Best breeding stratagey

Well, the fish don’t evolve so fast that data which are few years old are not relevant anymore Anyway, at the moment I have 18 tanks (6 aquariums, 12 plastic containers) with various combinations of F/M ratio, substrate (fine sand, fine gravel, somewhat coarse gravel) and spawning media (moss and mops), to test what works good and what works less effective. Will let you guys know

First of all, do some more runs of the same setup. There are many possibilities to get the outcome “no fry” – 1. The females are not producing eggs 2. The males are not good, so the eggs are not fertilized 3. The eggs were eaten by the parents or by other fish. 4. The fry was eaten by adult fish 5. The eggs were fertilized and developing, but died at some point because of, say, lack of oxygen in the spawning mop… etc etc etc. Only after doing several runs of the same setup you will be able to tell something about the real number of fries you can get. Running just once, and then changing something, makes impossible to tell if the outcome is “true”, or if it was just a result of pure chance. This is why I set up so many tanks, and I will be testing at least two times, if not more. Only such approach allows to separate the reality from the chance (especially in case of these little bastards )

Dennis, what do you do with the fry after removing the parents? I mean, do you keep the fry in the tank, feeding them and waiting till they grow to ready-to-sell size, or you remove the fry to another tank?

Keeping fry in the breeder has one advantage – one doesn’t disturb the fry, and two disadvantages – the breeding tank is blocked as long as the fry is there (=you can’t breed adults again as long as the fry is there), and the volume is a little bit small for raising the fry to the ready-to-sell size (the bigger the tank the faster the fish grow, and the more stable are the conditions). The trade-off would be to wait for the fry grows a bit (say, 3-4 weeks), and then transfer them to a larger “grower” tank (still, the breeder is blocked for 4-6 weeks [1-2 weeks to complete hatching + 3-4 weeks for growing]).

Removing the fry has one advantage – removing the fry frees the breeder tank, so one can breed adults again there, and three disadvantages – removing tiny fry will take a lot of time if using plastic cup or “glass fry catcher”, netting them (which is definitely faster) might hurt them, and putting them to a larger tank with different conditions might also be stressful for them. But – one is able to collect dozens or even hudreds of fry in one large tank, which makes caring for them a lot easier.

I was also thinking about transfering the tiny fry to smaller tanks, like 1 US gallon, cuz it’s easy to fill such tank with the water from the breeder tank, and it’s easier to feed the fry during first days (high concentration of food in the water, the fry doesn’t need to look for the food – important for microworms, for example). After a week or two, when the fry reaches artemia-ready size, I’d transfer them to a larger “grower”. At the moment I’m not sure which will work best, so I’ll test everything

Another great way is to use egg traps – parents stay in one and the same tank, happy and undisturbed, and what is transferred is the eggs, which are not so sensitive as the tiny fry. Disadvantage – one is never certain if 100% of eggs were laid in the trap. This is why I want to test what the fry number will be when removing the parents from the breeder (100% of eggs are laid in the breeder, that is sure like taxes ), and compare it to the number of fry obtained when using the egg trap. Work in progress (I’m aiming for getting about a thousand of fish per month, this is why the differences begin to be important).

Dennis, did you notice any changes in the eggs/fry number as the parents become older? And what’s your average fry number in the setup 5,5 US gallon with 1m+3f?

Best,

Piotr K.

@shift wrote:

Well the parrents have been removed from the mesh bottom/mop experiment for a little over a week. saturday i spotted 3 fry, today i’m up to about 5… so it didnt work nearly as well as i hoped.

