Page 330 - Encyclopedia of Aquarium and Pond Fish, 3rd Edition

328 POND FISH: BREEDING

Breeding

Left to their own devices, a number of coldwater fish will
breed readily in a pond environment. However, in a densely
planted pond, a successful spawning may go unnoticed
until later in the year, when the fry are larger and can
be seen feeding alongside the adults. Breeders who
like to have more control over the reproductive
Koi breeding is a bit of a
habits of their fish often spawn them artificially. lottery, since there is no guarantee
that the coloration and patterning of the
fish—even with top-quality specimens—will be
When egg-scatterers, such as goldfish and koi, are kept in a transferred to any of the offspring.
group, they may come into breeding condition simultaneously
and spawn together. In such cases, having more males in the be introduced to the pond in cold weather—the shock of the
group than females will ensure that a higher proportion of the cooler pond water may kill them. If necessary, keep them inside
eggs are fertilized. If you want to breed particular fish together until the following spring, when conditions will be warmer.
and be sure of the parentage of the fry, you should keep your
chosen breeding stock on their own. It is also a good idea to Hand-stripping
set up a special spawning pond for them so that you can move Some breeders of goldfish and koi prefer not to allow their fish
the adults back to the main pond after the eggs have been laid to spawn naturally. Instead, a male and female fish are given an
and rear the young on their own. After spawning, the adults injection of pituitary gland extract to bring them into breeding
may be exhausted and float on their sides at the surface. They condition. Hand-stripping (massaging the underparts of the
will soon recover, but make sure they have not sustained any fish) is then used to expel eggs from the female and semen from
fin damage during spawning, which could lead to infection. the male. The eggs and sperm are placed together in a mixture
If you choose to hatch and rear the fry in a tank, either of urea and iodine-free table salt called Woynárovich’s solution,
outside or indoors, use a mature sponge filter to provide gentle which aids fertilization by removing the eggs’ sticky coating.
filtration. Feed the fry on infusoria (see pp.67–68) at first, or a Finally, the eggs are washed in a tannic-acid solution to protect
commercial substitute, and then wean them onto powdered them against fungus and left in an indoor tank to hatch. With
flake. Add them to the pond when they are about 1 in (2.5 cm) hand-stripping, up to 90 percent of the eggs are fertilized,
long and too large to be eaten. Fish reared indoors should not compared with 50 percent when the fish spawn naturally.

BREEDING GOLDFISH Breeding brush traps eggs and
protects them from being eaten
Goldfish, like many other egg-scatterers, can be
Plant material pulled
persuaded to spawn onto an artificial medium out with the brush
such as a breeding brush or a spawning mop,
which is then transferred elsewhere so that the
eggs can hatch in safety. The adults should
spawn again within a few weeks, particularly if
they are kept well fed on nutritious live foods
such as bloodworm.
1
2
Spawning mops are 1 Place the breeding brush in the pond 2 Transfer the brush to an indoor tank
smaller than breeding Make sure there is enough clearance for When the fish have spawned, move the
brushes and more the fish to swim over the brush and spawn. brush to the hatching tank without delay.
suitable for aquariums Egg-laying usually occurs as the sun starts to Keep it submerged in dechlorinated water,
than ponds. warm the water in the early morning. to ensure that the eggs do not dry out.

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