Live Daphnia for Corydoras

[Daphnia]

I'd like to get some help from anyone who feeds live daphnia to Corys. I have a small planted aquarium with 6 Bronze Corys (+4 Harlequin Rasboras) for a year now. I've just started to breed daphnia to supplement the diet of my lovely pets. So far I've tried 3 feeding sessions by tipping live daphnia right onto the bottom (using a sieve), but my Corys don't seem to be able to catch daphnia very well, not like it is supposed to be (https://www.youtube.com/watch?v=ZPZ_P04_PTk). Maybe they were raised on worms and don't know how to catch daphnia, or maybe they are out of practice due to the absence of live food during their first year with me. Next thing I'm going to try is injecting daphnia into the substrate (using a pipette) to a shallow depth and see if they can dig it out. I would be grateful for any other suggestions. Also I'd like to know if I am not just wasting my time trying to teach my Corys to catch live daphnia. Is it quite natural thing for them to do, and so they will come to it soon, or they have no chance because of lack of practice in earlier life?

[pleco_breeder]

Daphnia isn't normally a mainstay of their diet, so you shouldn't be expecting any kind of a frenzy from them. I used to feed daphnia in planted tanks containing adolfoi, habrosus, and burgessi (been a very long time ago, about 20 years) and would see them occasionally eat them, but never with any gusto. I always went on the assumption that if they really wanted them they would find a way.

With regards to putting them into the substrate, I would advise against this. Daphnia are planktonic and would quickly die if trapped in the substrate. I really think this would cause more trouble than good.

[Daphnia]

Thanks for reply and advise. I agree that injecting live daphnia into the substrate was a bad idea (I actually tried and saw it for myself). Next I've tried to release daphnia from a pipette just above the ground gently in front of their noses and it looked like they managed to get some. I suppose that live daphnia won't be widely recommended for Corys, if they normally had little success in catching them, so I'll keep trying for a while. However I must admit that I have gone with daphnia firstly because it seemed the easiest live food for me to start with, as I'm not prepared to breed worms in my house (yet). Now I'm looking into possibilities to get mosquitos to breed in garden barrels. I used to see glassworm in such barrels, but would Corys eat live glassworm? - e.g. if it is injected into the substrate like people do with brine shrimp (https://www.youtube.com/watch?v=8pUx6DHUz4A). And, is it possible to get a brood of bloodworm in garden barrels?

[dw1305]

Hi all,

........ And, is it possible to get a brood of bloodworm in garden barrels?

You can, you need to add some dead leaves to the water, and the barrels are better in the shade.

The blood-worms hide in little tubes they construct during the day, but you can harvest them at night from the water column.

I float a cork in the barrels, because I want mosquito larvae as well, but I'm not sure that the female chironomid midge needs to perch to lay her eggs.

cheers Darrel

[Daphnia]

Hi Darrel,
Many thanks for helpful response. I'll add leaves and cork - it would be great to get both bloodworms and glassworms in one barrel. Do you feed them to fish as they are, just washed under tap water and no other cleansing needed? I've read that they both are carnivorous and, therefore, clean and safe. Is that right?
Inga

[dw1305]

Hi all,

.....it would be great to get both bloodworms and glassworms in one barrel. Do you feed them to fish as they are, just washed under tap water and no other cleansing needed? I've read that they both are carnivorous and, therefore, clean and safe. Is that right? Inga

Yes I just give them a rinse in a fine fish net, and then tip them into a beaker of rain or tank-water to feed the fish.

I've never had Glassworms (Chaoborus spp.) in any of the buckets, but you get them in clean-water ponds in the winter. They are predators of Daphnia, Cyclops etc.

The mosquito larvae I get are from ordinary mosquitoes (Culicidae), and both they and the blood-worms feed on small microbial items.

cheers Darrel

[Daphnia]

Thank you very much, Darrel, I'll try to get all I can from now on. In addition to garden barrels I'm going to look for creatures in the abandoned water troughs in fields around my village and almost sure to find things there. It will be the first time for me to do that, so, I just want to be sure that I get this right: is there any chance of Ichtiophtirus cross-contaminating via birds that drink from the local river inhabited by wild fish and then from such troughs? On the one hand, I'm embarrassed that the question is too fussy, but, on the other hand, I'd be a fool if I introduce that disease to my aquarium.

[dw1305]

Hi all,
I've never had any problems with introducing parasites via live food, although I have inadvertently introduced Hydra, Planaria and Leeches.

cheers Darrel

[Daphnia]

I have inadvertently introduced Hydra, Planaria and Leeches.

Hi Darrel, and what did you do then? Did you have to eradicate them, or they are relatively harmless?

[dw1305]

Hi all,

I have inadvertently introduced Hydra, Planaria and Leeches.

Hi Darrel, and what did you do then? Did you have to eradicate them, or they are relatively harmless?

They aren't a major problem, unless you want to breed the fish. Planaria and leeches eat fish eggs, and Hydra fish fry.

