Flush with the success of multiple spawns from my bristlenose plecos, I decided to apply what I’d learned to a more difficult pleco. I bought two separate groups from Pembina Petland: a group of four in April of 2004, and another group of 4 about 6-8 weeks later. I spent the next 6 months conditioning the fish, and trying to sex them, (which is very hard with fish that hide a lot ). The fish were housed in a 50 gallon bare-bottom tank, with an air-driven sponge filter, a powerhead-driven sponge filter, and an Aquaclear AC-300 hang-on-back filter. This may seem like overkill, but they prefer alot of current-some say it’s necessary to get them to spawn. The tank temperature was approximately 26-28 degrees celcius. The fish were fed mainly on frozen Hikari bloodworms, Hikari sinking carnivore tablets, and Hikari algae/spirulina disks. While this may seem like a commercial for Hikari, the fish really do seem to relish their food.
Cave Design
After a few months of heavy feeding I began to think about cave design. I tried caves made out of coconut shells, clay flower pot dishes, and (after reading of other’s successes on the internet) finally settled on long rectangular caves made out of ceramic tiles. The caves were made slightly taller, almost 1.5 times the width, and twice as long as the adult fish, with an end cap so that the male would be able to keep the female in the cave to spawn with her.
Composing the breeding group
By November, I decided that perhaps I had too many fish in one tank for them to feel comfortable enough to pair off, so I removed them to pails to try and sex them. I’ve been told that you can sex them by looking at them from above…the females especially when gravid will look much more streamlined with a pointier face, whereas the males will have a more blunt appearance to their face (and will never get gravid, of course-though I have seen some pretty well-fed males). Another difference between males and females, is the formation of a “feathery growth” around their gill area (interopercular odontodes) which is often much longer in males. After making “best guesses” on the fish, I took two of the fish into Petland for store credit, and ironically, I took what was probably my best bet to be a male. I went back the next day to get him, feeling a little embarrassed. After adding more caves to the tank, I re-doubled my efforts to get them to spawn, by playing with the hardness of my water, and aiming the water current at different areas of the tank. I also tried to simulate the dry season by letting the tank conditions go a bit and not changing the water. A week or so before Christmas, I did a really big water change on the tank bringing the hardness back UP ( my water is normally Ph 7.5, Conductivity in the 600-700’s depending on time of year).
Spawn
I don’t believe that the softness or hardness of the water played much of a roll in getting them to spawn. I think what was necessary was the change in water parameters to “trigger” the spawn. Soon after that I noticed the male seemed to have a female trapped in the cave. On Christmas eve he released her and was sitting on a spawn of eggs. I began to see the first wigglers around the 29th of December, and placed the ones that had escaped the breeding cave in a netbreeder with an airstone. Shortly after that I removed the rest of the wigglers from the cave and put those in the breeder net as well. Within a week they had absorbed their yolksacs, and reached a length of almost a centimeter, showing the beginning of some pattern. I began to feed them algae wafers and sinking carnivore tablets, which they thrived on. They grew to almost 2 centimeters in the first 2 months and then growth slowed down quite a bit.
I’ve tried both removing the wigglers from the parents to raise, and allowing the parents to raise them, and I’ve seen smaller numbers survive from the parent raised spawns. I feel this is because the fry don’t get enough food spread over such a large tank area. Whereas, in the breeder net, I can target feed them while still having the advantage of a large tank for water quality. I’ve since had several more spawns with no effort or special attention on my part.
Source: Aquarticles.com (no longer available)
