9.2.
It has over-eaten!
The Chaca is swimming
around the tank (without taking cover in the ground as would be its usual daytime
behaviour), and showing occasional signs of retching.
His belly has taken the shape of an extremely large ball it has quite obviously
over-eaten. Im sitting by the tank anxiously after all, two of my Mottled Whiptailed
Banjo catfish (Platystacus cotylephorus) died of over-eating.
However, two hours later it had calmed down and buried itself into the ground again.
It obviously eats if
it gets the chance to do so and then has digestive problems if it was too much and
the food bloats during the digestive process.
I read it here or there
before, but never believed it. Today I found out for myself:
The Chaca chaca
is said to be able to secrete certain substances that lower the pH level to a considerable
extent.
Today, after it had
been quite busy in the aquarium, I had a go at measuring the pH level had dropped
from 7.0 to 5.5! Amazing.....how does it do it and why? I have another two equally
sized tanks with Farlowellas, Rineloricarias and Corydoras seussi connected to the
same water.
Now, lets consider
the following: on the one hand, this is an easy way of lowering the pH level without
having to use alder cones or peat or whatever all Id have to do is stock the
other tanks accordingly. On the other hand, its not a good idea to keep the Malawi
meals in its tank for longer periods of time.
What might this sudden
change of pH (no matter whether up or down) cause? For now, I changed the water
and am back at pH 7. None of the fishes shows any particular reaction.
How and why does a
predatory fish do this? Could it simply be an increased excretion of uric acid caused
by an intensified metabolism? But why is the nitrite level at zero then? What use
is it all to the Chaca, especially with respect to the fact that it doesnt normally
live in pH 5.5 surroundings. Possibly acidifying the environment with a specific
effect on potential prey fish, an acidification which can only briefly be registered
in flowing waters?
What I need to measure
now is the period of time within which the Chaca managed to produce this acidification
all the tanks connected to its circuit contain a total of 360 litres (gross).
11.2.
Two days later the pH level has already dropped to 6.5 from 7 no further intake
of food on the side of the Chaca, it is still digesting.
18.2.
Todays measuring results: kH 2, pH 5.5
Via the Internet I made contact with a Chaca owner who lives in New York and spends
a lot of his holidays in Bangladesh where his parents come from. Thats where he
hears some stories about the Chaca. They say that it is supposed to be able to secrete
poison, for example. He himself has been keeping a Chaca bakanensis for quite some
time now and is able to confirm the decrease in pH which he compensates for with
baking soda. His attention had been drawn to this particular ability of the Chaca
- which, to my knowledge, has been described nowhere else up to now - by the fact
that a feeder goldfish which had only just been put into the Chacas tank died within
seconds. He thereupon examined the water values.
The Chaca does not
produce any solid metabolic end products; it digests everything very thoroughly
and excretes fluids only, but what kind of fluids they are!
Water values compared to Chaca water | |||||
My tap water:
(always) |
gH 16 |
kH 10 |
pH 7,5 |
|
|
Normal aquariums:
(after a change of water) |
gH 14 |
kH 4 |
pH 7 |
|
|
Chaca aquarium:
(7 days after a change of water) |
gH 11 |
kH 2 |
pH 6 - 5,5 |
|
|
Acidification
of the water (approx. 300 litres in 7 days) | |||||
Datum |
pH |
kH |
|
|
|
11.2. |
7.0 |
4 |
|
|
|
12.2. |
6.5 |
3 |
|
|
|
13.2. |
6.3 |
3 |
|
|
|
14.2. |
6.0 |
2 |
|
|
|
18.2. |
5.5 |
2 |
|
|
|
For a more precise
analysis I sent a sample of the water from the Chaca tank to a laboratory and received
the following measured values: | |||||
pH: |
4,26 (!) |
|
|
|
|
LF: |
731 µS/cm |
|
|
|
|
GH: |
12,6°dH |
|
|
|
|
KH (SBV) |
no traces (!) |
|
|
|
|
NH4: |
0,44 mg/L |
|
|
|
|
PO4: |
11,3 mg/L |
|
|
|
|
Fe: |
0,267 mg/L |
|
|
|
|
Cu: |
0,214 mg/L |
|
|
|
|
CSB: |
218 (!) mg/L |
|
|
|
|
TOC (Total Organic Carbon)
(Im LW ist der bei <3 ppm) |
89.5 ppm (in tap water TOC is at
<3 ppm) |
|
|
|
|
To rule out any doubts:
Among my 12 aquariums
Ive got two towers of three aquariums in the cellar, the water circuits of which
each run via a fourth filter tank.
To the left then, there
are three tanks with Rineloricaria and Farlowella offspring at 26° C in tap
water (see values shown above).
To the right there
are also three tanks with Hemiloricaria and Farlowella offspring and one Chaca chaca
in the bottom tank plus a P. gibbiceps of 15 cm and a few feeder fishes (Tilapia,
5 cm) from time to time.
The water values on
the left-hand side are stable, but those on the right-hand side have been fluctuating
within seven days as stated in the above shown table since I got the Chaca.
I believe that other
factors apart from the Chaca chacas digestion can be ruled out, and I have the
confirmation of the phenomenon by another Chaca-keeper.
Otherwise the Chaca
requires very little attention or care. It lets me transfer it from one tank to
another by hand without showing any resistance even a phlegmatic banjo catfish
wriggles around more than that! And concerning all those tiny little teeth in the
top and bottom row of its large mouth: they sure look dangerous, but theyre only
little bits of skin!