Scriptaphyosemion cauveti

[retro_gk]

I have a couple of pairs that were producing eggs in a community tank with some regularity. I moved them to a 2.5 gallon tank with mops and the eggs have since dried up.

I've read Wright's spawning report on the species and my water parameters are pretty similar. Anything else I should be doing?

[stormhawk]

Privacy, lots of it. I think the move to the smaller tank may have spooked them so they kind of stopped doing their thing for the time being. Other than that, let's see what our Bloviator Emeritus has to add.

[whuntley]

Could it be a water-quality thing?

You said mops, but no mention of plants. Did the community tank have them?

How many fish are in the small tank? A couple of pairs? If more than one pair, the smaller space may encourage egg eating by another female. This is a normal and natural process for her to use the energy from the eggs of another female to assure that her genes are the ones getting propagated. In a small tank, all can be consumed.

Not enough information to do anything but guess, but my first thought was that the complete stopping of egg production could be a water issue.

IME, cauveti are not shy enough to stop breeding due to lack of privacy.

Wright

[retro_gk]

Water quality should not be an issue. I change about 20% of the water every 3 days.

The community tank had some Java moss growing on driftwood. No other plants.

I have both pairs in the same tank. This might be the problem. I'll remove one pair and see what happens

[whuntley]

Water quality should not be an issue. I change about 20% of the water every 3 days.

Sermon Mode <ON>

That is not persuasive. What is IN that change water?

If even a teeny, tiny bit of chloramine is being added, the fish will go sterile instantly. If the situation persists for a few weeks, the effect becomes permanent.

I wish I had a nickel for all the experienced guys in BAKA, on the SF peninsula, who swore they had no chlorine/chloramine, but were losing fish and encountering almost 100% sterility. Well, they weren't actually measuring, they just knew the water had none. Yeah, sure!

Oleg Kiselev was in the group, and didn't know what the real problem was. He just installed a whole-house carbon filter, anyway, and the problem vanished.

We later established that the pure Hetch-Hetchy water they thought they were getting was actually being treated by the Santa Clara Valley Water District with low levels of chloramine.

If fish stop spawning, it is the first thing I test for. My well is right across the driveway, but who knows what farmers put into the ground water.

If the dose is low-level, plants can be a big help. They use up the ammonium and the chlorine is then dissipated into the air with aeration. Neither the ammonia (from ammonium) nor the chlorine are at all good for fish.* A bare tank with mops has no way to get rid of either, so they get to poison the fish for a long time. The half life of the chloramines used in water treatment is at least 5 weeks. Adding a fresh shot every three days is a formula for making it permanently toxic.

TEST. It must be way below 1 ppm to stop hurting fertility.

Sermon Mode <OFF>

Wright
__________________
* Chloramines = Chlorine + Ammonium. A little household ammonium mixed with chlorine bleach gives chloramines. That's almost exactly how they treat water.

[retro_gk]

Hmm, interesting point, Wright. What goes in is tap water treated with ChlorAmX (this is what most of my tanks get), mixed 50-50 with RO to soften it.

This was the same water they had in the tank they were spawning in, except the water change was 20% weekly.

I must confess I never test for chloramine/chlorine. I prefer small, frequent water changes to large, infrequent ones and have never had issues with chlorine that I was aware of. One more entry in the learning book

I'll move one pair into a tank with pure RO, with some epsom salt and buffer added, to rule out the chloramine angle.

[retro_gk]

Update: I separated the pairs, got eggs out of both, put them back together (because I needed the other tank) and they're still spawning. No idea what was responsible for the earlier break in spawning. All's well that ends well.

[retro_gk]

I think Wright's theory about the females eating each others' eggs might be the explanation here. Over the past couple of weeks I've found that checking the mops every other day nets around a dozen eggs each time. If I skip a couple of days, I only get 3-4 eggs.