Rotifier protocol

[Indo Farmer]

Hi all,

I'm trying to get good reproductive rates and super high density rotifers, 3000/ml+. The reproductive rates are not what i would expect an i think there is something fundamentally wrong in my protocol.

I start at around 120/ml in 4 lrts adding 1ml/million individuals of rotigrow nanno four times per day, decent aeration. I change around 30% of the water per day and return the rotifier in the seive back into the tank. Have a floss down the side that is cleaned daily. Very slow increase if at all and peaks at 700.

Any tips are welcome. I think it could be because i am returning harvested rotifier to tank.

 

[VWD]

I have never return them to the culture. It’s been years since I’ve used rotifers. But I harvest and do if I remember 50 percent water change, feed and use what I harvested to feed fry.

 

[Indo Farmer]

Hi Vwd, that makes sense. We tend to return only when we're trying to build up the population prior to the spawning, but this is where the problem is. I'm currently working with a barramundi hatchery and need around 500 million rotifer for our batch. Do you think during the build up phase its better to discard the rotifer?

 

[VWD]

If you are trying to achieve large amounts. Take what you harvested and start another batch. It’s always good to have multiple going in the event you lose a batch. Like I said it’s been awhile but I always had two or more batches going . Harvesting and feeding my fry and a friends fry. It’s becomes a job.