Newly hatched baby cories!

[Colin_T]

Livebearer fry are huge compared to most egg laying fishes. Labyrinths (Bettas & Gouramis), tetras, barbs, rainbowfish and most catfish all need infusoria or green water for at least the first week of life. Once they have grown a bit they can eat the newly hatched brineshrimp but the fry need to be big enough and be able to get the food into their mouth.

Generally the longer the egg takes to hatch the bigger the fry and the more likely it can take newly hatched brineshrimp from day 1.

 

[FishGuest5123]

Livebearer fry are huge compared to most egg laying fishes. Labyrinths (Bettas & Gouramis), tetras, barbs, rainbowfish and most catfish all need infusoria or green water for at least the first week of life. Once they have grown a bit they can eat the newly hatched brineshrimp but the fry need to be big enough and be able to get the food into their mouth.

Generally the longer the egg takes to hatch the bigger the fry and the more likely it can take newly hatched brineshrimp from day 1.

But my goldfish aren’t livebearers. Here’s a pic of my tiny fry. I’m confused.

Livebearer fry are huge compared to most egg laying fishes. Labyrinths (Bettas & Gouramis), tetras, barbs, rainbowfish and most catfish all need infusoria or green water for at least the first week of life. Once they have grown a bit they can eat the newly hatched brineshrimp but the fry need to be big enough and be able to get the food into their mouth.

Generally the longer the egg takes to hatch the bigger the fry and the more likely it can take newly hatched brineshrimp from day 1.

I’m sorry but I’m still confused. My goldfish lay eggs and they hatch in 3 days. Here’s a pic of them.

 

[FishGuest5123]

But my goldfish aren’t livebearers. Here’s a pic of my tiny fry. I’m confused.

I’m sorry but I’m still confused. My goldfish lay eggs and they hatch in 3 days. Here’s a pic of them.

I’m sorry. You’re right. I fed mine Hikari First Bites for the first week and then started the brine shrimp. My memory was failing me. Forgive me.

 

[Colin_T]

Theoretically goldfish fry should not be big enough to eat newly hatched brineshrimp. If yours did then you either had a very small strain of brineshrimp or your goldfish were more than 1 week old.

Brineshrimp come from different areas around the world and some strain/ brands are bigger than others. San Francisco Bay brand is meant to be smaller than most varieties. There might even be smaller varieties, which could potentially be small enough for newly hatched goldfish fry to eat.

The other possibility is the fry that survived are male. In most fish the male fry have slightly larger mouths and slightly bigger bodies than females. This might suggest the male fry were big enough to eat some of the brineshrimp and that got them through the first week, but most of the females died from lack of food.

My memory was failing me. Forgive me.

All good, I have old timers disease too. Now, what are we talking about?

 

[IndiaHawker]

Thanks so much for all the help! Few things I meant to reply to but will get back to that another time; for now I just have an urgent few questions:

- Babies seemed to be doing fine, a few deaths but assumed that was normal considering the sheer amount of babies? However as of last night/today a lot have died. Friday night and again on saturday I fed the egg mix (kept in fridge, used within 24hrs). Saturday the hikari first bites came and been feeding that. Throughout this time three beech leaves have been in there hopefully developing infusoria (reading contradictory things about how long they take to develop). However a load seem to have died - could this be due to lack of feeding or overfeeding?

- Have been struggling to keep the breeder box clean. Couldn't manage to remove all unhatched eggs, tried to but couldn't get them separated from the many babies - any tips? Plus although been trying not to feed too much (did likely misjudge the egg and overfeed on friday) and trying to syringe debris out of breeder box there is still visible debris. My gut says that the deaths are down to bacteria so I have a new plan which I need advice on.

Seeing as I feel like it's now at a point where if I don't take drastic measures the rest will die anyway, I'm wondering if this will help. I'm thinking of transferring the remaining fry, or just some of them, to a small plastic bowl. It wouldn't have a light fixture or heating/filtration. They would get natural daylight and be at room temperature of minimum ~18C. I would change the water regularly by syringing out muck and replacing water with tank water.

Does this sound like a good idea or not? Worth trying considering the foreseeable fate of the remaining babies anyway? Just want to give them the best chance I'm capable of. I guess at least my adult fish will have a tasty healthy snack tonight

EDIT: Forgot to add - my air pump has two outputs so can put a bubbler in the separate fry bowl if helpful? Also my bristlenose plec has been sucking onto the breeder box very frequently since I covered it in a sock - good/bad/neutral?

Please/thanks!

 

[Colin_T]

It is going to take at least 3 weeks before any infusoria appears in water containing rotting plant matter. Do not waste your time putting plant leaves in a rearing container for this purpose because they only add ammonia to the water and there will be enough of that from the food.

If you are making an infusoria culture, think of it along the lines of cycling an aquarium. In an aquarium it takes a couple of weeks for the first colonies of filter bacteria to appear in the water and build up in sufficient numbers to get rid of the ammonia and convert it into nitrite.

With infusoria it takes a few weeks for bacteria to build up in the water and start breaking down the plants leaves. If the leaves are crushed up or cut into small pieces they break down faster, but it still takes a couple of weeks for the bacteria to build up in numbers.

