Dino dormancy

[paraletho]

Does anyone have info or photos of dormant Dino’s, specifically Prorocentrum. I still have a light dusting in the sandbed and under the scope they don’t appear active and shape has changed to more elliptical. They don’t look like any diatoms that I can find and make up 90-95% of the sandbed fauna.

Next if it is the dormant phase do I try to remove the or just leave them be.

 

[paraletho]

@taricha

 

[EnterName]

This one didn't move and is elliptical imo. You can find other dinoflagellate images (but those were active) in my microscopy thread: https://www.reef2reef.com/threads/microscopy-thread.1138845/, Prorocentrum appears less common though apparently and this isn't a real cyst/dormant state, just imotile.

It's DIC microscopy though and not simple bright-field (at least my images), but other members also post their images and you are welcome to participate as well. :)

This species appeared in my ultra low nutrient system but never grew out of hand. Just a slight stain on the sand. It doesn't cause issues this way. It shifted towards Ostreopsis once nitrate and phosphate were slightly increased with ammonium bicarbonate and monosodium phosphate dosing. When dosing a bit more all dinos appear to vanish.

 

[jonelder68]

I had horrible outbreak of Prorocentrum few months ago. Took a good 2 months to eliminate. I was dosing silicates amongst other things. After they were visually gone I took sand samples and was only finding diatoms under the microscope samples for weeks. About 2 months later with no return or signs of them I turned off uv that was plumbed direct into DT. Within 24 hours I had Dino mats and snotty strings throughout. Surprise it’s back! Even with no slide samples showing them previously and nothing to the tank changing besides UV being turned off. So not sure this answers dormancy but they can definitely hide well and multiply extremely fast! That or when conditions aren’t favorable they are still present but possibly in such a small body size 400x magnification doesn’t pick them up?

 

[EnterName]

I had horrible outbreak of Prorocentrum few months ago. Took a good 2 months to eliminate. I was dosing silicates amongst other things. After they were visually gone I took sand samples and was only finding diatoms under the microscope samples for weeks. About 2 months later with no return or signs of them I turned off uv that was plumbed direct into DT. Within 24 hours I had Dino mats and snotty strings throughout. Surprise it’s back! Even with no slide samples showing them previously and nothing to the tank changing besides UV being turned off. So not sure this answers dormancy but they can definitely hide well and multiply extremely fast! That or when conditions aren’t favorable they are still present but possibly in such a small body size 400x magnification doesn’t pick them up?

They are always present in your tank, but in smaller numbers. I don't think it's possible to get rid of all of them (just like diatoms or cyanobacteria). Even chemical treatment will leave a small number alive for quite a while.

I don't know if the dinoflagellates that are commonly found in reef tanks form cysts at all. In a more or less healthy reef tank with stable temperature and salinity I can't imagine that they would need to. The cysts shouldn't be smaller than the dinoflagellate cells themselves and 400x should be enough to see them (I don't think I have ever seen one in my tank).

Are you sure silicate levels remained stable? Diatoms end up in the skimmer and manual filtration easily which slowly exports silicates over time. Nutrient levels might also have dropped again now that the UV no longer kills freely floating bacteria.

 

[jonelder68]

They are always present in your tank, but in smaller numbers. I don't think it's possible to get rid of all of them (just like diatoms or cyanobacteria). Even chemical treatment will leave a small number alive for quite a while.

I don't know if the dinoflagellates that are commonly found in reef tanks form cysts at all. In a more or less healthy reef tank with stable temperature and salinity I can't imagine that they would need to. The cysts shouldn't be smaller than the dinoflagellate cells themselves and 400x should be enough to see them (I don't think I have ever seen one in my tank).

Are you sure silicate levels remained stable? Diatoms end up in the skimmer and manual filtration easily which slowly exports silicates over time. Nutrient levels might also have dropped again now that the UV no longer kills freely floating bacteria.

Silicate levels were good. Though I quit dosing heavy about a month ago now just do a weekly dose. Nutrients besides first of now 4 rounds of Dino’s have been present. Specifically PO4- .05-.1ppm & NO3 never below 10ppm. My tank just breeds Dino’s .

 

[paraletho]

The tank I am referencing is an 8 ft 460 gallon. It was dry manmade rock and special grade sand. Dino’s presented at 4 months and I was not prepared. By the time I got solutions to dose they were full blown snotty bloom. The tank is now 16 months old. The sandbed sweeper was a lifesaver because I could keep them knocked back. I am glad he came out with the double bulb version. It cuts my 2 hour treatment time to a little less than 45 minutes. This tank is in a public viewing area. It is an in wall setup in the foyer of a local high school.
I will try to get pictures tomorrow. Basically it looks as though the cells are elliptical with a vacuole in the center. They do not move and are a dusty red.

 

[EnterName]

Found another oval Prorocentrum image in my collection:

It was dry manmade rock and special grade sand.

Moe K (creator of the UV sandbed sweeper) is currently investigating how special grade sand might cause or amplify dinoflagellates.

I'm not entirely sold on that theory yet, but if increasing nutrients, a UV sterilizer, and silicate dosing doesn't appear to help, you could try mixing finer sand into the special grade or replace it completely. This is quite an expensive and invasive test, but if nothing else helps, it might be worth a try. Moe reports success with Fiji pink.
Note that you might need a lot of silicate in your tank to boost diatoms enough to actually make a difference.

Dino’s presented at 4 months and I was not prepared.

Dinoflagellates during the ugly phase aren't unexpected and often don't require treatment at all. I don't think that being "unprepared" is why you are still having issues. Don't worry about it :)

I will try to get pictures tomorrow. Basically it looks as though the cells are elliptical with a vacuole in the center. They do not move and are a dusty red.

Looking forward to seeing what you have got in your tank. The dusty red sounds odd, Coolia sp. is sometimes a little darker, but most dinos look light brown-ish. The lack of movement is pretty common in my experience, but very often you have a few individual cells that move, and others that don't.

(Diatoms and Ostreopsis sp. some cells are moving, others are not)​

 

[paraletho]

Yes that is my Dino. I find none of them now. I have decided after doing more online searches these probably are a species of diatom.

 

[EnterName]

Yes that is my Dino. I find none of them now. I have decided after doing more online searches these probably are a species of diatom.

Yes, those are (absolutely stunning) diatoms. I would be very happy if you post them here as well: https://www.reef2reef.com/threads/microscopy-thread.1138845/

Or if you allow me to post them (I will of course tag you and give credit)

I'm kind of envious because I would really love this kind of diversity in Diatoms in my tank :D

They will be easy to get rid of. No silicate dosing, proper de-ionization of the ATO water, and manual filtration :)