Breeding Corydoras davidsandsi This species from the Aeneus Group is found in the middle stretches of the Rio Negro in Brazil and is a look-alike. It has the same colouration as C. metae from the river of the same name in Colombia, but davidsandsi has a longer snout and the black stripe carries on into the bottom lobe of the caudal fin, while C. metae stops short at the caudal peduncle. The C. melini connection has melini having the same black body stripe ending on the bottom lobe of the caudal fin, but the stripe separates just behind the dorsal fin and continues as two lines over the back of the body. The colouration is also different, with melini being a dirty white with black specks to the edges of the body scutes, while davidsandsi has a tan colouration with no specks. If you can make all that out I will explain how I spawned this species (C.davidsandsi that is ).
This picture shows the black stripe running along the ridge
of the back. This went on for three months until I decided to give them one more try. I placed a powerhead in the tank for extra aeration and then carried out a 75% water change with part rainwater and flooded the tank with white worm. I then locked the fish house and hoped for the best. Yes you know what I'm going to say - the next morning I found a total of 14 eggs laid on the Java moss and Java fern. I removed the eggs and put them into a small tank with water from the breeding tank . I used light aeration, but three days later only four hatched as eight had fungused and two were not fertilized. I had to go away for two days and I lost the fry due to not being able to change the water. I needn't have worried though, for a week later they spawned for me again. They laid only five eggs this time which I put into my small tank again, but with no aeration this time. I also added meth. blue to the water.
They hatched in three days, and after two days I started feeding microworm as first food along with egglayer fry food. I did 50% water changes every day. The next spawning was a week later, this time thirty eggs were laid. I watched the spawning sequence this time which occurred at 9 a.m. One male chased the larger female as they took up the customary 'T" position, with the male grabbing the female's barbels with his pectoral fins and pushing her very hard. She then broke away from him after about eight seconds, then she sat on her side for a further few seconds, then expelled one egg into her ventral fins. She would travel about the tank with the male chasing her for what seemed ages, before she would lay the egg usually in the Java moss but sometimes on the glass. I noticed that the other male was trying to get into the act, but the dominant male was chasing him away, so he would go and try to spawn with the other female, but she was never interested. I keep the fry in the small tank for two weeks, then I move them to a seven gallon growing-on tank with a corner filter, doing water changes every other day. This is when I start feeding brine shrimp as well as microworm and crushed flake.
This (out of focus!) picture is of an 11 day old fry. For the record, the pH was 6.8 with the temp. being 80ºF during the day and dropping to 76ºF during the night in my fish house. The water is very soft in this part of Scotland at G.H.l. A lesson I have always learned from breeding Corydoras is to have patience and plenty of it. |
C. davidsandsi egg
C. davidsandsi fry