Corydoras dying after spawning?

[Reindas]

Hi, I have this situation. All my adult female corys (C. Aeneus) died witting a week about a month after they spawned. They still looked like they could spawn any time. So I asked me self this. What would happen if they can’t spawn but are full of eggs? Won’t the eggs be absorbed if not spawned? Will it kill them?

All the water parameters are correct, ammonia & nitrite are at zero with nitrate between 10 and 20. Ph is 7.4, GH at 4.5 and KH at 8. This is just a get it at home. I change 1/5 of the water every 3 days.

Of any of you have an idea, please let me know.

Thanks!

[bekateen]

Hi Reindas,

I'm sorry for your loss. Nobody ever likes losing fish, but especially not when they have been breeding.

As for what happens to unused eggs, there are two stories I read, both seeming reasonable but how to tell the truth in a specific instance is the challenge. (1) Unused eggs are absorbed by the female and she makes new eggs later. (2) The unused eggs create a blockage and can kill the female. We hear a lot of people blaming the deaths of plecos on being "egg bound" as in the second story, and yes it's probably the cause of deaths sometimes. But I rarely hear this story applied to corys. Also, fish die for a variety of reasons, and we have to imagine that sometimes, by coincidence, the dead fish will be a female full of eggs... but not killed by the eggs.

I know you tested the water and it was normal. But you may have had a brief spike of ammonia, which could kill the fish and disappear before being noticed. And how old were the adults?

The bottom line is that no one can say for sure why your fish died.

Regards, Eric

[Reindas]

Thanks, I really loved those little whiskers.

The fish were a little more that a year old. I got them last may and judging by the size they were abut 3 to 4 Months old. This is an enigma for me, the males are behaving like all corys do, very active and scavenging all the time also I have 4 of the fry on the same tank with the parents. I decided to divide the fry on 3 different tanks so if the fry tank crashes some will make it. Those frys are doing more than fine, they are thriving there.

One of the reasons I thought the un-spawned eggs would have something to do is because I have been told that here where I live (Puerto Rico) corys won’t spawn because is too hot. My water temperature is normally over 80, 82 to 84 most of the year. From January 8 to march 12 they spawned. It was unexpected but welcomed. We had some cold fronts and water got down below 75. Then the temperature returned to normal and stoped spawning, but kept the same eggs filled bellies.

Thanks for you comment, I really appreciate it, you gave me two posible very logical possibilities. I plan to setup a room for my tanks so I can keep them on a more stable conditions and not be only dependent on mother nature.

Thanks again.

[bekateen]

Well, from your information on age, they were not too old. Corys can live for years.

Temperature could be related to the deaths. Higher temps can drive down dissolved oxygen, and that might have harmed them. Corys can breathe air, but maybe it was just too warm.

Regards, Eric