Reproduction
Though not exactly common or easy, quite a few aquarists have succeeded in getting their otos to spawn. This is often the result of serendipity, rather than any conscious effort on the part of the aquarist. In large planted aquaria, the first indication that the stork has visited is simply the fact that there are more Otos now than there were a month ago! Eggs are laid in small clutches, usually in remote corners of the tank that are easily overlooked. Fortunately, the tank's other inhabitants also easily miss them; so many eggs often survive to release fry. Only after two or three weeks do the tiny fry begin to resemble the adult form, and it is typically at this stage that they become apparent to the aquarist for the first time.
Remember the small conditioning aquarium we mentioned earlier? This is also the perfect breeding tank. Given that you can actually summon the effort to remove them from the main tank, a heavily set female and at least a trio of males should be added to this environment and treated to regular water changes. Eggs are easier to spot in this scenario, and it is best to return the parents to the main tank or another similar holding tank in order for the fry to hatch unmolested. Although some breeders maintain that well-fed Otocinclus do not eat their own eggs or tiny fry, at least as many report much greater brood counts if the parents are removed.
