Some time ago I received a breeding group of seven Corydoras similis from a fellow hobbyist. C. similis can be confused with C. maculatus. The spot at the base of the tail is more distinct in C. maculatus, less so for C. similis.
The group was kept in a community tank with other Corys and other fish. There they stayed for a year. Finally, I decided to provide them with tank of their own. Live black worms supplemented the usual flake food.
It must have been the timing, because they spawned one week later after the move. As with most spawnings, I did not observe the act. During this first spawning, only about 30 eggs were removed to a separate tank.
A couple of weeks later, the parents proceeded to spawn after I had moved the group back to the community tank. This time, I was able to witness part of the process. Only one pair was observed actively spawning. Others went about their own business. An additional 40 eggs were removed. Unfortunately, I was on a business cycle of going out of town. Upon my return two weeks later, the young had hatched out. The percentage of fertile eggs is only around 50 percent.
The weeks then months go by. The fry grow very slowly. At two months the young are about one half inch.
In summary, C. similis is easy to breed, if given a chance. For whatever reason, my group seems to have a low fertility rate.
This article first appeared in PVAS’s Delta Tale, Vol 32, # 2