Using brig snail to sustain fry

[kimmisc]

I am thinking of breeding some harlequin rasboras. I set up a 5g minibow with a sponge filter and moved all the anubias nana I have into this tank. I put my brig in and seeded the sponge filter from her old filter media.

My plan is to keep her in for a while until the tank is more established, and maintain the pH and calcium levels appropriate for the snail until I add the rasboras.

If I then bring pH down over a few days, then add the rasboras (hopefully they'll breed)...

1 - Will a combination of the apple snail and liquid fry food be enough for the fry? I work 40hr weekends so if they're still very needy when a weekend comes, they'll be dependant on infusoria from the snail for 17-18hrs at the time.

2 - The low pH required to breed rasboras isn't good for snails, so this is the one reason I'm reluctant to use her for this. So I wonder how long this infusoria they produce lives on if the snail is removed. How long should the pH be kept low for the new fry? Is there a way to keep the infusoria going strong after removing the snail, that won't in turn make the water bad for the fry?

I read all about culturing infusoria, but it won't help much if I'm not home all day to put it into the fry tank. So I am trying to increases the infusoria IN the tank so they will be okay between feedings.

 

[Star_Rider]

I would guess..probably not but depending on how many fry you have..

fry tend to blast thru infusoria quickly atleast I found out with my angels.

even if you fed other source food they would tend to deplete the supply to the point where it would not sustain the fry.

 

[malken]

why not try for green water? or am I incorrect in my memory that GW is fantastic fry food?

 

[kimmisc]

why not try for green water? or am I incorrect to assume that GW is fantastic fry food?

That was going to be my next question! I've never had green water before. How should I go about doing that? Just leave the light on for more than 12hrs a day? 24hrs? Keep the plants in? Add an imbalance of ferts? I don't really know how to produce it on purpose.

Just looked it up, and everything I find says to culture it an feed a few drops at a time. Would allowing green water to develope in the tank make the water too foul for the fry? And the daily water changes the fry require combined with a normal lighting schedule wouldn't deplete the green water too quickly?

 

[kimmisc]

I am going to try to time this so the weekend they have to go without frequent feedings will come when they are already 4-5 days old. I'll just have to see what happens.

 

[kimmisc]

Okay I removed the snail, increased the lighting duration (to match daylight on a summer day.. 7am to 9pm), and also started 2 greenwater and 1 infusoria culture in a window. I will try and see if I can keep green water by using long light periods and increased nutrients while still keeping the water changed daily for fry. I doubled up on plant nutrients since I have so many anubias in there too. I'll have the cultures in the window for backup. I think the greenwater WILL be much better because it can remain in the tank and available for longer periods without fouling the water as badly as other foods (ie.. egg yolks, powdered flakes)... if I provide the right conditions for the GW to live in the tank rather than die and decay.

 

[wataugachicken]

i'm not entirely sure, but i think that when using green water as fry food, you culture the water separately and then add a small amount into the fry tank. that way the water stays clean for the babies. i don't think you try to make the fry tank green.

 

[closer2fine]

I asked this on another board & this was one of the answers I received:

Quote:Author: Rob Torrens
Date: Friday, March 27 2002
Using Apple Snails in Fry Tanks


Just thought I would let people know about, what I consider, an excellent use of apple snails (I also presented this information at the FNZAS conference held 2001 in Hamiton).

People who have tried to raise small fry have probably come across the term infusoria, used to describe some sort of mix of microscopic creatures that the fry will feed on. Not so many people know that Apple snails are also called Infusorial snails.

They have gained this 'Infusorial Snail' name due to their gluttonous ways. Apple snails are very good at eating but not so hot on the digestion side of things. This means that the snail poop, having some nutrition left (and being semi-digested) encourages the growth of infusoria.

Now onto the use of these infusorial snails in the fry tank. One of the major problems that people trying to raise fry have is water pollution due to uneaten food (perhaps a thin layer of LiquiFry on the bottom of the tank that we can barely see) and decaying fry corpses (as there often seems to be a few that just aren't as robust as the other fry and end up succumbing). If you have an apple/infusorial snail in the tank they efficiently clean up the uneaten food and dead fry while leaving the live fry alone.

So not only are the snails keeping the tank clean for you but they are also encouraging the growth of infusoria on which the fry will feed.

Now I'm not saying that having an Apple snail in the fry tank means you can get away with not doing regular water changes - just that the water changes don't need to be quite so frequent. Nor can you rely on the infusoria growth to be the sole food for the fry.

It has been suggested, that while the snails don't attack live fry, the have been known to eat fish eggs - so you may want to consider only putting them into a tank once the eggs have actually hatched (I have still successfully raised fry from a breeding tank where the snails were present at all stages though).

One precaution you should take is that when you are feeding the fry take the time to check that the snail is still active. Why? A dead and decaying snail can wipe out tank of fry quite easily if it goes unnoticed - particularly in small tanks.

If the fry are open water swimmers and don't eat any of the food that settles on the bottom of the tank, you may want to keep the snail in there as they grow. On the other hand if the fry happily clean up food that makes it to the bottom of the tank then you may consider removing the snail once the fry have reached a larger size as the snail may out-compete the fry for the food. Or alternatively reduce the number/size of the snails you are using.

I put down my success raising pygmy corydoras fry to my use of apple snails. Other members of our local club have had these diminutive cory's spawn and the eggs hatch, but then the fry have died a few days after absorbing their yolk sac - leading to the believe that they starved due to a lack of approriate (sized?) food. It should be noted that these people have rather clean breeding tanks, without apple snails. The only significant difference I can spot between their unsuccessful setups and my successful setup is that I had a couple of apple snails present that had caused the buildup of about half an inch of snail sediment (full of infusoria) - with all of this microscopic food available they were able to get past the critical phase and begin taking larger fry foods such as microworms

I also raise corys and applesnails hatchlings togethor. I hope this is of some interest to you.


and here is what Stijn says:


Quote:When there are many apple snails in a tank, the water tends to become cloudy because apple snails have a large amount of microorganisms in their intestine, which help to digest the food, and which are expelled with the faeces. These micro-organisms (amoebocytes) should not cause any harm to the fish and can even serve as a food source for young fish. Fresh food (lettuce etc.) are more likely to induce this micro-organism based clouding of the water.

 

[wataugachicken]

that is very neat

 

[soobie]

...I had a couple of apple snails present that had caused the buildup of about half an inch of snail sediment (full of infusoria)...

If what he does works, who am I to say he's wrong, but half an inch of snail poop in a fry tank? Eep.