Raising Corydoras Pygmaeus

[mikev]

I am having problems with raising Pygmaeus fry. Not a total failure, but inability to raise a large group. 5-6 fries per 2.5g raising tank work; attempts to raise 20-50 at once all failed, either a single fry survived or none at all. At the same time, some fry also makes it in the parent (single-species) 10g tank, but only 1-2 at a time.. this is perhaps 99% loss.

From the pattern, the cause is nearly certainly simply starvation: small groups find enough infusoria to get through the first crucial week, large groups don't. Perhaps this would work better if they were given a well established larger tank (10g, for example), but I'd prefer to find a way to feed them in a 2.5, if this is possible at all.

Food tried so far is artemia (obviously, useless for the first week), powder (APR and GP's), substrate from mature tank, squeezes from mature sponges (total loss on this experiment), plants from established tanks (java moss, najas).

Any idea what else can be tried? I doubt green water would do much.. what about paramecium? anything else?

Thank you!

 

[Harlequins]

I know how you feel,i had the same problem when i started saving cory eggs,i lost so many batches of fry when i had them in the small 4 gal tank especially the trilineatus fry...

Things started looking up when i ungraded the fry to a 10 gal tank,which i put mature media into the air driven box filter and slowly has the tank matured i ended up getting more fry surviving.
So when the pygmys started spawning,i first off decided to leave them in with the parents,has they didn't appear to eat the eggs...but did become apparent they ate the fry,has they did start disappearing
So i started saving the eggs and transferred them to the fry tank,at first i did overfeed them and ended up losing some,then gradually i had a batch of 15 eggs which all hatched and i managed to sucessfully raise them,they're now in my main tank.
I fed them a basic diet,feeding small amounts of tetramin baby powder or defrosted baby brine shrimp mixed in a little tank water and using a pippete put the food right to the bottom above the fry,has they got older i crushed up tetra prima mini granules.they grew quickly,bless them
Obviously water changes a while after feeding incl keeping the substrate clean,helps them thrive,stops any food rotten and the fry getting bacterial infections.
I still do daily water changes on my fry tanks which have numerous fry in,this encourages growth by removing the hormones they produce(from what i've read)
Heres a link to my breeding pygmys

Good luck don't give up,i thought i'd never get batches of corys to adulthood,but now i have lots of the wee things
Just my experiences

 

[mikev]

Thanks. At the moment, big scale (10g) experiments are not feasible, I am too short on space (should not happen with 80+ tanks, but does ). I think I'm giving up on figuring this out for now... instead, I simply started spreading powder food in the parents tank, and it seems to help: I saw five juveniles that hang with the parents already and some smaller babies hiding under moss. If they can continue breeding "naturally", even slowly, this is fine by me...

 

[the biffster]

might be worth growing some
infusoria to feed them on
boil some water place in a
large to medium jar and let
it cool the take some lettuce
leaves and blanch them leave
to cool once blanched the place
in the jar with the boiled
cooled water in once this is done
just stand on a window sill
in a few days time you should
see a cloud in the waster just
above the lettuce that is infusoria
you can draw it off using a peppet
and feed the same way

hope this helps the biffster

 

[mikev]

I'll try this... no need to grow infusoria, I have a culture going right now...had to wait for a good number of eggs which I now have.

(Not fully sure why I'm doing this they are breeding by themselves, the shoal already has twenty animals, plus small ones hiding in the moss... before long, the tank will be overloaded.)

 

[mikev]

to wrap this up:

it turned out that the reason I was having problems was the food -- it somehow managed to go bad despite being kept frozen and was killing most of the fry of any kind. Nothing special about c.pygmaeus.
Paramecium is unneeded. The fry grows fine on APR or Sera. I supplement the current group with microworms, but it does not seem to be needed either.

 

[Harlequins]

I'm glad you managed to sort out why

We all still learn along the way,i had lots of heartache over fry when i first started,but we get there in the end

I used to use firstbites,liquidfry,live foods etc,but now i use a mixture of tetramin baby powder and defrosted brine shrimp and that works for me and my fry

Good luck with future fry