For those who breed killifish, there are always challenges ahead. In this occasional column, we’ll highlight a few breeders and their proven techniques.
“I breed killies as trios in gallon pickle jars,” says Zavier Burgos of Orlando, Florida. “It works great with the spawning mop and the fish, because all they do is breed. They are not looking for each other, they know of each others’ presence in the jar and they go for it.”
This jar method works well for a number of the smaller species and often yields large numbers of eggs – “I have gotten from a single pair of A. striatum 175 eggs, and all but one hatched.” – but it is more time intensive since you must supervise the breeding setup.
“I condition the fish for 2-3 weeks, depending on the fullness of the female,” says Zavier. He separates the sexes during this conditioning period, and feeds them up to six times a day with a variety of foods, including 40-46% protein flakes, spirulina flakes, live foods, and freeze dried tubifex and bloodworms.
About 25% of the water in the conditioning tanks is changed every other day. Xavier uses rainwater for all his breeding tanks, aged for at least two weeks before use, then filtered for a day through peat and for two more days over charcoal. “The peat has hormones that induce breeding, and it disrupts the carbonate hardness in the water so you can adjust the pH more easily,” says Xavier. For each breeding setup, this pretreated, aged water is put into a gallon size pickle jar with a spawning mop and the fish added.
“Don’t use lighting while breeding,” cautions Xavier. “Just place the jar in a corner at eye level.” You will be able to see the fish, but not the eggs. Breeding is over when you see no more movement from the fish. This may be as little as 15 minutes to two hours or more, depending on the species. When breeding is done and the female is tired, be certain to remove her; the male can be left for another hour or so. If all has gone right, “you should have too many eggs to count and all [of them] fertile.”
— G.C.K.A. Newsletter, March 1999