Cory Hatching - Fact IS Stranger Than Fiction

[Coryologist]

Greetings All,

I thought I would relate a very interesting occurrence that just took place. I have close to 200 - 10 G. tanks of fancy guppies. I generally keep 6 to 10 Corys per tank, depending on their size. For years I've watched them lay eggs and then watched the guppies and the Corys themselves EAT the eggs. I always figured I was busy enough with the guppies to worry about it.

A couple of months ago I had to break down a tank that was in need of a good cleaning. After removing the fish and the plastic plants I use for fry cover, lo and behold - a couple of hundred eggs were on the back glass. I decided what the heck, I'll just put in a couple of drops of Meth Blue and see what happens. About 3 days later I have a couple of hundred albino fry scurrying around the bottom of the tank. Very cool! About 150 of them are now about 2 months old and doing great.

So, I'm breaking down another tank last week, get it completely emptied and discover about 150 eggs on the rear glass that I did not spot until all the water had been removed from the tank. I quickly spun the tank around so I could see the eggs and placed the original water that was luckily in a 7 gallon bucket on the floor bank into the tank. I added a little fresh water to cover the eggs and again, a couple of drops of MB. A few days go by and nothing happens. It appears that these eggs are smaller than the albino eggs that had hatched and they were pinker - or actually more of a "rust" color than the others. A couple of more days go by and still nothing. So I assumed that although they were not attacked by fungus, they probably were not viable. Since I really needed the tank I decided to forget them and put some guppy fry in it. Upon going back into the main fish room I spot this huge spread of eggs in a tank and already the Corys and the guppies are going after them. I decided to try to save them and move them to the other tank with the bad eggs. I have never tried to move Cory eggs from one tank to another before. I took a tiny brine shrimp net and gently scraped them off the glass and actually got most of them in a couple of passes. I dash to the small room and while I'm putting them in the tank I realize that the old eggs look different somehow. At least half of them, anyway. Unbelievably - in the 5 to 10 minutes I was in the other room - the old eggs started hatching and I have a few dozen grey fry whirlygigging all over the bare bottom of the tank. After dropping in the new eggs I pulled up a chair, put on a pair of high-powered reading glasses and actually watched the fry bust out of their egg casings. I've been raising tropicals for over 40 years and it was one of the coolest things I have ever witnessed. Within an hour or so 90% of the eggs hatched and I only saw 1 dead fry.

So now I'm a dedicated, albeit, neophyte Cory breeding junkie. After buying literally many hundreds of Corys at anywhere from $1 to $3 each - those days are now over. I probably have 15 different strains of Corys, with oftentimes 3 or 4 different strains in a tank. This raises some questions that I would greatly appreciate responses to.

1. Should I make it a point to only house Corys of the same strain in each tank - being careful not to mix and match? I did see some "heated" debate on this Forum about cross species breeding with the general jist being that this is a no-no.

2. Under normal circumstances, won't Mother Nature take care of that problem?

3. More than any other - I LOVE my Corydoras Sterbai and my albino Corydoras Sterbai. Are they any harder to breed than the others?

I thank you all in advance for any assistance you might offer. - Frank/Guppyman

[Rusty]

1. Should I make it a point to only house Corys of the same strain in each tank - being careful not to mix and match? I did see some "heated" debate on this Forum about cross species breeding with the general jist being that this is a no-no.

2. Under normal circumstances, won't Mother Nature take care of that problem?

Cross-strain breeding is definitely possible, for example between C. aeneus "Green stripe" and the normal aeneus (this would probably result in an unattractive mutt). For this reason I would keep strains of the same species apart. However, cross species breeding (hybridization, the bad practice) is rare with cories, unless two similar but geographically isolated species are kept together. This is because the fish lack the instincts that tell them that their mate is of a different species although it looks the same, because the two would never encounter each other in the wild. It shouldn't be a problem.

3. More than any other - I LOVE my Corydoras Sterbai and my albino Corydoras Sterbai. Are they any harder to breed than the others?

Never bred them myself, but they supposedly aren't much harder than usual.

Rusty

[madattiver]

congrats on your new found interest in cory's.. i myself have transfered from my swordtails to more interest in cory's anbd have already spawned 2 of my 16 species and am working on my c. sterbai.. i will let you know if i get these guys going and will pass the info onto you.

[Viking Bear]

First of all c. aenus and c. aenus 'albino' are not a different species. They are a cultivar of the species. There are three different types of albinos that I know. They are paleatus, aenus, and sterbai. There may be more. They are easy to recognize from each by body shape and sterbai have an orange lower belly. Last year, I put one normal aenus male with a breeding group of albino. The fry are not a blended color but exactly the same as the father. They normal fry grew much faster than the albino. My guess is normal can see better than albino. Many albino species have poor eye sight.

They are a bunch of different color forms i.e. black, orange stripe. These might be other species. Albinos are not often found in nature. They are too easy to see some are the first ate by preditor.

If you do not have room for all your different species of cory. I would suggest that you only keep species that obviously different that way if hybrid appear you will know.

Keep them swimmin",

Scott