Ostracod and fish fry

[Fishpony]

Hello all
I've got a quick question regarding ostracods (Seed shrimp) and fry. I've recently separated some baby platinum parrots (convicts) from their parents, they're about a day or two old, still in the wiggler stage, and relocated them into a HOB breeder box. Recently, I've noticed a disturbing amount of ostracods lounging around and on the fry. I've thrown in an airstone to help keep the fry moving around to simulate an egg tumbler and it seems to keep the ostracods off.

Wondering if the ostracods are dangerous to the fry? I can't do anything about it since if I return the fry they'll be eaten, and I can't let the parents raise them since their current tank setup means that once they transition to free swimming, they get sucked up into the filter. I can't get rid of ostracods either without harming the fry, nor is it worth it to try.
Thanks

 

[phreeflow]

Should be fine. I’ve raised fry in a tank full of them and never had issues.

 

[Fishpony]

Should be fine. I’ve raised fry in a tank full of them and never had issues.

Good to know, thanks.
My army shall grow

 

[andyroo]

I've got an infestation in the lemon tetra (breeding attempt) tank; i assume the ostracods will eat undefended eggs, so am thinking-through.
My experience is they'll eat pretty much anything including fish (gum-up the gills?) and live snails, particularly as the population explodes & they get hungry.

Please update, though I suppose you'd have told us if there was a problem.

Tetras generally don't take them as the shell is very hard, including these lemons. Cardinals will take them but not a favourite. The only thing I've seen really zone-in on them is red-line/Denison barbs, rocketing through the cloud like mahi on sardines. I could really see the skull muscles working the shells - fascinating.

 

[Fishpony]

I've got an infestation in the lemon tetra (breeding attempt) tank; i assume the ostracods will eat undefended eggs, so am thinking-through.
My experience is they'll eat pretty much anything including fish (gum-up the gills?) and live snails, particularly as the population explodes & they get hungry.

Please update, though I suppose you'd have told us if there was a problem.

Tetras generally don't take them as the shell is very hard, including these lemons. Cardinals will take them but not a favourite. The only thing I've seen really zone-in on them is red-line/Denison barbs, rocketing through the cloud like mahi on sardines. I could really see the skull muscles working the shells - fascinating.

I didn't have any success rearing them separately. The original batch of fry soon perished quickly after being separated. I'm not sure the exact cause of it, could have been due to it being the first spawn of a young pair of fish, or due to an ostracod infestation. I believe it is a combination of both. I have since moved the parents to another tank and have just been letting the fry grow as survival of the fittest, though no new generation has been achieved (disappointing, but I also don't want to be overrun with convicts).

I will note, I did observed ostracods crawling over the fry, as well as crawling around inside the hole in the head scars of my old flowerhorn. Whether they were actively harming my fish, or just acting like cleaners (ie, only consuming dead fry and tissue), I am unsure. Personally, I would think they are harmless, though unsightly and creepy seeing small creatures crawl around my precious fish.
I wish you well in your lemon tetra experiment.

 

[phreeflow]

That’s odd, I had no such issues. I had tons of seed shrimp with fry and they did fine. In fact, as they got older, they were always plump from eating the ostracods. Maybe we are talking about different things…are they the little critters that pulse up and down in the water column?

 

[RedRaven]

I bought a used planted tank a couple years ago plastered with them crawling around the sand, they even survive being eaten at times. I haven't seen them cause any harm to anything of mine and I think mostly keep their numbers in check with feeding and syphoning the substrate. I did see an explosion of them when I started using A biofilm "food" to help my Neocaridina shrimplets along.