General Notes
Rotifer Cultures:
Rotifers are a living animal. Without oxygen, food and light they will die. They really need to be put into culture up to 24 hours latest after you receive them.
So BEFORE you purchase Rotifer cultures from us you will need to have already set up a system for culturing up a system for culturing them. If you are familiar with this type of culture you will know what you need. If you are
not I strongly recommend that you purchase a book or two on the subject. (see below). As much as I would like to keep
on selling you these cultures they will probably die unless you have experience in this sort of culture technique.
I include some basic instructions when I send out Starter Cultures (See Below)
Basic equipment:
a) Clean fizzy drinks bottles - 2 Litre or 1 to 5 gal. glass fish tanks or larger
b) Ridged air tubing (about 4 mm OD)
c) Air pump
d) At least 1 Liter of salt water mix (22 Parts per Thousand - 22 gms of salt in 1 Liter of fresh water) that is
24 hours old or longer
e) I do supply a sachet of food (RAGO) with the starter cultures. Live micro algae is the best food you can use but
if you do not want the hassle of culturing micro algae we recommend you use (RAGO). It is a complete food. It would be
almost impossible to raise the larvae of most marine animals using Rotifers fed on yeast alone.
Instructions for Culturing Rotifers:-
Ideal physical requirements of the rotifer Brachionus plicatilis. ("L" - Strain)
a) Temperature - 20 / 30 Deg. C.
b) Salinity - 10 / 22 ppt (parts per thousand) = density of 1.007 / 1.014
c) Light - 2000 / 5000 Lux at 16 Hrs. Dark / 8 Hrs. Light
d) pH - 7.5 / 8.0
These are ideal settings, however Rotifers can and do survive quite well outside these parameters.
Culture Container.
This will depend on your Rotifer requirement. I have used 2 litre fizzy drinks bottles, Demi Johns and 1 to 5 gal.
glass tanks or larger containers.
Culture Water.
We use rain water but you can use Reverse Osmosis water. De chlorinated tap water will also achieve reasonable
results. We mix this water with an artificial sea salt mix to give a salinity of 22 ppt (22 gms. of salt mix in 1 Litre
of water) This is about 1.015 SG. I use Instant Ocean but you can use any good quality salt mix. You can sterilize this
water after mixing in the salt by heating it in a microwave oven for a few minutes (about 75 Deg. C.) and leave to cool
to room temperature but we achieve acceptable results without this. The culture water, when mixed, must be left with an
air line gently bubbling in the container for 24 hours minimum to make sure it is mixed.
Preparing the Rotifer food - (RAGO)
RAGO comes as a dry powder. Mix RAGO at a ratio of 15 gms to 500 ml of fresh or sea water. Add 500 ml of fresh or
salt water to a screw top container and add the RAGO. ( The container should be larger that 500 ml). Shake the container
well then pour the mixture into a liquidizer and liquidize for 2 minutes. Put back in the screw top container and keep
refrigerated when not in use. (You can mix half or a quarter of the packet, if so adjust the water quantity
accordingly) NOTE: Shake well before use as some of the contents will settle.
Starting this culture
Based on a 250 ml Starter culture and 2 litre fizzy drinks bottles. Take a clean, 2 Ltr. fizzy drinks bottle and
add 1 Ltr. of Culture Water as prepared above and your 250 ml rotifer starter culture. Place a small diameter rigid
plastic air pipe, no air stone, connected to an air pump via a control valve into the container and start it gently
bubbling so that the rotifers are slowly turned over in the container. Add 0.5 ml of the prepared Rotifer food to the
Rotifer culture. (Shake well before use). (Day Two) add more clean culture water to your container to about 3 inches
from the top and feed with 0.5 ml of the Rotifer food again. From (Day Three) feed the rotifer culture when it clears
(about 1.0 ml or less). Not crystal clear but "clear" Keep the culture at roughly 20 / 25 Deg. C. After several days you
should see a fairly dense culture. Note that the Rotifers are difficult to spot if you have just fed them . They will
look like tiny white dots (Brown / black dots if you feed Micro algae) At this point about 5 / 7 days I recommend that
you start 2 more cultures by adding 2 litres of culture water to a clean plastic bowl. Sieve off the original 2 litre
culture, discarding the old culture water, (Do not let the dregs from the bottom of the bottle go into the sieve) Wash
the sieve in the bowl of culture water to remove the Rotifers. Divide the 2 litres from the bowl equally into 2 clean
fizzy drinks bottles.
Rotifer cultures have a habit of crashing (Dying) so more than one is a good idea. You can keep on multiplying these
cultures like this until you have enough Rotifers to meet your requirements. When you use the Rotifers for food you
would sieve off all but about 250 ml and then sieve off the remaining 250 ml of culture and wash it into another clean
culture container with 1 litre of culture water in the same way as you did to start your first culture. Start a new
Rotifer culture every week or two weeks at the latest.
