- This topic has 54 replies, 8 voices, and was last updated 9 years, 11 months ago by
.
-
Posts
-
Fine!
That they become white after eating, I still didn’t notice … Perhaps mine do also….I light the filter pot with a torch so they come busy to the light, as brine shrimps and I can catch them easily.
If they are older and the pot need to be resheduled, I see also dead ones swimming at the water surface. I think then we must be careful. I put the water through a nauplia sleeve and try to keep the living ones to put them back in the new water, but they write that you shouldn’t clean the pot.
Then it takes some days and good moina are swimming again at the water surface.
Nice little food! 🙂Hallo Davy!
I will also try with light and see what happens!
Till now I didn’t use a special light, just the normal light in the room…Davy, did you contact that guy Jean Luc LAMBERT who offer life food to the forum? Peter Finke told five month ago about it.
Ah, he is a member here! I will recherché the living food he offers and then contact him. He has answered one post, about dero worms if I’m right!
My own Moina culture method has been OK but results in a variable supply. Numbers will build until there are absolutely zillions of them, then recede until there are only a few hundred or so before building again! I’d like to achieve a more dependable supply and so I’m going to try your method, Deepin Peat. To that end I’m making myself a guide based on the information that you have kindly offered in this thread.
One question : presumably a culture based upon your method doesn’t continue for ever? So is there an optimum duration that you’d allow a culture to run ; and how do you tell if a culture requires renewal ‘early’, as it were?
I have two bowls from one “starting material”, since about three months.
In one of the bowls I had the impression, that the supply was rather slow already (perhaps not enough water chance, or a “burn out” of the moina, don’t know.
Now I had ordered another starter set moinas and done them most in the one bowl and some in the other.
I have switched out again the light, i have no special seaweed for the moina, so I feel that the normal day light in the room will be enough for my moina ;).
Again here we see, that there are several methods to get a satisfactory result and not just one 😉
[quote=”Vale!” post=3760]My own Moina culture method has been OK but results in a variable supply. Numbers will build until there are absolutely zillions of them, then recede until there are only a few hundred or so before building again! I’d like to achieve a more dependable supply [/quote]
Well, this is completely normal. We have to realize that this is how it works in nature with most of the populations of any creatures. Only what we see with Moina is extreme example of how it works, becouse Moina is transfering close to 70% of the total energy income in to the reproduction. What we can learn form this… As long as there is enough food and space and the envinronment factors are within the boundaries for the species( polution, temperature,oxygen, some light), the population will grow. With Moina this growing population typically consists of females only and these females are literally cloning themselves (you can try and start a population with a single female), so the more females there are, the faster the growth of the population. This is the stage of the population that we need to achieve to get enough food for the fish and we want to keep this going. Because we work with a closed system, at some point the population will reach the breaking point which means there is not enough of something( food, oxygen, space) or to much of something (waste products). Mostly it will be lack of oxygen and to much of waste product. Than almost all the organisms would die and the population will colapse. But even before that happens, we are getting to some unwanted field. Many organisms will stop the reproduction before their populations would colapse. Moina will only make changes to the process. Once the environmental conditions start to deteriorate, the parthenogenetic females give birth to sexual females and males. The sexual females start to produce ephippia (the resting eggs similarly as Artemia does). These will sink to the bottom and wait for better times to start the population again when conditions are good (in theory you should almost always be able to get some moina again if you let the bucket dry for one or two weeks and add some aged water) . Sexual females may switch back to the parthenogenetic reproduction any time, they only need one moulting for that but compared with a lot of Daphnia, parthenogenetic females of Moina can not switch to sexual reproduction, they need to be born as sexual females to have that ability.
So back to your question 🙂 My point with feeding the living algae to Moina si mainly much slower deterioration of the the environment becouse the unconsumed food does not polute the water and it is constantly available as high quality food. Also it is one of the natural foods so its very well digestible for Moina which again leads to less waste products and therefore less polution of the water. Also some algae and cyanobacteriae contain very valuable nutrients that work as probiotics, growth factors and color enhancers for the fish as well as source proteins and fats in the very form that is best for the fish. Thats for the algae.
