Aphyosemion congicum Z82-17

Aphyosemion congicum is a beautiful and not commonly seen species of killifish from a limited distribution in the Democratic Rpublic of Congo.  It’s somewhat unique among killies as the base body color is yellow, gold, or even orange.  There are some dark red to black spots throughout the body and tail and the dorsal and tail fins have broad black marginal bands.  This species probably can’t be confused with any other killifish. It’s not currently common in the hobby and the Kenge Z82-17 strain is the most commonly found.  

This species is found in rainforest brooks and streams and appreciates cool water on the soft and acidic side. I currently keep my water around 120-150ppm hardness and 72 °, I don’t check pH.  I raise fry in straight tap water, which for me ranges from 225 to 350ppm hardness. 

Feeding Aphyosemion congicum is similar to most in the genus.  I feed them a range of live & frozen foods including frozen blood worms, frozen tubifex worms, white worms, black worms, fruit flies, chopped red worms, daphnia, baby brine shrimp and grindal worms.  Fry get baby brine shrimp, microworms and golden pearls and grow rapidly.  This species will take prepared foods like flake or repashy, but only as a supplement.  They will not grow quickly or spawn being fed only prepared foods, and will possibly not eat enough of it to survive.
This is a plant spawning species and breeding is fairly simple.  They can be bred using a spawning mop.  You can pick eggs and incubate them in water or on damp peat moss; incubation takes 14-21 days.  Another way to incubate the eggs is to pull the mop from the tank, squeeze out the excess water, and store in a Ziploc bag.  Keep an eye on the eggs to watch for development.  When using one of the above methods I like to keep the male and female separate for conditioning and then put them together for a day or two for spawning.  This typically gives a larger number of eggs.

Another method of spawning them is the method I learned from Gary Greenwood & John Metzger, and the method I currently use.  I fill a 2.5 or 5 gallon tank approximately half full of long fiber sphagnum moss.  Usually I will pre-soak the moss until it sinks before adding the fish.  These “natural” setups get large weekly water changes to maintain water quality.  I feed live/frozen foods daily, and these tanks always get baby brine shrimp as well.

Usually within 4-6 weeks I start seeing ¼” long fry hiding in the moss or hovering just above it.  At this point I set up an identical tank and move the parents.  The fry grow slowly and show signs of sexing out at 6 months.  Once I see a large number of fry in the 2.5 gallon and they have a little bit of size on them, I will carefully remove the moss, small amounts at a time, by hand.  Once most of the moss is out of the tank, I will transfer the entire contents of the tank to a 10 or 20 gallon tank.  At this point I start feeding the fry crushed flake, and grindal worms or chopped black worms if I have them as well as baby brine shrimp. 

I’ve kept this species on two separate occasions now, and the first time all of my fry turned out to be male.  From what I’ve heard, sex ratios skewed heavily towards males are common.  This second time I have a more even sex ratio; possibly from raising fry in straight tap water and at cooler temperatures. 


Due to the skewed sex ratio and slow growth, this species is a little challenging.  It is also pretty demanding about water quality as it will stop spawning if the water conditions are not right and take some time to spawn again even when the conditions are right.  But it’s also very beautiful and uniquely colored and worth keeping around.