my ostracods

How big are the adult ostracods and how big are the cysts/eggs? Has anybody else reported them laying eggs on live animals? I wonder if that's a natural behavior or just an artifact of being crowded in a container without enough other suitable surfaces to stick eggs to?

How big are the adult ostracods and how big are the cysts/eggs? Has anybody else reported them laying eggs on live animals? I wonder if that's a natural behavior or just an artifact of being crowded in a container without enough other suitable surfaces to stick eggs to?

Good question. I dont have much of my equipment with me right now, only my microscope. I can use software to get a good estimate of the size of the cysts, but alas, my computer died on me a little over a week ago.

So far as other people observing them laying eggs on live animals, I have no idea. I do remember reading a guide to invertebrates in which the author had seen them occasionally swarm objects in their native environments. He postulated that it was a breeding event. I dont think he ever cultured them though. I would guess that your assumpion is correct since I have only seen it in dense cultures.

That said, if they swarm heavily in natural settings, I wouldnt be surprised if a small critter or two got cought up in the mix. And that begs the question: am I triggering a similar swarming/spawning behaviour by keeping dense cultures or do they seek each other out and swarm naturally? Im not sure what makes them swarm, but they always do it in dense cultures at some point.

So, I'm starting my ostracod culture again...

Already have a hundred or so ostracods in a 2.5 gallon tank.

As an observational note, I saw what appeared to be twenty or so ostracods clustering on a piece of algae today. In a different tank. It looked similar to swarming behavior. But, they were not crowded in the least in that tank.

Edited by Auban, 19 July 2017 - 07:05 PM.

I am going to have to reintroduce myself to this topic. I find fish food quite interesting,and hopefully someday I'll be able to produce some of my own.

I don't know exactly what they were, but my gambusia pond used to have some tiny swimming invertebrates bust out in population every so often. They were always in a pack, even though, like your ostrocods, they had plenty of room to spread out.

I am going to have to reintroduce myself to this topic. I find fish food quite interesting,and hopefully someday I'll be able to produce some of my own.

I don't know exactly what they were, but my gambusia pond used to have some tiny swimming invertebrates bust out in population every so often. They were always in a pack, even though, like your ostrocods, they had plenty of room to spread out.

 

 

I used to grow lots of daphnia and even fairy shrimp, I seem to have lost the knack for some reason... 

I used to grow lots of daphnia and even fairy shrimp, I seem to have lost the knack for some reason...

I find that when you believe that you have lost the knack for something, you just need to keep trying and you will find success.

I used to set up a lot of tanks for growing live foods. I was thinking that I am just not good at it a more, but then remembered that I used to put much more effort into it.

My ostracods are doing pretty good now. They are on their fifth tank. Perseverance paid through.

Edited by Auban, 22 July 2017 - 08:07 PM.

I tried raising daphnia indoors, but it was just too much work. It's amazing how easy they (and ostracods) are in tubs or buckets outside, although I know that makes them irrelevant come winter.

Wow just replying here so I can find this later. @Gerald should I consider these little guys a risk in my aquarium or a food source? The last paragraph freaked me out a bit. I haven't seen diamond in the last few days as my water sprite is way over grown but now I'm worried they egged her 😨

Oops. Sorry I thought the thread was finished but I was likely just at the end of the first page haha. Where you observed in large cultures the seed shrimp swarming a live animal to lay eggs.

Edited by Cricket, 02 December 2017 - 08:50 AM.

Neither - from what i've seen ostracods are neither a threat nor a preferred food for Elassoma.  Some fish with strong jaws and teeth will eat them, but many fish don't.  The fact that they persist so well in Elassoma tanks should clue you in that Elassoma aren't too interested in eating them.  I've never the "swarming on live animals" behavior that Auban describes.  Swarming on dead ones - yes.

late response, but i agree with gerald.  the only time i have even seen ostracods bother live animals was in tanks in which i had concentrated very large numbers.  the fish that i saw them do this to was a small heterandria formosa fry, and i think it was kinda weak to begin with.  with fairy shrimp, they seemed to bog it down by sheer numbers.  but, in both cases, im talking about concentrations that are so high it is difficult to see the back of the tank.  in a normal fish tank, i have never seen them reach such population densities.  

Edited by Auban, 18 May 2018 - 07:20 PM.