When the novice aquarist has mastered the basics of fish keeping – keeping the animals alive – they will often take the next step in the hobby: breeding. Breeding can be an exhilarating and profitable endeavor. Our feature this week will focus on breeding the Bristlenose Plecostomus.
Choosing what species of Bristlenose is a good starting place. Odds are good that your local fish store carries at least one species of Bristlenose. This makes them easy to obtain and also provides you, the breeder, with an outlet to sell the your fry once you have raised them to an appropriate size. If your store is getting wild caught Bristlenose plecos, then the tank could be mixed with several different species of Bristlenose. Look for uniformity amongst the fish. If you're fortunate, the store will be stocking captive bred Bristlenose - this makes compatibility much easier since all you'll need is a male and female. Sexing them is as easy as looking at their faces. Males have a quite intense bristle structure on their face that can go up onto their forehead, while females usually only have some small bristles right on their lip line if any at all. As they age this feature will become more apparent. If they are too small to sex, buy a group of 4 to 6 and grow them out for several months. There is nothing more disheartening than growing up what you thought was a pair, only to find out otherwise and you've got to start a 6 month process over again.
Building a home that will "set the mood" for your plecos is important and quite simple. For breeding, you should start with a minimum tank size of 20 gallons. A "20 long" is preferred, as it provides a larger footprint, but the standard 20 gallon is also sufficient. Standard heater and lighting can be setup at your discretion, but when choosing a filter, there are a couple important considerations. First, you will want to over-filter this tank since you will be dropping a larger quantity of food than you would in a normal scenario. Second, you do not want to have an intake that is unprotected. Fry can be sucked into a filter and lost forever. Therefore, it's highly recommended that you cover the intake with a net, sponge, or piece of pantyhose. If you are setting up a new tank, using media, such as gravel from a tank that is already established, can jumpstart the cycling process.
Tank decor is another factor that you may use your discretion, but you will need to provide a spawning cave. You can either make one, for example out or a terracotta pot, or buy a pleco spawning cave online. Choose a cave where the opening is about 1.5 times as wide as the pleco itself.
Once you've got a tank setup and a pair of plecos, the process can begin. You need to start feeding much more than normal and higher quality foods to condition them to breed. A mix of algae wafers, earthworm sticks, frozen blood worms, zuchnini, and green beans are all excellent dietary options. You want your plecos to be chowing down for about 3-4 hours a day making certain to remove any food that goes uneaten. Doing a water change of about 30% weekly will help to keep water parameters in line as well as spark natural triggers that coax the fish into breeding sooner. During this time regular filter maintenance is a must as you will be feeding more than usual.
When the pair is around 6 months old, they should start to spawn with the aforementioned setup. The male and female will enter the spawning cave. The male will trap the female inside. She will lay her eggs and he will fertilize them. She will then be let out of the cave and the male will stand guard while the eggs are gestating; usually with this head sticking out of the cave's opening. He will spend many days fanning the eggs inside the cave to bring them fresh oxygenated water and keep debris from collecting and fungus from forming on the eggs. During the next 5 to 7 days the male's only cause for existence is the protection of those eggs; he will not eat and will only tend to the eggs. This is a strenuous time for the male and it is a good idea to have a setup that doesn't have fish other than your mated pair. Even guppies will prey on the fry once they begin to hatch. Alternatively, many breeders will breed cherry shrimp in the same tank with their plecos. Both populations can mutually thrive and the shrimp are excellent at cleaning up all the excess food you will be feeding.
Once the fry begin to hatch they will stay inside the cave for a number of days. They will have a large yolk-sack attached to their belly that will be a source of nutrients during their most vulnerable time. As soon as they start coming out of the cave, it's time to start feeding them. This is the hardest part of Bristlenose Pleco breeding since you will now have 50+ mouths to feed. The babies are not strong enough to chew through foods with a thick skin. Flake foods work well at first. Another favorite is unsalted green beans out of a can. These have been sitting in water for months and are very soft and will sink right away. You can keep a can of them covered in the refrigerator for about 5 days at a time. Add a couple green beans to the tank every 8 hours or so as they've consumed them. It is crucial that you maintain the water changes at this time as chemistry in the tank will change quickly with added food and waste that will be cycling through the system.
After the first couple of weeks have passed, your job will become much more easy. At this point, the fry should be more self-sufficient and your new goal is to grow them out to about 2 inches. This takes about 3-6 months from birth. At about this size you can start distributing them throughout all your tanks and to everyone else you know who has a tank, unloading the rest to your local fish store for some credit that you can use to keep feeding your hobby! They're prolific breeders and can provide you with tons of fry if you have the tank space available. They can be known to spawn every week, unfortunately, dedicating more than a dozen tanks just for raising Bristlenose plecos is a tall order to fill.
So there you have it, a nice little breeding project that can pay itself off and be quite rewarding. A side perk is that there is nothing cuter than a horde of baby Bristlenose attacking some green beans!