H. H. BOECKAMAZONAS
their fascinating
reproductive behaviors.
Some species will
naturally breed in your display aquarium and you can
just allow some of the young to grow up. If you want
to produce large numbers of juveniles or keep several
species, you need a second tank or a small breeding
setup. Even if you have a single aquarium, you can
modify it to obtain bigger yields. The tank should be
equipped with a three-chamber filter with overflow. After
a few weeks, you can count on finding young fish in the
first filter chamber, but for further rearing you need a
second tank.
If you have two aquariums, you can breed blue-eyes
with the “moving method.” Keep the breeding animals
in a fully equipped aquarium for about two or three
weeks, making sure to offer copious high-quality foods.
After that, move the fish into the second aquarium. The
next morning you may discover the first juvenile on
the surface of the first tank. The young fish must be fed
immediately with the finest food. Using this method,
larger numbers of offspring can be obtained.
An even more convenient strategy is to remove
the spawning substrate from the spawning tank, thus
eliminating the need to move the breeders. Plants that
are bound to wood or stone are suitable as egg substrates.
The substrate is taken out of the tank after two or three
weeks and transferred to another aquarium. You can also
use spawning mops of synthetic wool instead of plants.
The “egg collection method” is also effective. The
eggs are removed daily from the substrate and transferred
into a small container filled with water. It is fun to watch
the eggs develop, but make sure the container is made of
glass or plastic. I use square deli containers that hold half
a pound (250 g). Avoid used containers—buy new ones.
The second important point is the water: you should use
aerated tap water. I once used rain water, but now prefer
reverse osmosis water. If you are afraid that the eggs will
go bad, you can use a fungicide; I use Mycopur from Sera.You can follow the development of the eggs until the
young fish hatch. When the first fry begin to swim on the
surface, they must be transferred into a small aquarium
with a deep spoon and fed immediately.
The timing of the hatch depends on temperature
and when the eggs were laid. Over the next few days,
you will be able to move a few fry daily. But sometimes
the juveniles do not hatch, probably because the egg
membrane is too hard. There are some tricks you can try
to help the larvae. First, I change the water in the bowl.
Pour part of it off and replace it with water from the fry
tank. If the young fish still do not hatch, set the eggs
in motion by blowing air or stirring the water with an
object. If this does not help and the eggs begin to turn
furry, you can spread fine, dry food on the surface of the
water—after a short time, most of the fry will hatch due
to the oxygen consumption.
There is also a method for the lazy fishkeeper who
considers gathering and moving eggs too much work. For
this method you need an overflow or wedge tank. I use a
35-gallon aquarium that measures 32 x 16 x 16 inches
(80 x 40 x 40 cm), divided down the middle by a vertical
glass pane (1) that ends approximately 2 inches (5 cm)
below the rim. The distance to the top should be covered
by a piece of screen or an overflow comb (2). In the right
chamber (B), I install a 1–2-inch (3–5-cm) thick Poret
Foam “Mattenfilter” (3). Behind it, a small airlifter is
installed (4). The outlet pipe (5) is extended so that it
ends in the left chamber (A). Of course, it is also possible
to use other filters, either with an airlifter or a pump, but
the heater can also be hidden behind the wall of foam.
The left chamber is equipped with an egg substrate, such
as a synthetic mop (6), plants, or Sera biofibres.
After a short cycling period, the breeders are placed in
the left chamber. I usually choose a small group of up to
ten animals; the sex ratio should be three males to seven
females. Now you must feed the breeders, but do not give
them live Cyclops, which can endanger the fry later.
After about 10 to 15 days, depending on the species,A. B.
Author’s sketch of overflow
aquarium in operation.