Medaka rice fish colony not breeding

[Minifish]

Hi,

I am looking for advice on my rice fish colony . I have a group of 7 (3 females) living in an a patio pond single species pond (maybe odd small snail ) it’s about 16 gallons but long rather than deep. They are active and happy .  They have been here 6 week water parameters okay and temperatures are hot enough in the day for breeding but drops a bit at night. In the first few week some maybe eggs covered a bunch of Java moss so I placed than in a jar so didn’t eat . A month later nothing has hatched . 

The 2 of the 3 females have massive belly’s and the males are chasing (they do seem to exhibit breeding behaviour and males get very bright ) . They are feed small amounts 3 times a day once with a high protein powder, love brine shrimp, then dried daphnia or bloodworms. The pond has a lot of plants in mixture of rooted oxygenators, floating plants etc. The bottom has some gravel at the back with the front bare. I also have lots of structure using pots and rocks . After removing the Java moss I put two killi spawning floats in . After two weeks of no eggs 9 on them they do swim through them though. I tried a filter material looks like fake Java moss  ( used it previously for a different breeding project)  still no eggs. 

I was planning to breed them as they go well with a different fish i breed (hobby) so people can by them to put with my other types . 
Here’s my dilemma I supposed to have 12 more arriving in a few week (different colour separate pond). But do I change the order: 

- Is it because my groups small ? Should I order more of the same colour 

- should I remove the adults into the second pond for a few week and see if any fry hatch ? Holding off on the other 12 for a bit .

- is there anything I am doing incorrect or can do to improve the rates of breeding 

I went with rice fish because they were meant to be easy to breed maybe should have got WCM …. But I do like them as a rice fish ! 

Many thanks 

[TOtrees]

I had two ~40 gallon tubs in my yard last summer with daisy's and medakas. Both took longer than I would have expected to get babies. But they worked out in the long run, without any mops. I suspect your adults are eating the eggs and any fry that hatch. If this is the case, it will likely continue until there is really good cover for the babies, and/or the adults are getting enough food that they aren't interested. I had water lettuce (regular not dwarf) in one pond, and water hyacinth in the other. Both had a fairly large chunk of java moss, attached to a cork with a rubber band to it floated. 

PS I'm in Ontario, not far from Toronto. So fairly short season as far as outdoor fish goes. 

Edited May 31, 2023 by TOtrees

[nabokovfan87]

I would guess that there is a few things going on.  How shaded or seculuded is the pond?  Is it easy for the fish to feel safe and secure without constant checking for eggs and fry? 

I imagine that if a person walks up, direct sunlight to the back (or a light or some kind behind them) it would spook the fish pretty easily.  Floating plants, cover, even having something in the midwater for the fish to hide or swim through.

I found this article, it might shed some light on something you're seeing in the pond or speak to feeding a certain food at a certain cadence.
https://www.tfhmagazine.com/articles/freshwater/the-ricefish-an-odd-and-interesting-group-full-article

I would get another color, have the confidence that you'll eventually get some fry and just enjoy the process of trying to get them going.

On 5/31/2023 at 5:17 AM, Minifish said:

The pond has a lot of plants in mixture of rooted oxygenators, floating plants etc. The bottom has some gravel at the back with the front bare. I also have lots of structure using pots and rocks .

Based on this I would think everything is good in your setup.  Give it time.

[Minifish]

On 5/31/2023 at 7:20 PM, TOtrees said:

I had two ~40 gallon tubs in my yard last summer with daisy's and medakas. Both took longer than I would have expected to get babies. But they worked out in the long run, without any mops. I suspect your adults are eating the eggs and any fry that hatch. If this is the case, it will likely continue until there is really good cover for the babies, and/or the adults are getting enough food that they aren't interested. I had water lettuce (regular not dwarf) in one pond, and water hyacinth in the other. Both had a fairly large chunk of java moss, attached to a cork with a rubber band to it floated. 

PS I'm in Ontario, not far from Toronto. So fairly short season as far as outdoor fish goes. 

Thanks they have lots of water spangles that float covering 1/5 of the surface, a few bits of horwort (think that’s what it’s called ) than some larger potted plants that give cover . I saw a female with loads of eggs yesterday afternoon , although an hour later she had non and could only find two eggs on the spawning mops  (fingers crossed they hatch ) . Maybe i have been looking at the wrong time as i thought they laid eggs in the morning ? Maybe more plants is need 

thanks 

[Minifish]

On 6/1/2023 at 5:19 AM, nabokovfan87 said:

I would guess that there is a few things going on.  How shaded or seculuded is the pond?  Is it easy for the fish to feel safe and secure without constant checking for eggs and fry? 

I imagine that if a person walks up, direct sunlight to the back (or a light or some kind behind them) it would spook the fish pretty easily.  Floating plants, cover, even having something in the midwater for the fish to hide or swim through.

I found this article, it might shed some light on something you're seeing in the pond or speak to feeding a certain food at a certain cadence.
https://www.tfhmagazine.com/articles/freshwater/the-ricefish-an-odd-and-interesting-group-full-article

I would get another color, have the confidence that you'll eventually get some fry and just enjoy the process of trying to get them going.

Based on this I would think everything is good in your setup.  Give it time.

I only check for eggs in a morning. I tend to feed at the opposite end of the tub so I can check whilst they are distracted . They are in direct sunlight which they seem to really like but there’s a lot of plant cover and a few pots to hid in . I when in the afternoon (1pm) yesterday (normally early morning 7am , 4pm  and 8pm) . Went in saw the female carrying a massive bunch of eggs . Went back an hour later they had gone I managed to get two off a spawning mop but she defo had more . I think that’s I have been checking too early or late and they are eating the eggs . Which is annoying as they eat loads . Maybe will try putting live daphnia in as it will live a few days then the snack bar is open all the time . Thank I think I will order some more of the other colour as they are breeding I just need to stop them being eaten , I think 

[nabokovfan87]

Does the pond need any nutrients to encourage plant growth?

On 6/1/2023 at 2:23 AM, Minifish said:

Maybe will try putting live daphnia in as it will live a few days then the snack bar is open all the time

Sounds like a good plan!

[TheSwissAquarist]

This might help @Minifish: https://www.aquariumcoop.com/blogs/aquarium/spawning-mop

Get them to spawn on there, then take out the sponge mop and raise the fry separately. 

[Minifish]

Hi guys,

thanks for the advice , I did some moving around of fish and decided to put the group in a tank with a heater . Mainly was thinking I could see females carrying eggs . They have been spawning well increasing in numbers by the day . Which is great . But I have seen they lay the eggs late afternoon! 

[TOtrees]

FYI my experience has been that egg predation is less of an issue than fry predation. Meaning, it's not super critical to get eggs out as soon as they're laid, but rather find ways to protect fry when they hatch. That might be removing the plants or mops that the eggs are being laid in to a different tank, or ensuring there's enough cover in the tank if not pulling the plants/mops. Also, have you seen ANY fry? They are super small and I wonder if you might be missing them? I've found that the new fry tend to find small gaps in the surface veg, and don't really share those gaps unless there are a lot of fry. Eg 1 fry in this gap, 1 in that gap and so on. Ideal gaps are maybe golf ball size? Big enough to be a gap, small enough that the fry can get to cover fast.