Planaria and Hydra you can control with fenbendazole (I used Panacur worming tablets for dogs etc.). Details are in ("Weird parasite/worm":https://www.planetcatfish.com/forum/vie ... hp?t=45031).

Leeches I've just learnt to live with, and I reduce them via physical removal, the same tactics work for both leeches and Planaria.

Details are in ("Are these worms...: viewtopic.php?f=4&t=44066&p=300314#p300314").

cheers Darrel

[Daphnia]

Hi Darrel, Thanks. The creatures don't sound too scary.
I never intended to breed, instead, I used to fear that my Bronze Corys can spontaneously start to spawn just before I'm due to go away somewhere, and generally, that I haven't got a spare aquarium for young, no experience, etc., as I saw reports that well-fed Bronze Corys can spawn after every water change and someone couldn't stop them from spawning. However, now after editing my fish size here, I've realized that my fish are too undergrown (4 cm instead of 7 cm) and will, most probably, never breed. And that I should feed them with most nutritious food a.s.a.p. to recompense for the past year. Another cause for them being so small is probably the population density: only 0.8 l of water per 1 cm fish length (apart from 6Corys, I've got 4 Harlequin Resboras, the latter I'd love to have 8 but afraid to overcrowd even more). What do you think, from your experience, is it correct to suggest that my undergrown Corys will, most probably, never breed?

[dw1305]

Hi all,

...... However, now after editing my fish size here, I've realized that my fish are too undergrown (4 cm instead of 7 cm) and will, most probably, never breed. And that I should feed them with most nutritious food a.s.a.p. to recompense for the past year. Another cause for them being so small is probably the population density: only 0.8 l of water per 1 cm fish length (apart from 6Corys, I've got 4 Harlequin Resboras, the latter I'd love to have 8 but afraid to overcrowd even more). What do you think, from your experience, is it correct to suggest that my undergrown Corys will, most probably, never breed?

I've had stunted fish breed, but not specifically Corydoras.

I think you definitely need a larger tank as soon as possible, and I would keep them fairly short of rations until you have re-homed them in a larger tank.

cheers Darrel

[Daphnia]

Thanks, Darrel. But first I'll need to re-home myself in a larger house and earn more money ): However, I can do an immediate remediation by topping up the water level in the existing tank, which is actually bigger! I am terribly sorry for messing the size up, I'll measure its full height and not just water volume and edit now. With topping up it will bring my population density to the standard 1 litre per 1 cm of fish length. Another measure of density I used to rely on was 1 fish per 3 litres of water, but that must be either out of date or for some mini-fish ): ??? Anyway, my nitrate level is quite low, normally around 10 mg/l, all fishes active and often playful, they don't know they are stunted... Like owner, like fish

[AntonioAG]

My Corydoras Paleatus/pygmaeus go crazy for live Daphnia. It is the moina strain which is quite small (babies are smaller than brine shrimp) so they just suck them in mass. The daphnia usually congregate in the glass corners so the corydoras just glass surf and easily get them. I dont think they can eat it from the water column tho. I also dont know if the strain would play a role. I have never fed bigger strains like magna or pulex so I cant tell how those strains behave. I would expect it to be similar.
If I could I would definitely feed them something more "natural" like worms.
My corydoras all came from a fish store (if anything the pygmaeus are wild caught as the guy told me they came from Colombia or something) so I dont think it matters wether they "learnt" it early in life.

[Daphnia]

go crazy for live Daphnia. It is the moina strain which is quite small

Hi, it is so nice to hear from you. I'm glad to report that my Corydoras aeneus from the local store also are going now crazy for live Daphnias, which are also Moina strain (or, is it a different species?). Eventually I've trained them to eat from a pipette. In my Moina cultivator (10 l aquarium, +26 C) I catch the crustaceans by removing the back screen from the window (the cultivator is on a window sill), so the creatures trying to escape from direct sunlight will swarm into the least illuminated corner, from where I gather them into the pipette and then release at the bottom of the aquarium with fish. Otherwise the Harlequin Rasboras will eat all the Moinas before they reach the bottom for Corys. The learning success of my Corys was different in different individuals. Two females, Prima and Granda, have liked the pipette from very beginning and soon learned to suck directly from the pipette (especially, Prima). Two males, Ray and Mini, are catching Moinas released from the pipette, but aren't so bold to suck it directly. The other two, Premier the male and Booty the female, have been persistently hiding behind the wood and plants, afraid of the pipette, for 3 weeks. Recently I've started to culture and feed microworm from the pipette too, and, at last - Premier came to it two days ago. The next day he was right there without hesitation, as he finally understood that food is coming out of there. At the same time, Booty has lost interest to hiding alone, and came to the feeding place, but still, she was hiding from the pipette behind the tails of her siblings and failed to catch any food, it seems, but hopefully she'll come to it in nearest days. Have a go with a pipette - you might enjoy such sort of interaction with your pets!