Tanganyikan Pearl Killifish
Tanganyikan Pearl Killiefish (backlighting), Photo by Darrell Ullisch
The Tanganyikan Pearl Killiefish, Lamprichthys tanganicanus, is the most delicately beautiful fish I have ever kept. The iridescent blue dots on a reflective pearl background are extremely striking. There is also a lacy yellow pattern that comes and goes depending on the angle of reflective light. In fact, observers will watch and study this fish much longer than any other species in a tank because the colors and patterns are constantly changing as it swims, and it is a very active fish! The males, especially the dominant male, have most of the color, although the females have a slight color pattern over an attractive silvery-pearl background. Males reach up to 6 inches with females slightly smaller, although I have never seen them that large. A 4 inch fish is quite large and my fry began laying eggs at 2 inches, about 6 months of age. By the time they reach 3 inches the males are in prime color. The body shape is long and slender. They are an extremely fast fish that can jump, so cover their tank well! They are a very peaceful fish with most of their aggression between the males. These fish seem to prefer schooling together. I can only describe their appetites as gluttonous! They eagerly eat flake food, scraped liver, frozen brine shrimp, and live foods like daphnia and white worms. I tended to feed them too much, and was surprised at how much food they could cram into that slender body!
The Tanganyikan Pearl Killiefish is found only along the rocky shores of Lake Tanganyika in Africa, at depths of 3 to 15 feet. Medium hard to hard water with a PH about 8.5 at a temperature of 73 to 77 degrees is recommended. I kept and bred them in Lake Michigan water with a thin layer of dolomite gravel on the bottom to add some hardness. A sponge filter in a small pan covered with large gravel was used to filter and collect loose debris. This filter can be removed and cleaned without changing the water chemistry in the tank. These fish are noted for their delicate sensitivity to water conditions, which I feel is somewhat undeserved. Anyone who has kept shell dwelling African cichlids knows that large changes in chemistry or pollution level can shock them. If you keep to water changes of 25% or less and don’t allow pollutants to build up (e.g. with undergravel filter), you should have no problem keeping this fish. In fact, I kept and bred mine in the same tank with several Lamprologus multifasciatus and they got along fine. For quite a while I was keeping them in a tank with a dolomite undergravel filter and they seemed to get along well. The trouble began when I stirred the gravel and used a power filter to pick up the debris. Moving these fish to another tank didn’t seem to work well either, unless I adjusted them to the new water very slowly. The key seems to be stability of water conditions, and the less they are moved, the better. I would recommend a 20 or 30 galon tank minimum with lots of swimming room. Do not overcrowd them. 4 or 5 3-inch fish would be maximum for a 20 gallon tank. I keep them in subdued light in a plant free tank to breed, although they show off best in a large lighted and planted community aquarium. 25% water changes once a week seems to be plenty. The Tanganyikan Pearl Killiefish is long lived, and it takes the males over 1 year to reach full color. They spend most of their time near the water surface but will pick up some food from the bottom.
Breeding the Tanganyikan Pearl killiefish is relatively simple with only a few modifications from breeding most killies. They are continuous spawners with 1-3 eggs laid per day from a smaller pair. The eggs are extremely large, 3mm, and clear. If you have ever picked tiny rainbow or Nothobrachius eggs from a mop, you will really appreciate these eggs! Most articles state that they lay their eggs in the rocks on the bottom, although I have found that they will also lay them in a dark colored nylon mop. The problem is that the eggs are non-adhesive and fall out of the mop. To catch the eggs I use a plastic pan underneath the mop with a layer of ½ inch gravel in it to protect the eggs. Fish with appetites like theirs, I do not trust! If this mop and pan is all the “structure” in the tank, virtually all the eggs will be laid there. I usually find about half the eggs in the mop and the rest in the pan. After shaking the mop, the pan can be removed and examined for eggs. They are not prolific, but you should be able to get plenty by picking the eggs every 2 days. I place the eggs in a quart pan of tankwater and add one to two drops of methylene blue. The eggs take 22 to 24 days to hatch so I place a slow bubbler in the pan to maintain oxygen content. The fry are 10mm. long when hatched and are easy to feed as they will immediately take newly hatched brine shrimp. They grow quickly the first 3 weeks with plenty of live food and room, then growth slows somewhat. I had bred 3 generations of this beautiful fish and then lost all but one of my breeders (you guessed it---I tried to power clean the gravel!). I am now in the process of trying to locate more of them for breeding stock.
The most desirable aspect of the Tanganyikan Pearl Killiefish is its’ striking, constantly changing color and pattern. You could take 100 successive photographs of this fish and no 2 would be alike! I highly recommend it for even those breeders wanting a challenge. And for those who have kept and bred both African shell dwellers and killiefish, it should be doable. I understand stock in this fish is quite limited now. Let’s not let this beauty get away from the hobby!