Curled opercula?

[flaringshutter]

Anyone have any experiece with curled gill plates? I have quite a few fry in my latest batch with curled/shortened opercula. It's too bad, since the fry are otherwise excellent in terms of conformation and coloration. Is this condition genetic or a result of something I did/did not do?

[Cincy Ranchu]

Anyone have any experiece with curled gill plates? I have quite a few fry in my latest batch with curled/shortened opercula. It's too bad, since the fry are otherwise excellent in terms of conformation and coloration. Is this condition genetic or a result of something I did/did not do?

This shows up from time to time in many lines of fish. It is most common in Ryukin and Tosakin, but I have seen it is calico Ranchu, Veiltails and Bristols.
Many people argue it is genetic while others try to tie it to poor water conditions and overcrowding when raising spawns. The best thing to do is not breed these these fish and look carefully at the parents of the babies.

[mikroll]

Anyone have any experiece with curled gill plates? I have quite a few fry in my latest batch with curled/shortened opercula. It's too bad, since the fry are otherwise excellent in terms of conformation and coloration. Is this condition genetic or a result of something I did/did not do?
hi flaringshutter, I have had that happen too. but not present in a repeat of spawn so I tend to think that even if it is genetic it will not always be present in each spawn.

[flaringshutter]

Well the fry are a batch of midnights... and I haven't been as diligent with water changes as I would like to be (busy with the day job) but the problem is in nearly all of the dozen or so fry I have. So perhaps it was a genetic flaw triggered by water conditions?

[Virginia ranchu]

I agree with everything Gary said, and I have also seen this most often in Ryukins. My guess is that this is a combination of genetic predisposition as well as water quality and growth rate, or protein content of food (which of course affects water quality and growth rate). Ryukins have pointy heads on big round bodies. If the operculum grows faster than the length of the head, the new tissue might be forced to curl outward.

I often save some of my "culls" (the American culling method according to John Parker) by moving them to another tank or pond:). These fry get no special attention, and much less food, but often benefit from better water quality. Though smaller, these fish do not exhibit curled opercula or fins. My recommendation is to split your fry among different size tanks with different densities, an outdoor pond or tub would also be a good variation. See if there is any difference in the frequency of this problem depending on the conditions.

I also think that non-metallic fish have "softer" fins and operculums, which might be more sensitive to water conditions. I have also seem more mis-shaped mouths in calico fish.

[Cincy Ranchu]

Great comment about Calico and matt fish having softer operculum, in the abscenece of guanine they bend easier, I like this answer! Where is Parker when we need him!

[Sabine]

From what I have read, goldfish with curled operculae are quite popular in China. The rest of the world just doesn't seem to share this preference. The website of the Chinese Godlfish Museum shows lots of fish with curled operculae:
http://www.kepu.net.cn/english/goldfish/index.html
So I would think it's a lot of genetics.

[Ichthius]

In zebrafish there are strains that have this as an obvious genetic effect.

Then there are cases where I believe it to be environmental. There are many plastic leachates that can effect development. The main things to watch for are plastisizers used to make flexible vinyl, plastics and rubbers.

We found one type of plastic used by a manufacture of aquarium related products that in low does caused all the caudal peduncles to be slightly off center. When fish were raised over large amounts of these plastics in a static situation they grew up with no tails. The dorsal and caudal fins fused and pinched off the tail.

If the trait has not been seen in the line recently I would suspect an environmental toxin.

[bekko]

I love this topic because you always hear so many different answers. But, I really hate it when a nice batch is ruined by a high incidence of curled opercula.

A nutritionist/physiologist friend swears it is caused by a Vitamin C deficiency. However, you also see curled opercula in green water systems which should be replete with Vitamin C.

You see curled opercula in just about every species of cultivated fish, freshwater and marine. You see it in progeny of wild-caught parents. But, you never see it in wild fish. This makes me think it is largely an environmental issue.

-steve

[flaringshutter]

Thanks for all the answers everyone!

I am feeding a mixture of flake, Mazuri gel, OmegaOne pellet, and frozen brine shrimp. So I can't imagine it's a vitamin deficiency.

However, their tank is in a room with the cat litterbox. That's the only thing I can think of that might be putting unusual chemicals in the air. I use wheat-based litter (no toxic chemicals), and scoop regularly, but perhaps the ammonia in the air from the cat waste?

I have moved my few fry without curled opercula into a breeding box in the big tank. A few are doing much better, a few seem to be doing worse. For now, I'm not culling the good fry with the curls. We'll see how they develop.