By Don Kinyon
Every once in a while a fish is brought into the hobby that makes even veteran fishkeepers take notice. In 2004, Lance Peck was collecting in Peru and netted a Corydoras catfish that hadn’t yet been introduced into the hobby. As it turns out, this was one of those “take notice” fish.
Not yet described at this writing, CW016; Corydoras teniente, or the “Lieutenant Cory” has been one of the “gotta have it” fish of catfish addicts for a few years. It’s not garishly colored, but a very attractive fish. The majority of the fish’s body is a light bronze color and there is a large black/green spot just below the front spine of the dorsal fin that continues almost to the pectoral fin. In front of the dark spot is a smaller area of iridescent gold that catches light as the fish moves. Males grow to 2 ¼” while females get slightly larger.
This is one of the more streamlined body Corydoras, giving one the idea that it most likely comes from faster moving waters. Its habitat is the drainage or the Rio Madre de Dios, in fairly fast moving streams, the water being heavy in tannins, low in pH and very soft. It’s often found in the same streams in which Corydoras weitzmani is collected.
Like many of the more desirable fish in the hobby, supply-and-demand put the price of the C. teniente way out of my budget. I’d only seen pictures of these fish and hoped that in time the price would come down far enough for me to add them to my fish room. As things worked out, I was talking with Ian Fuller at one of the Catfish Conventions (not sure which one) and he gave me one of his prints of the fish (still prominently displayed in my fish room). He gave me some information about the Cory and said “You need to get this fish; talk to Frank”. I’d been trading fish back and forth with Frank Falcone for a couple years and we worked out a deal for me to receive a group of his young fish.
A few weeks later, ten fish made it to my house via UPS and all but one were in good shape. One of them got caught up in the folds of the bag and didn’t survive the trip, but nine of them were active and healthy as soon and they were put into the tank. Their first home was a standard 20 gallon long aquarium with two sponge filters and a couple pieces of bog wood for them to hide under. There was no added lighting and with the tank on the bottom level of a rack, not a lot of ambient light either. Water was a mix of well water and rain water to keep the pH around 7 and the TDS to less than 100 PPM. The temperature stayed between 68° and 75° F with no additional heating.
This Cory doesn’t seem too fussy about food at all. They ate pretty much anything that was offered: flake, freeze-dried, frozen, and live food. They are particularly fond of live black worms.
Corydoras teniente doesn’t grow as fast as some of its cousins, but the young fish grew at a fair pace and in 18 months or so were near full sized adults. Around that time, during water changes, I noticed the fish would all swim directly into the stream of water from the hose as the tank was filled. They really seemed to enjoy it! To accommodate their love of fast moving water, a powerhead was added at one end of the tank, directed down the front glass. The catfish seemed to like the idea and they were much more active after that. Around that time I found some pictures on line of the habitat the fish came from showing a stony creek bottom so I added some round lake stones at the center of the tank and removed the bog wood. When the fish were fed, food would get in between the rocks and the fish would push around the stones to get at any bit of food. I’m not sure if this is how they act in the wild but it was fun to watch.
A second powerhead was added to the first, pointed in the same direction and this brought the current to nearly a whirlpool level. At the same time, just rain water was used at water changes instead of the mix, and the pH dropped to six, TDS to around 20 PPM. After a day or two, I began to think that maybe the current was too strong, although the fish showed no distress, and was considering removing the second pump. Before it came to that point, the fish began to spawn. All the visible eggs, about 50, were on the front glass directly in the current flow. These were removed and placed in a hatching container with tank water and a drop of Acriflavine. In a day’s time, a few eggs showed signs of fungus and after three days, all the eggs were covered with filaments; all gone bad.
The breeding set up had worked once, so it was left alone for the time and while doing water changes two weeks later, I noticed two young fish hiding in the stones near the center of the tank. With the amount of current produced by two powerheads, the sand that had once covered the bottom was now in the center with the stones and young fish were almost invisible unless they moved. Evidently, removing the eggs was a big mistake! In the next few weeks there were four more spawns, most of which were about the same size as the first, but they produced very few fry. The eggs of these spawns were left on the glass in the current stream and allowed to hatch into the breeding tank without interference on my part. This produced a total of nine young fish.
The Internet is great for information, but aquarium society meetings and conventions are the best! I was talking with Eric Bodrock at the 2016 Catcon and he gave me some great advice on keeping Corydoras eggs from becoming hairy little balls of fungus. Fungus will spread from bad eggs to good ones if they’re touching, but it won’t easily spread through water with some kind of deterrent added. He also gave me a bag of Alder cones to try as an antifungal agent instead of artificial solutions.
For the next few spawns, the eggs were removed from the side glass with a razor blade and separated as well a possible. I found that trying to separate them with the razor blade destroyed more eggs than gently pulling them apart by hand. Using this method, it’s almost impossible to produce groups smaller than two or three eggs, but at least they can be cut down to very small numbers. These groups of eggs were spread out into a 5.5 gallon tank with heavy aeration and a shallow layer of sand on the bottom; water same as the breeding tank and a couple Alder cones.
This time around, there were three spawns in three weeks and all eggs were put into the same small tank. Some of the eggs turned white and were visibly bad, but quite a few darkened and eventually hatched. In all, about twenty-five youngsters were produced through this method; not a great average, but better than previous tries.
At this writing, the group of young fish is around five months old and has been moved into a larger tank with the adults. The new tank is thirty gallons and set up the same as the original breeding tank with two powerheads and some round stones in the center. So far, the original group has not produced eggs in the new set up, but the fish are starting to exhibit spawning behavior.
Corydoras teniente is still found only rarely for sale and the price is often too high for many hobbyists, but they are a very attractive addition to anyone’s collection. Though more difficult to spawn and raise than many Corydoras, it’s quite possible, with a little luck and perseverance, to be successful with them.