Corydoras paleatus

(The original of this article was first published in the Sacramento Aquarium Society Newsletter , The Tropical News April 1994, Volume 43 , Number 4.)

These fish originally come from La Plata, Southeast Brazil. They were discovered by Jenyns in 1969. Their synonyms are: Callichthys paleatus, Corydoras marmoratus. They grow to 2 ¾" (7cm.). There is also a seudo-albino form frequently found in the trade today. They prefer water values of 6.0-7.0 pH and 6º dGH. The best water temperature is around 75-79º F (24-26º C).

The first time I spawned this catfish was in the summer of 1987. I bought a 10 gallon tank in the beginning of the year from a neighbor in Corning, Ca. who was tired of keeping fish. The tank contained a pair of Angelfish, one Corydoras paleatus, several Cardinal Tetras and a few other species.

For those people who are used to spawning cichlids because of their parental care, you will not find the same care in the Corydoras. After spawning the corys only interest in the eggs would be to devour them or the fry after hatching. Either the eggs or the parents have to be removed in order to save any fry.

Corydoras are really easy to sex. When the females are mature (ready to spawn - usually at 3 months) they will appear more rotund compared to the male who is definitely slimmer. Looking at the fish from the top is the easiest way of sexing them. From above one can see that the female appears to be wider at the pectoral fins and the male is widest BEHIND the pectorals. The female will still be the widest of the two. Corydoras can also be sexed from looking at their vents. If the females are mature, she will have an oval shaped vent, the male will have a lengthwise slit. (This method is best observed after the female has spawned at least once.)

After having the tank set up for about a month I noticed there were small ‘bubbles’ on the tank glass. I had no idea what could have made them. I soon realized they were eggs and not bubbles. The only fish I was breeding at that time were Guppies, Swordtails, Mollies, Herotilapia multispinosa (Rainbow Cichlids), and Hemichromis bimaculatus (the Jewel Cichlid).

Paleatus corydoras are known in the retail business as Pepper Cats. I have been in shops in the past and noticed new names being added to these fish. All in all they are still Corydoras paleatus.

The best way I have found of spawning these corys is to have at least two males for every female. I usually keep one group per 10 gallon tank. It makes it a lot easier for keeping track of "her" productivity.

I watch for two things when I use a female for production:

a) Quantity of eggs fertilized. Not many fertilized eggs could mean the female isn't spawning with the males or the males aren't fertile. I usually switch males after two infertile spawnings. If the female is still producing 'bad'' eggs I quit using her.

b) Are they eating their eggs? If they eat their eggs and are doing quite well production-wise, I keep the group but put a note on their production sheet to remove the eggs the same day as they spawn. If no eggs are being eaten I leave the eggs until the next day.

The two groups I have spawning now spawn every three days and in the same place. I wait until the day after spawning to collect their eggs. If I miss collecting the eggs the two groups will lay their ‘new’ eggs next to the older egg clutch! The eggs hatch in five days at 78ºF. The Corydoras paleatus eggs measure 1.86 mm in diameter. The fry are able to eat newly hatched brine shrimp after absorbing their yolk sacs, which takes another one to two days.

I place my collected eggs (as with all my cory/catfish breeder eggs) into nets in "hatching" tanks. These hatching tanks have a heater to maintain a constant 80ºF. temperature and a sponge filter. If I use the normal green nets that we have around the house or in the fish room, the fry after hatching, go through the holes in the net and fall to the floor of the tank, where I leave them to absorb their yolk sacs before releasing them into a rearing tank that is also set at 80ºF. and contains a sponge filter.

If fed several times a day and the temperature is left at 80ºF. the fry should be 1 ¼" by the third month. Something I do, that a lot of people I have told think is a lot of work and that I must be out of my mind to do, is to check my eggs after collecting them by putting them into a clear glass bowl and placing it over a light. I remove any dead eggs. (These can be identified by their white coloration and not a clear yellow like that of fertile eggs.) To some it would seem like a lot of work but I cut down considerably on good egg loss due to close contact with fungusing eggs. It does keep me busy but I believe it is well worth the effort. If you have read my other articles you will find I do not use any chemicals for hatching my eggs.

In 1988 I started using Methylene Blue and found I had a lot of deformities with my new fry. I have a lot of success hatching my eggs without the chemicals and I am happy with the results.

The Corydoras are a great fish to spawn. You will notice your spawning female getting larger with eggs with each successive spawn. This also means that each successive spawn produces more eggs/fry.

Whichever way you choose to spawn, hatch and raise these fish, you will find that they are quite hardy.

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