There is a popular belief that Guppies are a hardy fish which can be
neglected, yet still flourish, and that they are a fish for the
beginner.
Now although many fishkeepers started with Guppies,
over the years the species has encountered some quite bad press, mainly
due to overbreeding and inbreeding issues.
However, there is
absolutely no reason why you cannot have a perfectly healthy tank of
these stunningly coloured fish. As Guppies are easy breeders, with a
little care you can optimise your chances for a healthy, vibrant stock.
Getting down to basics
A
breeding set-up should be designed for easy maintenance, especially as
chances are you'll end up with loads of tanks! I keep my breeding tanks
in the bare mode, so no plants or gravel.
Small tanks will
suffice: 25 l./5.5 gal. for a breeding trio and 36-45 l./8-10 gal. tanks
for growing on. As a rule of thumb, allow 2.5cm/1" of fish per gallon
to allow your fish to achieve their full potential.
Some
enthusiasts opt for higher stocking levels, which is fine if you carry
out more frequent water changes. Don't push your luck as you could end
up with stunted, poor quality fish.
As for filtration, I opt for
air-driven corner filters or sponge filters with plenty of airflow. And I
mean plenty, such that the water above the filter looks like it is
boiling.
Such a strong flow serves one purpose; it forces the
fish to develop strong muscles, especially in the caudal peduncle. This
helps the delta varieties hold their tails in a more natural way and not
look like the tail is too heavy, making the fish looks somewhat bent.
Ideal
water parameters are pH 7.2 (normal range 6.8-7.8); 8-12 degrees GH
(normal range 4-20 degrees GH); and a temperature for fry of 25.5
degrees C/78 degrees F; juveniles (four to eight months) of 24.5 degrees
C/76 degrees F, and adults somewhat cooler at 23.5 degrees C/74 degrees
F (normal range 10-29 degrees C/50-85 degrees F).
A Guppy needs
12 hours of lighting each day, best provided using 30-40W fluorescents
mounted above your tanks. Don't be misguided into thinking that
intensity matters.
Duration is far more important, and a simple timer will ensure that the lights are turned on and off at the right time.
Care and maintenance
Guppies
are omnivores, so offer as wide a range of quality flake food, live and
frozen foods as possible. It is also better to feed small amounts every
few hours than one gigantic feed.
Frozen and live food are
digested easier than flake food, so can be fed in larger portions. As a
guide, if your fish do not eat all the food you put in the tank in two
minutes, chances are you're overfeeding them - or they could be ill.
If
you overfeed your Guppies, the excess food passes through the gut
without being properly digested and will foul the tank. Try to avoid
feeding a diet rich in protein as this can cause constipation, causing a
build-up of toxins in the fish's gut.
Which leads me to the
point that fish create waste, and this waste creates both good and bad
bacteria. If waste builds up within the tank, eventually the bad
bacteria will outnumber the good and the water conditions start to fail.
Correspondingly, your Guppies' fins and health will
deteriorate. Regular water changes are a must. I carry out weekly
changes of 25%.
Know your strain
Before you attempt to breed Guppies, you need to understand the characteristics of your chosen strain - each is unique.
This
can be tricky if the person you bought your fish from does not know its
genetic make-up. However, all is not lost as close observation and the
keeping of breeding logs will reveal much.
The first step is to
note all the characteristics of your stock. For instance, does the
colour have a uniform look or is it more intense in specific areas? What
about fin shapes? Find out what the ideal shape should be.
Fellow
enthusiasts are always a good source of information. Find out if your
strain carries the traits you want on the X- or the Y-chromosome. The
Internet can be very useful in helping you trace the genetic make-up of
your fish.
Obviously if you have a specific goal, eg. solid black
fish, this makes it easier to organise your tank space and select the
fish you intend to keep out of each litter, ie. as much black in the
body, or even a particular dorsal or caudal shape.
Never, ever
keep just the one pair of breeders: disease happens, no matter how
careful you are, and you do not want to put those years of hard work in
jeopardy by losing just two fish. Ideally, aim for two or three trios in
separate tanks.
Keep those records
Your breeding log should have the following information:
Identity: Give
each breeding pair or trio an identity number, so your first pair is
number 1, your second number 2 and so on. This allows you to trace the
lineage and any crosses that have been made.
Sex: M or F for male or female.
Colour/strain: eg. half-black red delta or yellow snakeskin.
Generation: Start with P for parentage, followed by F1, F2 etc.
Cross:
Are the fish being bred brother to sister (siblings), parents to
daughter or son (backcross), or to a genetically related strain
(outcross)?
Parents: What was the identity number of the parent fish?
DOB: Date
litter was dropped. This is useful to work out the age of fish for
breeding and to track their progress for finnage and colour development,
which varies according to strain.
Breeders produced: Did they produce any litters with potential breeders?
Notes: Allow plenty of room for observations about when the fish started to sex out, ratio of males to females, growth rates, etc.
Always
mark the tank with the ID number and the date the litter was born.
Masking tape is good as you can easily remove this and attach it to the
fish's new tank if you move it.
Line breeding
The
problem with successive inbreeding is that each generation loses some
genetic diversity. Line breeding helps overcome this and keeps a strain
true.
Basically it combines inbreeding with a crossing from a related line every few generations, ensuring healthy Guppies for years.
The
most common method is to break your strain into two lines for
inbreeding. Then after three generations, cross the lines. A simple
illustration of inbreeding is:
Line 1 Line 2
P1 M F P1 M F
F1 M F F1 M F
F2 M F F2 M F
Cross Line 1 F2 female (F) with Line 2 F2 male (M), and Line 2 F2 F with Line 1 F2 M.
Guppies
are typically four months old before they can be bred, so to repeat the
above for three generations would take about 12 months before your
first cross. Also the more lines you run, the more diversified your gene
pool will be.
Out-crossing
This refers
to the mating of two unrelated Guppies. While inbreeding reduces the
variations of your offspring and line breeding helps keep your gene pool
intact, out-crossing corrects or adds a gene to your strain.
For
example, you may want to get a bigger dorsal fin, improve the colour or
rectify a defect in the caudal fin. Or you may even want to create a
totally new strain.
Having said that, out-crossing is best not
attempted by a novice for if you get it wrong, you could lose the strain
traits altogether.
With out-crossing, it's critical to ensure
strains are compatible - some colour strains mix, others don't. For
instance, crossing a variegated snakeskin with a half-black red results
in a very mixed-up Guppy. You really need to keep the original strains
pure.
Out-crossing demands plenty of tank space and patience to
carry out the required backcrosses to end up with the results you want.
You'll need to use established strains whose genetics are stable,
meaning that all offspring look identical.
Finally, try the
cross both ways - female to outcross strain and male to outcross strain;
you may not know whether the trait you want is X- or Y-chromosome
linked.
Backcrossing
This is where you breed,
say, the male of a strain that you want to rectify a problem back to
one of his daughters from the outcross, or the female of the strain back
to her son from the outcross.
The aim is to restore the strain to its original format, but with the trait fixed.
You
may have to perform this a few times. The way to check is if the
sibling-to-sibling mating produces replicas of the parents with the
trait fixed.