Today, Friday, 13th of October(!), I started another test to finally clean up the myths
about aeration. Since the adults I have get enough oxygen by putting just 2 aqua leash
every few days (or even less), the oxygen content of the aquarium water can be fairly
low to maintain acceptable conditions for adults. But in order to provide suitable
conditions for fresh hatched nauplii and to ensure their survival until they mature,
a much higher oxygen level is required. The latter is subject of this test, to prove
that oxygen is the most important factor for nauplii survival and not other parameters,
such as salt quality, salinity and currently unknown parameters.
I took a clear water bottle, added about 35g of Artemia salt (for 1 liter of bottled
non-carbonated water), also added some liquid algae to provide food for the fresh
hatched nauplii as soon as their naturally provided yolk is used up.
After filling the bottle with the salt and the liquid algae I added some Artemia
eggs of the solar salt work "Salina di Cervia" in Italy (which I have harvested
in August 2006) and filled the bottle up with one liter of bottled non-carbonated
water.
19-DEC-2006: Oxygen experiment
Aeration of the oxygen test tank with an air-stone
Nothing special so far (except of the Artemia parthenogenetica eggs of Cervia),
but now I hooked up my small aquarium aeration pump, with a small pumice aeration
stone to ensure aeration 24 hours a day. Now the "tank" is sitting on a shelf,
is happily aerated and I expect the first nauplii to hatch within the next 12-24
hours. Note: Don't "bubble" too much with the airstone - only very little constant
aeration is necessary. Otherwise the bubbles might damage (emerging) nauplii or
prevent hatching completey. Use a flow control valve (available also at aquarium
shops) to control bubbling. Also only put the airstone at a max. of 2cm (~1 inch)
below the surface, otherwise it is too dangerous for the Artemia. They could be
thrown to the surface by bubbles and probably injured(?).
Test timeline:
DATE
TIME
13-OCT-2006
18:00
Test tank setup
14-OCT-2006
23:00
First nauplii are visible :-)
15-OCT-2006
18:00
More and more nauplii are visible! :-)
16-OCT-2006
18:00
Now plenty of nauplii are visible! :-) Also
added 2 drops of liquid algae
18-OCT-2006
23:00
100s of nauplii are swimming happily around
and are growing. So far so good!
20-OCT-2006
23:00
Added 2 drops of liquid algae
23-OCT-2006
23:00
They are all doing very well and today
I added a small scoop of algae powder the first time.
26-OCT-2006
13:00
Added one small scoop of algae powder. The
metanauplii are now about 1mm in size. Hard to count, but I think there are about 200 in the bottle.
29-OCT-2006
13:00
Added one small scoop of algae powder
30-OCT-2006
22:00
Plenty of meta-nauplii are swimming happily
around the tank
31-OCT-2006
13:00
Added one small scoop of algae powder
02-NOV-2006
18:00
Added one small scoop of algae powder
03-NOV-2006
22:00
Since the water already appeared quite
clear and the Artemia are growing fast, needing much algae, I decided to add two small scoop of algae powder
this time.
06-NOV-2006
03:00
Added two small scoop of algae powder
22:00
Now that they're bigger (from 2-6mm)
it's a little easier to estimate the number of animals: 100 +50%
08-NOV-2006
22:00
Added one small scoop of algae powder
09-NOV-2006
22:00
Added one small scoop of algae powder and 2
drops of liquid algae
10-NOV-2006
22:00
Added one small scoop of algae powder and 2
drops of liquid algae
Sizes of the Artemia are now about 4-8mm and
all have a dark gut, which means that they feed well. Their color is pale white, which seems to support the
theory that the deep red color of the Artemia from the saline of Cervia/Italy is solely based on the
salt content and not on the species (Artemia parthenogenetica). In my tank with the water of the saline
of Cervia (with high salinity - much higher than the usualy 32g/l salt) the Artemia are still very red
after 70 days in my tank, while the Artemia parthenogenetica from Cervia in one of my regular tanks
with water of about 30g/l salt have either totally lost their red color or at least have lost the red
color partially. Well, there is still the possibility that the red algae Dunaliella and/or the oxygen
content has something to do with the color, but I will investigate this.
