Corydoras hastatus fry

[dave.h]

I have had a few batches of hastatus now but somehow seem to struggle raising them, they dont seem to be very active feeders.

I remove the eggs, most of them attached to floating plastic plants/java fern, and place them in a plastic container. Most hatch fine. The tubs have a large daily water change. They are fed on fine crumb dry foods.

Just to add, I have raised loads of Corydoras pygmaeus successfuly in the exact same way, and several other cory species. It just seems as if the hastatus need some other stimulant to become active and feed. Maybe the addition of other fry species if available?

[apistomaster]

Hi Dave,
I personally find it easier to raise Corydoras hastatus in a permanent breeding colony. I use a 20 Long set up with two sponge filters. One sponge filter is run in air lift mode, the other with a MaxiJet 600 power head rated at 160 gph/600lph.
I use a thin substrate and promote a heavy growth of Hornwort, Ceatophyllum, as these corys show a preference for laying their eggs in plants. I also supply rubble piles of hollow ceramic media to provide safe hides for the newly hatch and pre-metamorphosized larvae. Upon taking on the adult shape the fry join the larger school. I have begun with as few as 10 breeders but the numbers will grow faster if you start with 20 or 25 breeders. I feed my fish mainly live newly hatched Artemia nauplii but I store them in clean brine in the refrigerator to slow them down and keep them at their peak nutritional state.
I have stopped raising them for now but for 3 years I had them set up for breeding the tank produced over 300 fry which I sold while maintaining an average number of about 125 fish including larvae to adult breeding sized fish. I found production is best when I made 70% water changes every 4th day and kept the pH at or below 7.0 and a TDS of >75ppm. I keep them at a water temp of 82 to 84*F. Here are some glimpses of my set up.
Note also that I also have a colony of Cherry Shrimp sharing this breeding set up. I do this with all my Pleco breeding set ups and Dwarf Corys. I also raise C. habrosus in the same manor as I do C. hastatus but they are less productive but produce much larger fry.

[dave.h]

Thanks for your reply, I think I'll try and improve the chances of fry survival in the adults tank now.

Out of interest, why do you think that the fry struggle to survive when taken away?

[apistomaster]

Dave,

I think the fry do better when allowed to remain in the larger permanent tank with good Hornwort growth because the environment is far more complex and ecologically stable. The water life has established checks and balances among the various microbiological life forms, has much more stable and well oxygenated water. The microorganisms provide important sources of their first foods. On top of that, this species does own predate its own eggs or larvae. I raised an incredible 400+ of Corydoras hastatus in a just less than 3 years beginning with only 10 wild caught adults. Sold 300 and kept 100(approximately.) I retained a group of about 100 for restarting the breeding colony on short notice.
There is no risk of damaging the eggs from changing their environment nor handling which may cause losses that would not have occurred otherwise, too. The smaller incubation containers are subject to variations in temperature and degraded water quality that the larger established tank does not. The bottom line is that colony breeding works extremely well for Corydoras hastatus and it has the added benefit of being very productive while only using a single 20 long aquarium. I found the 20 Long to be the ideal size tank. I tried to use a 35 gal tank but it was less successful. I think for many larvae do better in water that is not too deep. I found this to be especially true of the Sturisoma aureum I breed. The depth is not a factor for any plecos I have bred but they produce very well developed fry which are quite large when they leave the cave. The 35 gal was 36 X 12 X 18H inches. This single colony tank makes everything very easy. All you need to do is harvest enough salable sized C. hastatus to prevent excessive overcrowding. Both the fry and adults thrive on Artemia nauplii and some live worms and frozen blood worms. Even the fry eat the earth worm sticks which soften to a mush in a short time.

BTW, Corydoras hastatus mature at an early age. I have seen 4 month old males join in the mating frenzy with the older males and females may begin laying eggs in as little as 5 months old.

[dave.h]

Thanks again. Unfortunately I don't use enough lighting for much plant growth. Java moss does ok though and I've seen fry come out of it before. I like your use of the filter media for as hidey holes.

[apistomaster]

Those mini-caves help increase the fry survival rates more than you can imagine until you actually try it.

[dave.h]

Starting to see a small result now. I've seen eggs laid regulary over the last month and seen freshly hatched fry. Tonight I've seen a fish about 10mm, maybe 4wks old or so. I haven't yet added the filter rings but I put lots of small rocks/broken plant pot pieces in there instead. I also put some Bee shrimp in with them and like them more than I thought I would

[apistomaster]

Sounds like your colony is off to a good start.
Good luck with your Bee Shrimp. I haven't had much success with whatever species it has been that I have tried twice.
Last time I bought some was in early November a couple years ago. I missed the delivery knock on the door so I didn't notice them until the next day. There were 25 and only a couple were dead but the water was very cold. I let them warm up all day in the room before I slowly acclimated them to their intended home. They died off very slowly so by the end of 2 months later I was down to a couple. The majority seemed to be fine for the first 10 days.
I think they are an interesting but rather small shrimp species. There are a couple different species of Bee Shrimp and I am not good at telling them apart.

[Heardmorebull]

Another reason that the fry survive better in tank with parents is passed immunity. Fry in tank with adults injest shed slime and epithelials while they are feeding. This kick-starts their immune systems by providing them exsposed material anb weakened pathogens. Fry separated from the colony do not get this boost. This makes them more susceptible to the gill infections that are murderous on frym

[apistomaster]

In the prior posts there are somethings called "venus factor" and "red smoothies to detox". Those are inserts not originally mine. Please correct.

I have said many times that I hatched brine shrimp then harvest them all.
That is more than I would need for a single feeding so I stored the unused shrimp in refrigerated brine. These stored well for at least 24 hours.

Change your water on some schedule. Every third or fourth day worked well for all the hundreds of species of tropical fish I've bred.

[Dave Rinaldo]

In the prior posts there are somethings called "venus factor" and "red smoothies to detox". Those are inserts not originally mine. Please correct.

jaws33 and CatfishGilly could be spammers. Only one post each.

[apistomaster]

Hi Dave,
Thanks. That hadn't occurred to me.

[bekateen]

I hit the report flag