Back to the filter...Once the first colonies of beneficial filter bacteria have built up in sufficient numbers, you get new bacteria growing in the filter and these break down nitrite into nitrate. These new bacteria take a few weeks to build up in numbers before they can convert the nitrite into nitrate.

With infusoria cultures, the bacteria take a couple of weeks to build up in numbers and then it takes several more weeks for the infusoria (normally paramecium) to arrive in the water and start to grow. The infusoria eat the bacteria and gradually build up in numbers.

So you need the plant matter to break down, the bacteria to build up, the paramecium to arrive and grow, and then after about 1 month you have a decent amount of infusoria.

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If you are losing fry, they are either starving or dying from poor water quality.

You should have a small air operated, established sponge filter in the rearing container to help keep the water clean. If you don't have a filter then make sure there is an airstone and change at least half (preferably 3/4) of the water every day. Refill the rearing container with water from the breeding tank.

Because the fish are dying, I would drain most of the water out and replace it now. I would drain it again in 12 hours time and refill it. Then I would do a 50-75% water change each day.

Use a piece of air line and syphon the water out of the rearing container into a white bucket so you can check it for fry. If there are any fry in the white bucket, use a small plastic container to scoop them out and put them back into the rearing container.

Once you have drained out most of the water, uneaten food, fish waste and dead fish from the bottom, refill the rearing tank.

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If you are adding new food, make sure you continue to feed the old food for at least 1 week after the new food has been added to make sure all the fish are eating the new food.

 

[IndiaHawker]

Thanks so much for the help everyone! Been using a combination of all the advice and what I have to work with, and they currently appear to be doing well! Since moving them to the separate bowl I've only had possibly one or two deaths and the rest appear to be eating, slightly growing, and generally doing well. No filter so been using an air stone and using a pipette to remove debris which is working pretty well, and changing most of the water daily with my tank water.

Only question I have for the minute: I've kept the same three beech leaves in with them since the day they hatched I believe in the hopes of developing infusoria. The leaves are now coated in a thick slimy layer - I've been avoiding cleaning it off in case this is what's meant to happen - should I leave it (excuse the pun haha) or clean it off?

Please and thanks!

 

[Byron]

Thanks so much for the help everyone! Been using a combination of all the advice and what I have to work with, and they currently appear to be doing well! Since moving them to the separate bowl I've only had possibly one or two deaths and the rest appear to be eating, slightly growing, and generally doing well. No filter so been using an air stone and using a pipette to remove debris which is working pretty well, and changing most of the water daily with my tank water.

Only question I have for the minute: I've kept the same three beech leaves in with them since the day they hatched I believe in the hopes of developing infusoria. The leaves are now coated in a thick slimy layer - I've been avoiding cleaning it off in case this is what's meant to happen - should I leave it (excuse the pun haha) or clean it off?

Please and thanks!

I have never seen that with the oak leaves I use. They feel slippery to the touch which is normal. Did you rinse off the beech leaves? If this slime is whitish, it may be fungus; there are good and bad species of fungus, so to be safe with fry I would remove these leaves and replace them with others. Rinse well, make sure there are no bird droppings and such.

 

[IndiaHawker]

Hey I'm back again! Hadn't posted in a while as been busy and haven't really needed to - babies still alive! Not all of them unfortunately however still have about 20 and seem to be doing well. If my calculations are correct they're just over five weeks now, the only thing I'm worried about is they seem to be growing quite slowly and look smaller than pictures/videos I've seen of four-week-old babies. The deaths I've had since last posting I think can mostly be blamed on myself, I've done my 100% best and tried to be vigilant with the daily water change however there were one or two periods where I'd been out and skipped a day and unfortunately lost some due to my own wrongdoing. However I've been really good, especially lately, with changing almost all of the water daily, refilling with water from the tank. I gave up with the infusoria after finding out the stuff on the leaves wasn't normal (I had rinsed them very thoroughly beforehand), and I've been getting the same sort of stuff still growing on the air 'stone' in with the babies (ordered more replacement felt soon so hopefully that'll help) so been cleaning off the best I can. Lately I've only had the occasional day of finding one or two dead, I've been changing about 95% of water daily including using a pipette to siphon out as much remaining debris as possible so unsure why. Been feeding adult food lately as they're taking it, going between spirulina flakes (like at most one small flake crumbled up) and one shrimp pellet at a time - should I still be feeding them the hikari first bites to help them grow maybe? Help and advice really appreciated, please and thank you!

 

[Colin_T]

You want to feed them newly hatched brineshrimp, small worms (micro, grindal and white worms), and very small pieces of raw or cooked prawn. Feed them until they have huge bellies and look like a pregnant guppy. Make sure you feed them at least 3 times per day and preferably more. Keep doing big water changes and keep the water warm (26-28C). When they get bigger you can reduce the temperature to 24C but you want it warm for the first few months.

There is info in the following link about hatching brineshrimp eggs. Get some dry brineshrimp eggs online or from a pet shop and hatch them out. The fry will get orange bellies when they are eating the baby brineshrimp.
http://www.fishforums.net/threads/back-to-basics-when-breeding-fish.448304/