Spawning Corys:

I was told that to get well conditioned (fed) adult Corys to spawn one needed to dump somewhat cooler water in the tank to simulate a tropical rainfall. Perhaps their favorite foods are blackworms, white worms or chopped earthworms. I'd go the the former after thoroughly rinsing them.

A female and two male paleatus were set up in their own ten gallon tank with a blackworm bowl and sponge filter. It was a December day (winter break) when almost half the water was taken out of their tank. A bucket with water of the same chemistry had been sitting on the floor for a week. It was at least 6 degrees F colder. It was, somewhat reluctantly, poured in.

Unfortunately I had to duck out on an errand to a store. When I returned the Corys had already hung a couple 100 eggs on the tankside!

That storm thing must have some validity. Both a number of Corys and cichlids here would spawn after winter snowstorms and summer thunderstorms. They must have felt the barometic changes that accompany such events and assumed that it was procreation time. Special tanks, community tanks, it made no difference.

It is amazing to me that the farms in Florida sometimes still inject them with hormones so they can get 100s of Corys spawning at once. Just imagine how hard it would be to hold a 1000 of those little guys and inject each one - all in a day's work. I wonder how many times I would get stabbed with a fin or that needle!

As for images:

I've met David Ramsey through killie circles. I always look forward to his posts and photos on Killietalk.

Looking at this site, you can tell that he is fond of Corys too. Check for the eggs those albinos have hung on the tank sides (and probably upon the plants too.) With many egg layers, cloudy eggs mean that they are infertile. There are many exceptions to that rule. Corys are one of them.

I removed my Corys from the ten gallon tanks when they spawned and let the fry hatch out there (after a big water change to remove spawning by-products) and shaded the tank. In community tanks, some aquarists will take a razor blade and gently separate the egg from the tank side and turkey-baster it out. The eggs are placed in a pickle jar with an airstone and often a little methylene blue.

It is amazing to me that the farms in Florida sometimes still inject them with hormones so they can get 100s of Corys spawning at once. Just imagine how hard it would be to hold a 1000 of those little guys and inject each one - akk in a day's work. I wonder how many times I would get stabbed with a fin or that needle!

http://www.djramsey.com/tropfish/albpal1.jpg

In the upper right photo of this page, you can see the smaller male courting the female. The following shots are obviously also of spawning Corys. Unless it is just because they are out of focus, it looks like they have both the bronze and C. similis spawning. I hope it is just one species. The URL suggests similis.

http://www.aquajapan.com/stock/catfish/breed/corydoras/similis/similis00.html

I've mentioned on GL before that a lot of female egg layers can be distinguished from males by their greater girth. With a number of species of fish the males have more vivid color or detailed markings. They may have longer fins too and the author, in the following article, suggests that those characteristics also apply to at least some Corys.Her comments about bristles applies more to male bristlenose catfish (Ancistris and the like) where the males are much more in need of a shave than the females..

http://www.calgaryaquariumsociety.com/Articles/Eenie_Meenie_Minie_Moe.html

All of these were hustled from a quick Google image search. Assuming that you do a better job of typing [ spawning Corydoras ] than I first did, you should find a lot more images and info that way.

You will get even more info if your search the web.