What you need to do to keep the culture as we want it, so with parthenogenetic females only and constant reproduction, you need to harvest enough Moina and exchange enough water often enough (on daily basis if needed). This way you should be able to maintain the culture for quite a long time. Of course there is a catch. With partial water changes you only dilute the waste products to some extend. Imagine that you have 100% of polutants in the water and than you make a 50% water exchange with absolutely clean water. 50% of the previous polutants are still in the bucket and Moina will add to it again before you make another water exchange so the levels of the polutants are still growing, the whole process is just slowed down to some extend. Some day you will get to the point where these substances will reach sexual reproduction inducing levels or in the worst case kill the culture. Thats why we need to start the new cultures over and over. If you want continous and effective production, you need to built a drop system. You would start with algae cultivation medium that drops to the tank where algae are cultivated and then algae drop to the tank with Moina and Moina drops in the bucket or sieve where you gather it for feeding. This is how it is done in commercial hatcheries. I hope that helps. Sorry if I have to many spelling mistakes in the “article :D”, I am not patient enough to go trough it couple times.[quote=”Vale!” post=3760]So is there an optimum duration that you’d allow a culture to run ; and how do you tell if a culture requires renewal ‘early’, as it were?[/quote] Sorry, did not answer this. This is the hard part that you need to learn from experience, so it is best to run several cultures and keep them on different densities. The same with algae. It is very dependent of how much and what you feed it (and as well as with the fish, you need to learn to feed just enough dependent on the density), the atributes of the starting culture (some populations will be able to survive under worse conditions then others) That is why it is best to collect for example Rotifera inoculations from muddy puddles. Lab Moina cultures may be much more sensitive to polution than some wild Moina you would collect yourself and vice versa.
Deepin’ peats remarks are exactly to the point. Moina is a very good and potentially fast growing food for Paros of nearly each age (from very small to adult), but they need more attention than e.g. Daphnia. You cannot culture them for months in the same water. But there are different methods possible.
I tell you mine: I kept them in small shallow vessels of about one or two liters each with some (but not much) artificial light and fed with yeast. No aeration; it’s contraproductive. I had at least three or four such vessels at the same time. (I never tried bigger and deeper vessels with success, but I know it’s possible, too). Kept this way they are very productive but very instable too. They need nearly daily care (= food supply). If you are absent for three or more days the culture is at the edge of death if not fed regularly. Feeding by algae results in a slightly minimized reproduction but makes the culture a bit more stable, although not very much. The necessity of starting new cultures is a constant task; I did that every week or ten days with the oldest vessel. I did not clean the vessel completely fed but reduced the free floating debris only. With this method I had a constant high production and could feed all my Paros in more than thirty small (12 liter) tanks, including growing young of many species.But longer absence or neglect of the constant changes of water/of vessels will definitely result in a catastrophe. The method is good for high production but there is no stability for longer periods of neglect. This is quite different than with Daphnia which need much less attention if kept in larger vessels even with irregular food supply and a better oxygen content than is necessary for Moina. Therefore, Deepin’ peat is fully right in pointing out the need for water change and the need for continuous beginning with new cultures. This is indispensable with Moina. If you manage to find a habit suitable to your presence and awareness, Moina is an ideal food for Paros over many years. If you don’t, it’s a nuisance since it will die out soon.
Don’t know why my last post came double …. 😉
And I forgot one thing to mention: yes, as you write, I also renew the whole cultures after a time, perhaps I should write diary… If the culture begins to become stinky, I pour the water through a sieve and cast the water away. Yes, I also don’t clean the bowls. Fill up with used water. Tap or osmosis had made no difference for me, and of course, put at once the sieved moina into it. After two or three days, culture is ready again.
By the way, in the tank I had put new moina in, I found before renewing many dead moina at the water surface (I thought they were dead, because they didn’t move. So I sieved them away before I caught the living ones to renew the culture …
But it makes also a difference, how many tanks you have to supply 😉 … I have just four, so I guess an extensive moina breed is sufficient for me.
Hey,
you can just use it with the culture solution, its no problem. If you want to separate it, either let it sediment in the bucket and use air tube to drain it or if you need just clean algae, you can use labarotory filtration paper and a cone. Than you can even rinse it, but if you use it for Moina it is not necessary, just use like 1/2 a litre of algae solution for every 10 liters of Moina culture and keep the water a little green. Add when you see it is clean again.
- You must be logged in to reply to this topic.