Hey, do you have a picture of your setup? Then we’ll see what we are talking about

@shift wrote:

I build an egg trap version of the mop and placed it into the shrimp tank with 2f/2m in it.. to see what happens

I’d do it like this – setup a 5.5 gal tank with coarse gravel and lots of moss, put your fish there, wait for a week, remove them, wait with patience another week-2 weeks to check if there are any fries. Repeat it at least twice, to see what the fish are able to produce in optimal conditions (and I’m pretty sure at my level of CPDs-breeding knowledge that a coarse gravel tank with moss is the optimal setup – I was even more convinced by what Dennis wrote recently ). In my opinion there is no need to use mesh bottom when using a mop – simply because the eggs stay in the mop, they don’t fall down (at least in my mops). Another thing which you could do (and which I did many times) is to remove the mop itself after a week, shake it into any small container with water, and see if there were any eggs inside.

@shift wrote:

Piotr K. – 1000/month! damn you must have one big grow out tank!

Mate, I have about 50 tanks at home Six growers altogether, about 100 liters each. I do not grow all the fries in one large tank!

Hey, the first layout is amazing! Is it Fluval Edge? Are the plants growing so nice under such weak light? Wow!

As for the setup for the first attempt – it must have been a struggle to catch the adults in such densely planted aquarium… :mrgreen:

As for the setup for the second attempt: 1. The mesh size (the “eyes” of the mesh) is too small IMHO, it should be about 3-4 mm (not bigger, because adults, when scared, can easily get stuck in it) 2. I’m not surprised that the number of fry was smaller. You know why? Because the mop is a hanging one, so the spawning looked like this – the fish spawned in the mop, the egg fell down OUTSIDE the mop, and landed on the mesh; it didn’t go through the mesh, because the “eyes” are too small, so adults ate almost all the eggs (that’s what I think). Generally, CPDs breed in plants/mops, but the eggs are not adhesive and fall down – therefore the best mop is a mop which is laying on the bottom, not a hanging one.

The picture of the mop, bare bottom and a rock on the left side – the same situation, mop is hanging, and it doesn’t even touch the bottom. So, every egg which is laid within the mop will fall down, right onto the glass, where it will be easily found and eaten by the adults. Mops must lay on the bottom, or at least touch the bottom when hanging.

Egg trap – think like a fish: if given a choice between spawning within all the plants, and spawning in an artificial “grass” made of wool, what would you choose? Egg traps don’t make any sense if you have other plants in the tank, cuz CPDs will breed in the plants, not over the trap. Second problem – the “eyes” of the mesh are IMHO too small, so no egg will fall through them. Eggs of CPDs are pretty big for such a small fish, about the size of the eye of CPD.

I’ll post some pics tomorrow, as the lights over my tanks are off now (it’s 10:15PM here in Poland )

Dennis, thanks for the details, your schedule seems to be very good for getting healthy fish! One question, because I’m not sure if I understood correctly:

@BallAquatics wrote:

First time breeders usually produce 15 to 25 fry per set-up and top out at 75 to 100 per set-up. If I had to pick an average I say 50 to 65 fry. That’s how I come to use 20 gallon grow-out tanks.

These numbers are for one breeder tank per one week, right?

Aha, and one more question – I see you have D. erythromicron as your avatar. Do you breed them, too? If yes, what’s the growing speed of the fry, comparing to CPDs? My experience is they grow two times slower than CPDs.

@Piotr K. wrote:

These numbers are for one breeder tank per one week, right?

Hi Piotr, yes that’s for one breeder tank per one week set-up.

@Piotr K. wrote:

Aha, and one more question – I see you have D. erythromicron as your avatar. Do you breed them, too? If yes, what’s the growing speed of the fry, comparing to CPDs? My experience is they grow two times slower than CPDs.

Yes, my avatar is Danio erythromicron. I do have a breeding group of these, but I don’t raise them in the quantities that I raise CPD. I always think that it seems as though both of these fish grow slowly, but I think it’s just a matter of perception. They are small as adults so they don’t appear to grow in size like fry from larger fish do. If you think about it thought, they are sexually mature at 12 weeks old so really they are growing very fast… they just never get very big!

You are correct though, I think the D. erythromicron grow slower than CPD’s.

Dennis