Beginners’ Corner
Keepin’ Killies – A Primer
Beginners often ask, “what does it take to keep killies?”
Nothing more than it takes to successfully keep any of the more common tropical fish.
Although there are some species among the killifish that are very difficult to keep and breed, there are just as many that are fairly simple to maintain. All, however require the same basics as any other fish: clean water, a suitable covered container, and food. Depending on the species of killifish you wish to keep and the conditions they prefer, the following may or may not be required: a suitable substrate; lighting; filtration oraeration; and plants or other appropriate cover.
Water
Like all other fish, killifish require good water. In most cases, well aged dechlorinated tap water works just fine. Many aquarists swear by such commercial products as Stress Coat for neutralizing the chemicals found in municipal water supplies. For some species, soft water is a prerequisite. This can often be provided by mixing clean rainwater or reverse osmosis (RO) water with conditioned tap water.
Containers and Covers
Accommodations for adult killies can range in size from small to very large, depending on the size and the number of fish. Many killikeepers keep their fish in 5, 10 or 20 gallon tanks, but killifish have been successfully bred, raised and maintained in goldfish bowls, tupperware containers, plastic dishpans, plastic storage boxes, glass pickle jars, and various other containers made of suitable materials. Be certain to cover your killifish container. Covers help to reduce temperature fluctuations and evaporation. More importantly, many killifish are jumpers. Even the best breeders have been dismayed to walk into their fishrooms and find that prized killies have become “crispy critters” on the floor.
Foods
Unless you’re trying to breed your killies or have a particularly finicky or delicate species, most require no special diets. They prefer and will do better with a liberal assortment of live foods, but will do quite well on the flake and frozen foods available in most aquarium stores. If you’re trying to breed your fish, the greater the variety of food, and the higher the percentage of live or frozen food, the better.
Substrate
Whether you have gravel on the bottom of your killie tank or not is a matter of personal choice and whether or not you want to include rooted plants, which use the gravel as an anchor. In addition, many killies prefer the calming effect of having a “bottom” to their environment, and show their colors better with a dark substrate. For fry tanks, bare bottom tanks are often preferred, since they are easier to keep clean. If the species you’re keeping prefers soft water, you may want to use a thin layer of peat moss on the bottom of the tank, which will also help to buffer the water and keep it soft.
Filtration and Aeration
Most but not all killifish tanks include some type of aeration or filtration. Most commonly seen are airstones to keep the water in circulation, or simple foam filters, which provide both good mechanical and biological filtration. Outside filters and undergravel filters are also successfully utilized.
Lighting and Plants
Light levels in killie tanks are dependent on the species of fish you wish to keep and the live plants you may choose. Some fishand some plantsdo well under subdued light conditions, while others require high light levels to do well. By matching the requirements of the fish and those of the plants, successful killie tanks can be maintained under most light conditions.
Plants are a matter for personal preference. If you’re just keeping killies for their visual beauty and the joy of observing them, plants can be of any variety you prefer that is decorative and hardyevenplastic, if you like. If you’re attempting to breed the fish and hope to find fry in the tank, free-floating fine leaved plants are preferable, both as security for the adults, as a place for them to lay their eggs, and as cover for the fry. Java moss, which thrives under almost any light condition, is perennially popular; as are water sprite and hornwort, which require bright light conditions.
Breeding
There is no doubt that some species of killies truly are difficult to breed, and that few killies can be raised in large numbers with minimal effort, as many of the commercially important species can. However, breeding killifish can range from the ridiculously easy to the extremely difficult, depending on the species and its requirements, local water conditions, and the attention paid to detail in your fishroom. Some of the Fundulopanchax and Aphyosemion species will happily surprise their owners with unexpected fry in their tanks. Others, such as some of the Cynolebias and Nothobranchius species, require particular spawning media and long dry storage of their eggs before fry can be produced. Few commercial fish breeders are willing to devote the time, space and effort required to meet the special needs of killifish breeding. Fanciers can, and often do.
Buying and Selling
The commercial market for killifish is limited, since few aquatic dealers know much about them. Some local aquarium shops do seek suppliers, and some killikeepers help support their hobby by selling to them. However, most killifish are sold to those within the hobby, either through the Fish and Egg Listings in the American Killifish Association’s Business Newsletter, or at club meetings and shows. One advantage held by killifish over many other fish species is that their eggs can be easily stored and shipped, making both local and long-distance sales easy. If you’re looking to buy, joining the AKA and/or your local killifish club is the most effective way to locate and acquire stock.
— G.C.K.A. Newsletter, September 1997