbyists who raise/breed killifish prefer to have pairs, trios or a group of young fry beginning to sexually differentiate, rather than to receive eggs and wait for these to develop. Either method, eggs or live fish, works well and it is pretty much the preference of the hobbyist, if they would rather receive live fish or eggs.
We have listed some of the species of killies most commonly available from the Aphyosemion (including Chromaphysoemion and Diapterons), Epiplatis, Fundulopanchax and Nothobrachius genus. We will be adding more information per each species, (feeding, breeding and general care) in the near future.
Until that time, please feel free to check out the links to the attached pages and for more information about Killifish, please check out our friends' web sites below.
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