11-NOV-2006
22:00
Added 4 drops of liquid algae
12-NOV-2006
18:00
The Artemia seem to develop a slight
red color as they mature. I will closely observe the development in color the next days/weeks.
19:00
Added 3 drops of liquid algae
15-NOV-2006
00:30
Added 1 small scoop of algae powder
17-NOV-2006
00:00
Added 2 small scoop of algae powder -
there are about 50+ more or less adults in the tank now
18-NOV-2006
00:30
Added 1 small scoop of algae powder
20-NOV-2006
18:30
Added 2 small scoop of algae powder
21-NOV-2006
22:30
Moved the airstone from about 10cm water
depth to about 2cm depth, since some adults tend to swim into the bubble chain and are "thrown" to the
surface. The reduction in depth should prevent most such incidences. Furthermore, I spotted many Artemia
which seem to be just about 2 weeks old, also some fresh hatched nauplii. Most females are now mature and have a full
egg sac (brood pouch), so life birthing is underway now.
22-NOV-2006
23:00
I tested the water for
NO2 (nitrite) and the result is surprising. My test showed that the level of nitrite
is <0.3mg/l.
23-NOV-2006
23:30
All Artemia have a really dark, well
actually black gut, which indicates a good feeding and digestion.
Conclusions after 40 days
Constant aeration is essential for nauplius survival (to reach adulthood)
Observations after 40 days
The females matured and started life-birthing within less than 5 weeks
DATE
TIME
24-NOV-2006
01:00
Moved the airstone to about only
1cm under the water surface, since I just spotted one dead adult. The reason for the death might be
constant stream of bubbles where the adult might have passed thru.
24-NOV-2006
19:00
Added 1 small scoop of Spirulina algae powder.
Previously I used the powdered algae from the aquarium shop, but now I'm trying pure Spirulina algae powder.
The seem to feed incredibly well since the beginning since their gut is so dark, actually black.
27-NOV-2006
12:00
Added 2 small scoop of algae powder
29-NOV-2006
19:00
Added 1 small scoop of algae powder -
I'm not sure what happened the past days, but the population decreased. Now only about 30 are left.
Maybe the Spirulina algae powder was not good for them. Another water test for NO2 (nitrite) resulted in
a level of <0.3mg/l.
03-DEC-2006
16:00
Added 2 small scoop of algae powder -
the population is down to <10 animals. I guess either the Spirulina algae powder caused the sudden death
of the rather big population, or some other reason ? Also their guts got very white, usually a bad sign
that they don't feed well. Anyway, it's sad that it ended so soon, but the experiment was successful to
show that high oxygen levels are essential for nauplii to survive their first days/weeks. But as the other
experiments without constant aeration showed, adults can cope with a much lower oxygen level, even without
constant aeration, but only with air intake by adding some water with an aqua leash.
06-DEC-2006
18:00
There are some nauplii visible again :-)
14-DEC-2006
22:30
OFFICIAL END OF THE EXPERIMENT:
There is no single animal swimming.
End of experiment water tests:
Ammonia NH3/NH4: off scale: >>5mg/l
Nitrite NO2: <0.3mg/l
Conclusions after 60 days
Despite the sudden end of the experiment, I have shown that a constant high oxygen level is essential for
nauplius survival. I never had such a huge survival rate in any other tank, which was just "aerated" by
just adding water to replace the evaporated water with the aqua leash.
The Nitrite level is still under 0.3mg/l, which is extremely good. But the Ammonia level is far off scale.
That means that the conversion of Ammonia to Nitrite by bacteria is not working due lack of the Nitrosomonas
bacteria. And of course the conversion of Nitrite to Nitrate by Nitrobacter is lacking too.
So the most likely conclusion is, that due the large amount of dead Artemia during the first days (caused
by the fact that only 10-20% of the nauplii survive) and their decay, the ammonia reached lethal values,
which caused the death of all Artemia.
But I cannot rule out a bacteria or fungal infection.
UPDATE: 27-DEC-2006:
The more and more I think about it, I come to the conclusion that some other effect than ammonia/ammonium
must have been the reason that the culture died. Bacteria or fungal infection is now the most likely
explanation.
