Corydoras napoensis

By Joseph Huisman


The Napoensis Corydoras’ place of discovery was Ecuador.  In the Rio Lagarto-Cocha, a tributary of the Rio Aquarico, and in the Rio Livino, a tributary of the upper Rio Napo. The Napoensis Corydoras will attain a length of about 5 cm.  When you look for this Cory be careful; there are a couple Cory's that look like this Cory (Corydoras undulatus, Corydoras nanus).  The main way to tell the difference is it possesses a much larger dorsal fin patch.  This patch is black and is present in the upper region of the dorsal fin.  The body color is light brown with a vivid violet shimmer which is evident more so in the males then in the females.  I bought these fish at Hoffers in Milwaukee.  The price I paid was $19.95 for each fish.  They were full-grown when I bought them.  These fish were wild caught.  The trick with this Cory is to be able to raise the fry.  The fry are the smallest baby Cory's I have ever seen.  Some of you saw these babies the last time I held a meeting at my house.  When these eggs hatch the fry are not much bigger than a grain of sand.  We will talk about the fry later so let’s get into spawning information.


Spawning Information:  I use a 10-gallon tank to spawn these fish.  There is no heater in the tank.  Remember I heat my fish room.  The tank temperature is about 78F. In addition, in this tank I have a sponge filter.  When spawning these fish I have 1 female with 2 males.  To prep these fish to spawn I feed freeze dried Tubifex Worms, and Brineshrimp at least twice a day.  If you feed this for a week, you should see the female get larger as she fills with eggs.  Once she starts to show this, start to change the water at least 50% every day.  Do this for a couple of days.  Then when you think the time is right, change the water at a 75% water change with the temperature at about 68F.  This should be done just before you turn the lights off for the night.  You may have to do this for a couple of nights.  This should stimulate the spawn.  The egg size is 1.2 mm; this is a small egg for a Cory.  There will be a lot of eggs--they will lay about 100 to 300 eggs.  When you are going to remove the eggs and place them in a container, make sure that you look under the filter.  For some reason, they will lay eggs on the bottom of the sponge filter.  Most of the eggs will be placed on the glass of the tank.  Once they are done spawning, remove the eggs.  Place them in a container and place fungicide in the water.  Also, place an airstone in the container to keep the water moving.  The eggs will start to hatch in about 4 – 5 days.  When these eggs hatch, they are very small fry.  The fry will not be much larger than a grain of sand.  This is what makes these fish more difficult than most Cory's.   The first food taken will be 2 to 3 days after hatching.  The first food should be a liquid food. I use LIQUIFRY #1.  After they have been eating for a couple of days, you can try to feed baby Brineshrimp.  If you hatch your own shrimp, make sure there are no shells in the shrimp.  If there are shells, that will kill the fry.  So, be careful.  These fry are very slow growing fish.  I keep the fry in the container for at least 2 weeks.  The water in the container must be changed 50% every day.  Then I move the fry to a 5-gallon tank with a sponge filter.  They will stay there for about a month.  They will be about ¼” long when they are about 6 weeks old.  When they get to this size then I move them to a 20 gallon long tank.  This is where I keep them as they grow.  You will have to move them to more tanks as they grow.