Plankton Culturing

I have decided a while ago to try my hand at culturing phyto- and zooplankton.  It started out as somthing I thought would be easy and cheap, but I was quite wrong.  That being said, I am sure you can make it work for less, but that is not my way.

I will fill out the details of this endevour as I progress.  Below is a event log.

 

Date Notes Photo
27 Oct '11 Not sure but it looks like I lost my Rotifer culture.  I do not see any rotifers anymore.
22 Oct '11

Harvested 1.5L of both Nannochloropsis cultures, replaced with sterile saltwater.  Algae count were above 8 million cells per milliliter.  Harvested 70% of the rotifer culture as the density seemed high by visual inspection, and observation under the microscope showed that most rotifers had either no eggs or as single egg - as far as I understand that implies the culture has reached a plateau.

500mL of Nannocholorpsis was fed to the tank, and the concentrated rotifers were fed to the tank too.
18 Oct '11

Day 10 of the Rotifer culture and I finally start to see a much denser colony.  The population exploded when I started feeding them more heavily.  I think I have been overly cautious initially with feeding.  Since adding Nannochloropsis fills up the vessel faster than evaporation, I am forced to harvest them.  

 

I have harvested 1/2 of the culture, screened them through a 53µm filter mesh, and fed the concentrated rotifers to the tank.  Refilled the culture vessel with newly made saltwater. 
16 Oct '11 Drained 1.5L from left culture vessel, and about 500mL from right culture vessel.  Refilled with sterilised salt water with nutrients as the density seemed to have saturated (visual inspection).  Rotifer culture is starting to get significantly more dense, however nothing near the required 400 / mL at day 5 as per the manual.
12 Oct '11 Drained 1.3L of the right culture, and about 1.1L of the left culture of Nannochloropsis to sterilised containers.  Refilled with sterile saltwater.  Fed about 350mL to the tank.  Rest stored in fridge.
12 Oct '11 Relocated the rotifer culture to the third 2L vessel, and added 1.5L newly mixed, sterilised water.  Added 10 drops or RotiFeast and a little bit of Nannochloropsis.  A very slow bubble rate of 2 bubbles per second stirs the water.  Light is not intense.
11 Oct '11 Took 500ml from the left culture vessel and fed to tank.  Mixed 400ml new culture water and added to left culture vessel.  Added some of this Nannochloropsis to the rotifers, and stirred it.  Saw many that hatched. 
11 Oct '11 Left culture vessel has 7.5 million cells per milliliter, right culture vessel is at 6.7 million cells per milliliter.
10 Oct '11 Relocated the petri dish water with rotifers to a 500ml flat open container with 500ml of newly mixed saltwater.  Fed with more Nannochloropsis, just enough to colour the water light green.  I do believe I have visually seen one or two hatched rotifers.
9 Oct '11 At about 14:30 I added several drops of Nannochloropsis from the left vessel to the petri dish as feed for the rotifers.  Cannot yet observe any that have hatched.
9 Oct '11 Cell counting yielded approximately 4.6 million cells / ml in the left culture vessel.  The rightmost one could not be counted because 99% of all the Nannochloropsis cells are lumped together in small bundles.  
8 Oct '11

At 14:30 I started my rotifer culture.  The old petri dish from the algae disk was cleaned and filled ½ height with culture water (i.e. 1.015 sterilised water).

I took some culture water to add to the resting rotifer vial in order to shake loose and rehydrate the cysts.  This was promptly poured back in to the petri dish where I have placed it in the right corner of the phytoplankton culture vessels, where I hope the spill light from the 24W T5 would be sufficient to meet the 2000 lux requirement.  
8 Oct '11

I harvested 4 x 125ml bottles of algae which I placed in the refrigerator for protection in case my culture crashes.  An additional 200ml was harversted to start another 2L culture vessel.  The water is light green so I think the ratio is correct.  Then 500ml was fed to the display tank.  I have no idea if this is too much or too little, it would translate to about 11500 Nannochloropsis cells per ml in my tank.

The vessel on the left is the original vessel I started out with, that has now been dilluted by 1:4 times.  The vessel on the right is effectively a 1:10 dillution. 
7 Oc '11 Counting algae cells using a Hemacytometer, yielded approximately 8 million cells per ml.  My culture seems ready to split so I am preparing the next batch.
7 Oct '11 Even more growth.  Nice and dark now - can barely see the bubbles anymore.  
5 Oct '11 Culture is distinctly darker green.  Seems like the cells are multiplying just fine.  
4 Oct '11 The reactor itself.  
4 Oct '11 Added 30 drops of F2 nutrients to the 2L culture.
3 Oct '11 Closeup of the cells.  The dark line segments are bacteria.  Oh these cells are about 6μm in diameter.
3 Oct '11 Looked at a sample of the newly rehydrated cells under the microscope.  Noticed some bacteria swimming around.
3 Oct '11 Mixed 2L of sterilised water at 1.015 SG in plankton reactor with large bubble aeration.  Fluorescent light attached.  Placed a fan infront as the temperature reached 29C.  Temperature is now 24C.  After 4 hours of mixing I gently swobbed the cells from the gelatin base in the petri disk in to the water which covered it, and then poured this in to the plankton reactor.  The water is a uniform green colour.
2 Oct '11 Added sterilised (boiled in microwave for 7 minutes) water at 1.015 SG to petri disk with Nannochloropsis cells

Back to top