successful fry, dying parents

Hi, I’m a new member, but I’ve been reading this forum for a long time, and it’s been very helpful. This is the first time I’ve had a question that wasn’t already answered, so I hope you all can give me some advice.

The short version is: Has anyone had their adults stop eating and waste away after the fry are hatched?

Here’s the whole story:

I’ve had four CPDs for nearly a year. Three females, one male. They’re in a heavily planted 10 gallon, which they share with 4 otocinclus. About six months ago, I started feeding a higher percentage of frozen foods versus flake/micropellets, to try to condition them for breeding. I’ve been alternating bloodworms, mysis shrimp, cyclops worms, along with a variety of freeze dried, flake, and pellet foods.

It worked! After a couple of months of finding a single fry here and there (which would disappear the next day), I set up a net breeder in the tank, and started scooping out babies and putting them in the net. I got 40 fry, and now, 4 weeks on, there are over 20 left.

Since the babies were outgrowing the net breeder, I decided to set up a separate tank two weeks ago. I hedged my bets by putting 10 fry back in with the parents, and put the rest in a barebottom Q tank. Both sets of fry are doing well, but the ones in the parents’ tank seem to be growing faster. There are at least six still alive in there.

So here’s the problem: Since the first fry in this batch appeared, the parents have stopped coming out to eat. They’re always shy, but they used to patrol the tank each morning when the lights come on, and come out to feed each evening (until the fry, I was feeding once a day).

I thought that since I was feeding so much fry food, maybe enough was getting into their hiding place (behind the driftwood, out of sight), that they just didn’t need to come out to eat.

One week ago, I came home to a dead oto and a dying female CPD. I took her out and quarantined, but she died overnight. She had been listless, swimming at the top, and slightly tilted.

ammonia 0, nitrite 0, nitrates ~20. I still assumed it was a water quality thing, since I’d been overfeeding to get them in breeding condition, and over feeding to keep the fry fed. The tank was admittedly, a mess – algae, snails, and crud everywhere. I did a 20% water change that night, and another 20% the next day. I used a different test kit, but ammonia and nitrite still read at 0.

I did a large water change on Sunday (>50%). Tuesday, my only male was dead.

Yesterday (wednesday), the remaining two females were swimming about and they didn’t look good. They’re very skinny, very pale, and kind of listless. Since they were out, I tried to entice them to eat brine shrimp and micropellets soaked in garlic. I don’t think they went for it.

Meanwhile, the fry are doing great! If it were a water quality problem or a disease, wouldn’t they be the first to die? It really seems like they’re starving themselves to death.

I think these guys were wild caught. Their colors were stunning, and I’m crushed that I’m losing them. I didn’t treat for parasites when I bought them, so now I’m doing a couple of rounds of levamisole – one is completed, two more to go.

Background on me – my husband and I have been keeping fish for three years, and have several planted tanks (mostly devoted to loaches and other SE Asian fish). This is my first attempt at breeding.

and for wading through all that text, here’s a picture. The net is no longer there, since the babies outgrew it.

Thanks for any help!