Just to let folk know, I've given up on this idea. I've had a mixed response and decided that its beyond me. For anyone who is interested, here's some information that swayed me towards a huge "no chance".
There are several falacies with the idea of high density apisto keeping:
1. Uwe Römer's studies were conducted primarily during the dry season when
many streams are drying out and all that are left are isolated pools filled
with damp leaves and little water. These are refuges for fish, someplace to
survive until better conditions arrive.
2. Food becomes scarce during the dry season, so fish are not in optimal
condition for breeding. The drying habitats definitely are not ideal
breeding environments.
3. The drying habitats definitely are not ideal breeding environments. As
such, almost no breeding occurs during the dry season and very few adult
fish survive this period. The dense populations of fish are only interested
in surviving, not in defending breeding territories. Little energy is
expended in territorial aggression. Apistos, like most small fish in the
Amazon, breed seasonally during the rainy season when water spreads out into
the surrounding 'flooded forest'. Now the area for suitable breeding
territories has not only increased by orders of magnitude, but food species
(insects & aquatic crustaceans) have exploded in numbers, and water quality
is improved markedly. The surviving young explode in size & maturity and are
ready to breed. Now they become territorial, but because the area available
for territories has increased, their population density has dropped
drasticly and territorial aggression probably is not very high.
Now, for David Soare's suggestion for high density keeping of apistos. It
works well if:
1. The fish are not sexually mature - as you would find in grow-out tanks.
2. There are enough breeding territories that are hidden from sight of
surrounding territories. For example, an aquarium filled almost to the top
with jumbled piles of PVC pipe or loose layers of leaf litter.
Even in such aquariums, sexually mature fish will want to breed (assuming
that the water quality is adequate) and these dense populations will lead to
levels of aggression that rarely occur in the wild. Mature fish will be
killed and fry mortality will also be high. The quantity of surviving fry
will be much higher in an artifical breeding situation where the male is
removed when the eggs/fry appear, and the female is removed once the fry
start to wander away from their mother. To prove this take 20 pairs of fish
from the same spawn of an 'easy to breed' apisto. Spawn 10 pairs
artificially in 10 smaller tanks. Take the other 10 pairs and put them in a
tank about 2x the volume of the others. After a year compare the number of
fry & the numbers of adult losses. You'll see which is more productive (and
actually more 'natural').
Anyway, thanks for showing an interest people. The input was appreciated!
Mark
/www.lem.net/alf/css-index-eng.htm Alf Sthalsberg has dealt with some Apistos in his time and is quite a respected guy in the cichlid secene and from what I have heard is open to being contacted with questions. Might be worth sending him an email about it?
