Can Rotifers and POds coexist?

[cabrego]

Hi all,

I am wondering if anyone has experience with Rotifers and pods (copepods and amphipods).

Specifically, I am wondering if they can co-exist, or will one wipe out the other?

 

[GreshamH]

they'll be food for amphipods but I have co-cultured them with Tigriopus. To be clear, I did "SS" with Tigriopus, not "L" strain. I also did "SS" with artemia.

 

[cabrego]

they'll be food for amphipods but I have co-cultured them with Tigriopus. To be clear, I did "SS" with Tigriopus, not "L" strain. I also did "SS" with artemia.

Thanks for the response. I am investigating a massive decline in my rotifer culture and upon microscopic view it appears I have a significant number of amphipods in my culture.

For example in one drop that I was examining the amphipod to rotifer ratio was 5 to 1!


Is there anything I can do besides start from scratch?

 

[GreshamH]

Hmmmm I'm not sure of the larval stage size of amphipods but just maybe you could sieve them out using some screen?

They're incredible predators. They love copepods and rotifers

 

[phil519]

Thanks for the response. I am investigating a massive decline in my rotifer culture and upon microscopic view it appears I have a significant number of amphipods in my culture.

For example in one drop that I was examining the amphipod to rotifer ratio was 5 to 1!


Is there anything I can do besides start from scratch?

Curious why you think they are amphipods in your culture. Did you contaminate the rotifer culture with display tank water? The best way to avoid this is to just use ASW when adding more volume for the rotifer culture rather than trying to sieve your display water. I realize sieving saves $ but the alternative would prevent contamination.

A sieve should work - though you'd have to use maybe a 100 micron screen or something so that you don't catch the rotifers, but catch the predators.

Frankly i'd start over. PS - good tip is to always have two rotifers cultures going. So if one crashes or gets contaminated - you always have a back up.

 

[GreshamH]

I agree with Phil on starting over begin the safest as well as doing two cultures.

 

[cabrego]

Curious why you think they are amphipods in your culture. Did you contaminate the rotifer culture with display tank water? The best way to avoid this is to just use ASW when adding more volume for the rotifer culture rather than trying to sieve your display water. I realize sieving saves $ but the alternative would prevent contamination.

A sieve should work - though you'd have to use maybe a 100 micron screen or something so that you don't catch the rotifers, but catch the predators.

Frankly i'd start over. PS - good tip is to always have two rotifers cultures going. So if one crashes or gets contaminated - you always have a back up.

I am nearly 100% sure there are amphipods and probably copepods in my culture. I know this because I took a sample of water and looked at it with a microscope. I found there to be at least 5 or 6 large copepods for every rotifer. This was easy to estimate because there was only one rotifer each drop that I looked at.

I used fresh saltwater for the culture, I think I might have slipped up on utensils though, I used a turkey baster to syphon out some of the nasty gunk after the initial week of my culture, I usually rinse it, but that is the only thing I can think of. I use the same utensil for my fry tank that has tank water. My main tank is boooming with pods too. I will likely start over :thumbdown


the pods are amazingly fast, i noticed the rotifer wasn't harassed by the pods but there is definitely a massive decline in my population.

Out of curiosity how do you know amphipods eat rotifers. I have been doing research and have not read that anywhere.

 

[phil519]

ah - that's too bad you have to start over. I did also with my first batch because i way over-dosed on phyto on fouled my whole culture.

Frankly I barely clean my rotifer culture. When it looks really nasty at the bottom, I stop the pump, sieve out maybe half the bucket and place them in a new bucket with ASW and start over. Clean out the old bucket and done deal.

So in a nutshell I guess the copepods outcompeted the rotifers for food then? Interesting.

 

[cabrego]

ah - that's too bad you have to start over. I did also with my first batch because i way over-dosed on phyto on fouled my whole culture.

Frankly I barely clean my rotifer culture. When it looks really nasty at the bottom, I stop the pump, sieve out maybe half the bucket and place them in a new bucket with ASW and start over. Clean out the old bucket and done deal.

So in a nutshell I guess the copepods outcompeted the rotifers for food then? Interesting.

Well to be honest, I don't know exactly what has happened. I just know my culture has had a serous decline and I am trying to figure out why.

I don't think pods would out compete rotifers for food since pods eat mainly detritus but if pods eat rotifers (which I think they might) my rotifer culture was the biggest buffet they have ever seen.

I was going to a book I have and one recommendation is to let the ammonia build up enough to kill the pods and not the rotifers, some where around 1ppm I am guessing. I am not sure how I can do that since I have been using prime and my ammonia readings seem high already.

Also, I was inspecting more of my culture a few minutes ago and found that there are still SOME rotifers. I found at least 4 or 5 in a small sample I had ~ 1 ml. The entire volume is about 5 gallons. I am going to feed heavily tomorrow and see what happens.:thumbsup:

 

[GreshamH]

I know as I have watched them do so countless times

 

[phil519]

I no longer bother with prime or an ammonia badge in the rotifer cultures.

I did that at first but I have found just changing the entire bucket every so often works much better. I do not change the bucket though if I'm about to have a hatch.

good luck!

 

[GreshamH]

Not doing so (controlling ammonia) will drop your count if your not using live phyto (even with live it's still a concern). Its one of the main reasons people get low counts like 50/ml and not 1K+/ml. Our high density flow through system runs at around 5K/ml It looks like mud :lol:

Even with our flow through design we still use Cloramx on a dosing pump.

If you don't need such high numbers then it's not an issue This is one thing I always need to remember (not everyone needs billions a day, or even millions) when posting to threads like this

 

[cabrego]

Not doing so (controlling ammonia) will drop your count if your not using live phyto (even with live it's still a concern). Its one of the main reasons people get low counts like 50/ml and not 1K+/ml. Our high density flow through system runs at around 5K/ml It looks like mud :lol:

Even with our flow through design we still use Cloramx on a dosing pump.

If you don't need such high numbers then it's not an issue This is one thing I always need to remember (not everyone needs billions a day, or even millions) when posting to threads like this

Holy cow that is some serious rot throughput. Right now I don't technically need rotifers (fry are on bbs now) but the next hatch will. Yikes 50 per ml is low ?! lol

Right now I am lucky to find a rotifer in my 5 gallon bucket!

 

[GreshamH]

yah the gap between commercially growing them and hobbyist culture is unreal. We routinely ship billion plus orders to hatcheries that no longer feel the need to produce them themselves.

 

[phil519]

Not doing so (controlling ammonia) will drop your count if your not using live phyto (even with live it's still a concern). If you don't need such high numbers then it's not an issue This is one thing I always need to remember (not everyone needs billions a day, or even millions) when posting to threads like this

Hmmm - good to know. Time to get more ammonia badges. I don't have a need for that many rots - but it's still helpful to realize that tidbit. They seem almost indestructible to me.