Most of the pencils sport one to three horizontal lines during daylight, but they dress in vertical bars when the lights go out. This is where Nannostomus espei stands out from the other 15 species of pencils - it displays vertical bars all the time with the horizontal lines subtly visible as a background pattern.
This unique look captured my attention early in the hobby. I heard old-timers talking about when this species was available, but store owners reported that the species was no longer showing up on lists. This fish is pretty much limited to western Guyana (Rio Mazarumi and its tributaries), and I have been told that political realities have restricted the collection and exportation of aquarium fishes from this country.
A few years ago a friend of mine in New York visited an importer and found a few barred pencilfish as by-catches with another species. He purchased the espei and was able to obtain a handful of fry from a single spawning. These fry he gave to Stan Weitzman in hopes that one of them could sustain a colony. I was next in line, but alas, neither aquarist obtained any further spawns.
In late 1999 a small number of N. espei were imported and distributed sparsely throughout the States. Undoubtedly due to its limited numbers and distinctive look, the going price for this small fish seemed to be about $10 each. Through my conversations on the Internet, I found an importer who had seven specimens to sell. I paid the $10 per fish plus the air shipping. After eleven years in the hobby, I finally was keeping the barred pencilfish.
The fish arrived in February 2000 at about 1 inch in size - about two-thirds of their full size. I could only guess at sexing them. I gave them their own 20-long with java moss and driftwood, but fishroom remodeling and other projects distracted me from working with them.
This maintenance mode continued through August. By that time I had lost three specimens due to jumping. The third and most recent one out was the only fish that I had pegged as a likely female. I knew that I had to turn my focus onto this species if I wanted any hope of starting a colony.
Fortunately, I remembered seeing an article on this fish in an old issue of TFH. The article, written by the great Hans Joachim Richter, can be found in the February 1974 issue. Richter claimed that this fish is one of the easiest pencilfishes to spawn. He recommended peat-filtered water with a pH of 6 and a hardness of around 5. The temperature could be raised a few degrees over the maintenance temperature of 76. A pair will spawn around a single plant. Richter recommended a spawning grate to protect the eggs from the adults.
However, I cued on one more statement: The pair had been separated and fed well for one to two weeks. Separation of a pair during conditioning was something I always thought about, but I had never seriously practiced it. The barred pencilfish is a rare and special species. I would bar no detail in trying to spawn it. Of my four specimens, I selected the one fish that looked slightly heavier than the others. If I still had a female, it was most likely this specimen.
Over a dozen tanks sat outside while I was rebuilding my fishroom, and mosquito larvae had populated a couple of them. The espei became the primary recipients of this nutritious food. Within a week the possible female that I had isolated fattened considerably. It was definitely a "she." No espei ever got that rotund in the species tank. This suggests that they were probably spawning often in the tank - often enough that the females never filled with roe. Then again, it could have been the special feeding that the female received in the conditioning tank.
This isolation and conditioning lasted over two weeks. Then, as Richter had done about thirty years earlier, I placed a male and female into a prepared spawning tank. However, unlike Richter's claim, the pair did not spawn the following day. As with all my breeding attempts, I waited.
Three days after the pair had been reintroduced I found eggs under the grid. I left the pair in the tank for a few more hours and observed. Although the two fish swam close to each other, I witnessed no further spawning. So I removed the adults.
I counted only 17 eggs. A few twitched when my flashlight beam struck them. A couple hours later one hatchling started to swim aimlessly - typical of new characin fry. However, five or six days passed before the fry were free swimming and looking for their first food. I fed the fry green water for a few days until the fry could take newly-hatched brined shrimp. At first I could count only 4 fry, but as they got larger I counted more until I could see all 13. Once the orange bellies appeared, the raising of these fry was quite easy.
The proven male and female were each isolated and conditioned further on mosquito larvae. Two weeks later I tried again. This time the pair spawned just as Richter said - the next day. This time I obtained 25 fry.
This repeated and improved success of spawning the barred pencilfish turned me into a believer of dedicating tanks for isolation and conditioning. This lesson is now applied within my breeding room with similar successes for other species.
Faithful to this pattern I set up a spawning tank two weeks later and introduced the proven pair shortly before going to bed. I was startled the next morning to find the male floating. Apparently the carbon on my r/o system had been exhausted as its output was beginning to emit a faint chlorine smell. I assumed that chlorination caused the male's overnight death.
The female was returned to her conditioning tank. A week later I tried again, this time using one of the other two males. No spawn. Then I tried with the only other male espei. Again, no spawn. Since that time I have conducted additional attempts to spawn this heavy female with either of the other males, but I have not had success.
What changed? I can think of three things. First and obvious, I lost the proven male. Perhaps the other two males just don't have what it takes to induce the female to spawn. Less likely, perhaps the female bonded with the first male and will not mate with any other.
Second, after the second spawn my supply of mosquito larvae ended due to cooler weather. Perhaps the female needs this quality nutrition before she will spawn. This seems quite plausible to me. Now that summer is approaching, I should be able to test whether or not mosquito larvae is the missing piece.
Third, perhaps the female was damaged in the water conditions that took the life of her mate. Plausible, but I doubt if I can demonstrate this.
All of my fry have grown up to be young adults. After BAP'ing some and giving others to fellow characin breeder Mike Hellweg, I have about two-dozen left. I have not given up. As summer approaches I intend to select three to five good pairs of the pencils and condition them on harvested mosquito larvae. Once I get proven pairs I should be able to set up three to five breeding tanks all at one time, collect the eggs/hatchlings the following day or two, and raise the fry all together. This promises to be a relatively efficient way to harvest Nannostomus espei - a fish that is rare in the hobby yet desired by hobbyists.
· 1 decade ago