Names: Guppy, Millions Fish
Name: Poecilia reticulata
Discovered: Known under its current scientific name
since 1963, but was originally scientifically described in 1859 by
distribution: This fish is originally South America, including
northern Brazil, Venezuela, Barbados and Trinidad. However, feral
populations occur in many parts of the world. Some of these are from
introductions to try control mosquito populations; unfortunately,
they had little or no effect on the mosquitos, and sometimes a negative
effect on native fish populations. Feral populations have been reported
in Africa, Australia and Singapore.
Habitat: This fish occurs in a massive variety of
habitats, from mountain streams to brackish river tributaries.
Sexing: Guppies can be sexed from about 4-5 weeks. The males have a modified
anal fin, this is called the gonopodium.
Setup: Guppies are a very popular aquarium fish, and don’t
require anything special. They are perfectly at home in a peaceful
community aquarium. At least 2 females should be kept to each male,
so they aren’t continually harassed. Also for the same reason,
a tank housing both male and female guppies would ideally contain
plants so the females can get out of the way of the mal. Although
water chemistry is not critical for these fish, they prefer slightly
acidic water. Salt is optional, only some, not all wild guppies live
in brackish conditions.
Size: Males grow up to 3cm and females up to 5cm,
although captive species may grow larger.
Temperature: The ideal temperature for this fish is 21 – 28°C.
Breeding: This fish is amongst the easiest to breed, in fact, it can
be difficult to stop them! The females are nearly always pregnant,
and can store sperm for up to 6 months. She will also give birth to
between 10 and 40 fry every 4 to 6 weeks.
One of the best methods for getting plenty of healthy strong fry is
to set up a breeding tank. A 10 Gallon tank is easily large enough,
with plenty of plants for fry to hide in, such as Java Fern or Java
Moss. Many people use breeding traps or nets in their community tanks.
These are small plastic or net containers that float in the tank.
These can easily stress adult fish, and lead to aborted pregnancies
or even death. If you must use them, please only put the female in
just before she is due to give birth, or even better, wait until the
fry have been born and then catch and add them the trap. If you are
using a plastic trap, then remember to change the water in it regularly.
of the fry: Guppy fry are easy to raise. At least a couple
per brood would probably survive in a planted community tank. But
if you want to save more of them, then you could use a separate “growing
on” tank. A bare 10 gallon tank again would be enough. Just
use an air powered sponge filter so the fry don’t get sucked
in. You can feed them a variety of things such as liquifry for the
first couple of days, then move up to fine crushed flake foods. Baby
brine shrimp would also be a welcome addition. Remember to keep these
tanks very clean as fry are more susceptible to pollutants than adult
fish, so a small water change every day will be necessary, and also
remove any faeces or dead fry.
Extra Notes: These fish are undoubtedly one of the
most popular in the aquaria hobby. They come in a massive variety
of spectacularly coloured strains. Many fish or pet stores recommend
these fish as suitable for first time fish owners. They are easy to
look after, but will usually struggle with a cycling tank, and would
probably die, so they should not be added to a tank until the cycle
has been completed.