By Donna M. Recktenwalt
A major fascination about many of the killifish we keep is the way they reproduce, but breeding them can be a lot of hard work, especially for those species that require long incubation times.
What if you want to keep and breed killifish with a minimum of effort?
With some species of plant- or mop-spawning fish, it can be done.
Start out with any size tank, densely planted or well filled with fine leaved free-growing plants such as hygrophilia, hornwort, watersprite, or java moss. Add a slow running foam filter, either external or internal. Introduce the fish, feed well and do regular partial water changes; then watch fry of various sizes begin to appear.
Sound too simple?
For some species of killifish, particularly the annuals, this approach would be next to impossible; for others it is nearly ideal: the fish fertilize the plants; the plants host a colony of microflora and fauna and provide sites for egg-laying and cover for the fry; which feed off the microscopic life.
Supposedly many European killikeepers routinely breed their mop-spawning killies this way.
“I have a 20 gallon high tank that is about 3/4 full of java moss,” says Shane Essary. “I put the pair of fish that I want to spawn into the tank …. Pretty soon the tank is full of babies that get really big without having to feed them [heavily on] baby brine shrimp.” Shane has used this method successfully for A. scheeli. For A. abacinus, hesubstitutes mops for the java moss but still lets the eggs hatch naturally.
“I have had good luck with A. celiae celiae, letting them breed in a well planted tank and not picking eggs or rescuing fry, also with E. dageti, using java moss,” reports Harry Kuhman.
Donna Recktenwalt has been raising A. chaytori Ngabu and A. mirabilis Takwai in separate densely planted colony setups. “I get as many fry from the tanks as I do from collecting and incubating the eggs,” she says. “I regularly find fry of various sizes in with the adults. The parents seem to ignore them entirely.”
“Almost all my Epiplatys annulatus will allow young to survive,” says Lee Harper, “and a trio of Pachypanchax omalonatus has shown tolerance for young fish. Diapterons in general will not.”
“I’ve had this experience [tolerant parent killifish] with E. fasciolatus (big time! we’re talking hundreds from four adults in a plant and algae choked 40 gallon tank), E. dageti, and (to a much lesser extent) A. australe,” says Richard Sexton.
Other species that aquarists report have shown tolerance for their fry include A. ogo ottogartneri; A. coeleste, A. aureum, and A. citripinnis.
For particularly troublesome species, a variant of this method has been used successfully by some. Instead of simply filling the tank with plants, pack it nearly full of java or sphagnum moss, leaving only a little space around the outside for the adult fish, and a small depression at center top for the fry. The parent fish will spawn in the java moss and the hatching fry will gravitate to the depression at center top, where they can easily be removed for growout in a separate container.
This doesn’t always work, but may be worth a try for fish that are highly aggressive, or that regularly prey on their young.
— G.C.K.A. Newsletter, December 1997 and March 2002