Killifish are a diverse group of small fish with a worldwide distribution being found on all continents except Australia and Antarctica. There are both egglaying and livebearing killifish, but we will only concern ourselves with the egglaying types. One of the interesting aspects of killifish biology is the ability of some species of killifish to lay resting eggs that are resistant to desication. This has opened up several habitats that only these interesting fish can live in and has led to these species being called annual killifish. The common mode of reproduction is the laying of eggs that normally hatch in about a week or so that need to be water incubated. There are several types who’s eggs can be either water or dry incubated.
Here I will cover both modes of reproduction and list several killifish of each mode that are both colorful and easy to keep and breed. We will begin with what are commonly called the plant spawners. The peat spawners require a little more effort and some patience when dealing with their eggs as a few weeks are required for their developement. I will also mention two of my favorite switch spawners that I have both water and peat incubated.
The basic plant spawning setup can be of several ways. Probably one of the easiest is a bare tank with a small corner or sponge filter and a place for the females to spawn. Water type would depend upon the species as some killifish such as the Aphyosemion of west Africa take soft slighty acid water whereas Aphanius from the Middle East live in akaline and sometimes salt water. Size of the aquaria for most plant spawning killifish can be small, from two to ten gallons. A permanent setup can be used with lots of live plants such as water sprite or hornwort. Size of these aquaria can and should be larger than a setup for a single pair although I have had some species live with their fry in a 2 gallon tank. My favorite size permanent setup is a 30 gallon, but a ten works fine for many Aphyosemion species. Most killifish breeders use an artificail spawning medium for their plant spawners. I use an acrylic type yarn that I turn into mops. This is accomplished by winding a green or other natural shade of yarn around a book, tying off one side and cutting the other, and there you have a new place for the fish to spawn. Boil the mops several times and rinse well to remove any oils or dyes from the yarn. The fish will use the mops to spawn in and the eggs can be collected daily. Place them in a small covered container and you can watch the embryos develope. Fry are born predators and many can eat newly hatched brine shrimp at hatching. Growth of fry in many cases is quite rapid and many can be sexed at 6 months. Regular water changes aid in rapid growth of the fry as well. Temperatures most killies can be kept at are 68-72 F.
Killies I recommend for the new killifish keeper wanting to keep plant spawners are both handsome and easy to keep.
Aplocheilus lineatus is a handsome plant spawner from India. These fish grow to 10 cm and males can be aggressive. Males have green to blue irredescent scales and markings in the fins. Fins are yellow with red. They are prolific spawners laying large eggs. Eggs are easy to collect by gently lifting them with the finger tips. Place them in water from the parents tank. They reqire about a week to ten days to hatch. Fry are large at hatching and if well fed grow fast. The adults should be well fed with a variety of live and frozen foods. And these fish are jumpers, so a tank cover is essential. Due to their larger size and aggressive nature I recommend a ten gallon aquarium or larger. These killies can stand a range of pH from slightly acid to slightly alkaline.
Aphyosemion australe is a very colorful killifish that comes from the coast of west Africa especially Cameroon. It does very well in a five gallon tank. The males come in a natural dark form with the fins being edged in white, The males tail has a distinct lyre shape giving this killie one of it’s common names, the lyretail panchax. There is also an aquarium variety called the gold lyretail which lacks the dark pigment and is more orange than it’s normal wild types. These fish require a soft slightly acid water as they come from the rain forest of equitorial Africa. Eggs and corresponding fry are smaller than Apl. lineatus, and they require a smaller starter food such as newly hatched brine shrimp nauplii. Fry growth is good and males start showing their colors early. Feed the adults a wide variety of live and frozen foods. They are especially fond of mosquito larvae. These killies do well in a five gallon aquarium set up as described above. Lyretails also do well in a planted permanent setup.
Fundulopanchax nigerianum is a beautiful killifish that comes from Nigeria and west Cameroon. These beautiful killifish grow to 7.5 cm and males can be stunning. Basic color is a metallic blue in the body and fins with many red to carmine markings. Fins are very distinct with a red submargin band and yellow to orange marginally. There are many locations available to the hobbiest. These killies are prolific spawners that also use a mop. They like the mop to be lying on the bottom. Eggs can be collected with the finger method and they can be stored either in water or in damp peat. Developement time is about the same, three to four weeks. Eggs in peat are rewet in a shallow container with about 3 cm of aged water. Fry growth is rapid and males start showing themselves several weeks old. Use newly hatched brine shrimp as a first food. These fish can be very aggressive, so hiding places are needed for the females. I like larger size aquaria for these fish, from ten to thirty gallon. Water should be soft with a neutral to slightly acid pH. These fish need a variety of live a frozen foods to be tip top in color and egg production. Water changes also stimulate spawning, especially fresh rainwater.