I strongly recommend that you feed rotifers on live micro algae or RAGO, not because we sell these products but because
Rotifers fed on yeast alone will not be nutritious enough to raise marine larval animals. Over feeding with micro algae
is not as harmful to the culture as over feeding with a 'dead' food. To feed the rotifer culture with micro algae add
enough micro algae to the culture to tint the water green. Do this each day until the container is full. You should
then be able to harvest the Rotifers by siphoning into the small sieve provided. Siphon off all but 250 ml (Approx.)
and pour this residue into a clean container and start a new culture. The rotifer density can be controlled by feeding
once a day to just tick over or twice a day or more for higher densities. The culture of rotifers is not an exact
science, you will learn by experience what works for you.
Notes:
1) Whatever size container you use you must make a note of when you started it. The smaller the container the
sooner you will have to renew it to avoid crashes due to the build up of ammonia.
2) The Micro Algae that we use is Nannochloropsis oculata.
3) Remember a Rotifer is what it eats. If it is fed a high quality food it becomes a high quality food.
4) Under feeding with RAGO is better than over feeding. You can over feed with micro algae provided that the pH of
the micro algae is not too high, ideally it should be the same as the Rotifer culture. As with most Marine creatures
if you think you are starving them you have the feeding regime about right.
5) It will pay you to "wet" both sides of the 50 micron nylon sieve under a cold tap before you use it. Sometimes the
surface tension of the Rotifer culture water will not break down and the sieve will fill up and not allow any water
to pass. To prolong the life of the sieve always wash under a cold tap after use. Blast the sieve in the reverse
direction to the way it is normally used.
6) A Specific Gravity change of greater than plus or minus 0.007 send Rotifers in shock and possibly death.
Larger Capacity Rotifer Culture Procedure: (Similar to our method)
Equipment:
3 off 25 Litre buckets (We use 30 kg containers that the Instant Ocean comes in)
3 off Z type air lift tubes (See Drg. below)
Compressed air supply
Method:
Two of the containers are kept in culture while the third container is filled (20 Litres) with used sea water.
(we use either our shrimp system or fish system waste water) 'Cycled' for a week with no Rotifers but air flowing
in the air lift tube. This 'old' water is accumulated through water changes in the two systems we run. It is stored
outside in green plastic water butts. One of the culture containers is emptied each week by siphoning out most of the
Rotifers into a 50 micron nylon sieve leaving the muck at the bottom of the container. These Rotifers are washed into
the clean container. The used container is then cleaned out with household bleach and filled to the 20 Litres mark
(Just level with the top of the air lift tube) and the air lift is started. Using this method each container is in
culture for 1 week. To date we have not had a crash. Reducing the density of the sea water will increase Rotifer
reproduction.
Temperature:
These culture containers are not individually heated but attain the ambient temperature of the building they are
in. Typically 20 / 24 Deg C.
Lighting:
There is no specific lighting set up for these cultures although they do get some indirect day light.
Food:
We use our own food (RAGO) that contains amongst other things a number of essential fatty acids. We also sell it
to the public
You can, of course, use Live Micro Algae (Normally Nannochloropsis oculata) but we mainly use (RAGO). If you do use
Micro Algae be careful that the pH of the Micro Algae is not too high and shocks the Rotifers.
We mix 30 gms of (RAGO) to 1 Litre of fresh tap water then dose 20 ml of this mixture per culture container per day.
This gives an average Rotifer density of about 100 / 150 per ml. Feeding more frequently increases the Rotifer density.
You must remember that the food you give these Rotifer cultures is dependant on the nutritional requirement of the
animals you are going to rear, using the Rotifer as a vehicle for that nourishment.
Z Shape Air Lift:
The air is adjusted to give a steady flow of bubbles. This produces a gentle circular motion and keep the Rotifers
in suspension.
Basic layout:
If you have purchased RAGO see (RAGO) feeding instructions.
NOTE: For the good of your own Health DO NOT keep any live culture anywhere that it could
come into contact with food or utensils used for human food preparation.
Suggested reading:
1) Plankton Culture Manual - published by Florida Aqua Farms
2) The Marine Aquarium Handbook (Beginner to Breeder) - Martin Moe - ISBN 0-939960-07-9
3) Clown fishes by Joyce D Wilkerson - ISBN 1-890087-04-1 (Soft cover)
There are other books on the subject but these do give good, practical accounts of the methods required.
KEEP OUT OF REACH OF CHILDREN. NOT FOR HUMAN CONSUMPTION.
For the good of your own Health. DO NOT keep any live culture anywhere that it could come into contact with food or utensils used for human food preparation.