by Bill Pabst
Lineatus "Gold" is one of the "easier" killifish to keep and breed, and can sometimes be found in area fish stores at outrageous prices. They are usually sold under the name "Golden Wonder Killie" or the less creative "Yellow Killifish." They will eat flake food and are content to occupy the surface of a community tank. I started with a pair of fully-grown adults; each was the last one in a tank, found at separate stores but possibly from the same breeder. The male is 4 inches and the female is 3.5 inches, both of the solid body-color variety, with no vertical black stripes.
I kept the pair in a 5.5 gallon with a sponge filter and no other décor, except for the requisite tight-fitting lid. The spawning medium was a six-inch long mop of green yarn with a slightly course texture, clipped to the top of the tank for easy removal. The pair was fed predominantly on frozen brine shrimp, with occasional staple flake and frozen bloodworms. They eat with a vigorous snatching motion that is typical for surface-dwelling killies. The temperature was 73 to 76 F and I did approximately 50% water changes every two weeks or whenever waste built up. At some point I upgraded the sponge filter to an Aquaclear "Mini" power filter, with no noticeable affect on the fish behavior.
I rarely saw the pair actually spawning, but after a few days of getting acquainted there were eggs every night when I checked the mop. The male drives the female into the mop with a sideways pushing motion, and then the pair shakes as the eggs are released and fertilized. My harvesting method is to pull the mop out by one ‘lifter’ string, which is longer than the others and attached to the knot holding the strands together. I squeeze out the water and place the mop on a white paper towel, in order to see any eggs that fall off. The eggs are 1 to 2 mm in size and hard to the touch. I picked the eggs and put them in clear plastic cups, so that fungus or development of eyes would be easily visible. To discourage growth of fungus I used a very strong solution of methylene blue, about two drops per cup. I collected the eggs in batches of 7 to 10 days, letting them all soak in the chemical bath for a few more days before pouring off the blue water. I then put the eggs and fresh water in a shallow tupperware. Depending on the temperature, the eggs would start to "eye up" after about 10 days and hatch in 14. The fry are large enough to scoop up with a tablespoon or catch with a medicine dropper. I force hatched any eggs that had eyes, but had still not hatched after four weeks, by putting them in a jar with a little water and breathing into it before shutting the lid tight for a few hours.
I raised the fry in a 1-gallon plastic "shoebox" with an air line and some java moss to provide cover and microbes for snacking. I have since learned that a killie fry box works well with a little peat in the bottom to condition the water and give the fry hiding places, and a ram’s horn or other snail to clean up uneaten food and to provide food for infusoria.
The fry were fed microworms and fresh hatched baby brine shrimp. In a few weeks I transferred them to a 5.5 gallon tank. It had an Aquaclear "Mini" filter with a sponge covering the intake tube, a rock with some java moss, and a dimmed fluorescent hood. The fry grew quickly on twice daily feedings of fresh bbs or Argent’s "Cyclopeeze." The males began to develop their distinctive yellow-gold color around 3/4 inches, with both sexes beginning to show orange-red tips on fins and tail.
Now they are growing out in a twenty-high with another younger batch, and the two age groups seem to get along well. They consume massive amounts of any frozen or flake food. After a few months, the largest male is 2.5 inches long and growing.
This article first appeared in PVAS’s Delta Tale, Vol 31, # 3-4