UPDATE: 16-DEC-2006:
Bought an pH test kit today: 8.3pH which is very close to the optimum of 8.5-9pH for Artemia.
And the experiment continues: I just added 20 drops of liquid good bacteria (Nitrosomonas and Nitrobacter)
to the bottle. Let's see if those bacteria can change the ammonia/ammonium level to reasonable levels in short
time.
Previously I added 4 drops to a tank with also very high Ammonia/Ammonium levels, but that didn't seem to make
any change. Most likely the Ammonia levels were so high, that the bacteria contained in the 4 drops
couldn't cope with it. Since there are no Artemia in the bottle anymore, I will add liquid bacteria
until there is any change.
UPDATE: 18-DEC-2006:
The Ammonia/Ammonium level is still off scale, but in contrary to the previous test 14-DEC-2006 I noted
the following difference:
Test 14-DEC-2006: When adding chemical #3 to the test solution with the test water and chemical #1 and #2,
the water immediately got dark green with the first drop and when adding the 7th and last drop of chemical
#3, the water was dark green and didn't change.
Test today, 18-DEC-2006: The test solution got just a little yellowish after the 7th drop of chemical #3,
and it needed a total of 3 minutes to get dark green. My conclusion is that the bacteria are already working
hard to convert ammonia/ammonium to nitrite and furthermore to nitrate, but the ammonia level is still so
high that it goes off scale on the chemical test. But it is already much lower than previously, since the
test needed much more time to get dark green.
UPDATE: 20-DEC-2006:
The Ammonia/Ammonium level is still off scale, but it needed longer to get dark green that in the
previous test.
UPDATE: 22-DEC-2006:
The Ammonia/Ammonium level is still off scale. To speed things up and prove that the "liquid bacteria"
can reduce high levels of ammonia/ammonium, I added another 50(!) drops of "liquid bacteria".
UPDATE: 26-DEC-2006:
It seems that it'll take some time for the bacteria to convert the ammonia/ammonium to nitrite and
further. Todays water test for ammonium/ammonia resulted in still off scale levels after some 3-5 minutes.
UPDATE: 28-DEC-2006:
Found in "Artemia Biology. Browne, R.A., P. Sorgeloos and C.N.A. Trotman (Eds), CRC Press":
Artemia can withstand levels of ammonium (NH4) 1000ppm (1000mg/l) and nitrite 320ppm (320mg/l).
Since the regular water test kits don't show such levels - the maximum level they show is
5.0mg/l ammonia/ammonium and 33mg/l nitrite - and therefore I can't determine the actual values
of those chemical compounds. Hence it may take a long time for the good bacteria added in the recent
past to convert the aquatic solution to reasonable levels.
UPDATE: 05-JAN-2007:
Todays water test: Ammonia/Ammonium level: still way off scale.
UPDATE: 25-JAN-2007:
Todays water test: Ammonia/Ammonium level: still way off scale.
After 2 minutes the test showed 2mg/l, after 3 minuntes about 3mg/l and after 4 minutes it went off scale
at 5mg/l.
Conclusions:
The environment must be unfavorable for the bacteria, so that conversion is slow. On 14-DEC-2006 the Ammonia/Ammonium
test immediately got dark green after adding the last drop of chemical #3 and was nontransparent.
Now it takes about 4 minutes to go off scale, but the test is still a little transparent.
The levels can't exceed the lethal values for Artemia (ammonium (NH4) 1000ppm (1000mg/l) and nitrite 320ppm (320mg/l))
since the Ammonia/Ammonium test needs 4 minutes to go off scale at 5mg/l. If it would have 1000mg/l,
Today, Friday, 13th of October(!), I started another test to finally clean up the myths
about aeration. Since the adults I have get enough oxygen by putting just 2 aqua leash
every few days (or even less), the oxygen content of the aquarium water can be fairly
low to maintain acceptable conditions for adults. But in order to provide suitable
conditions for fresh hatched nauplii and to ensure their survival until they mature,
a much higher oxygen level is required. The latter is subject of this test, to prove
that oxygen is the most important factor for nauplii survival and not other parameters,
such as salt quality, salinity and currently unknown parameters.
