How to breed fantail goldfish


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Ray Rich took up the gauntlet to breed goldfish and describes his success with the fantail variety.

They may be one of our more basic fancy varieties, but fantails have a simple, sturdy charm. Strangely, although hardly the most highly-developed fancy, they can be very challenging to successfully and consistently breed.

Goldfish are easily tough enough to survive our winters, responding quickly as soon as spring arrives. With the arrival of warmer weather, the males start charging about and looking for something to breed with!

Good English fantails should have strong, stiffly held split tail fins, showing a deep fork and a good fan shape when they are viewed from above.

The top lobe of the tail should not droop below the horizontal. Fin extremities should look even and rounded. Some enthusiasts prefer the shorter finnage and some a slightly longer style of fins.

The body should be deep and evenly rounded with no bumps, especially behind the head. As with all fancy goldfish, females tend to have deeper bodies.

The colour in calico fish should be a deep base blue background with patches of red, orange, yellow, brown and black. Colour should extend into the finnage.

Many breeders prefer black spotting over the body and black stripes in the finnage.

The metallic effect fish should have a very deep colour, like polished metal. The deeper and more brilliant the better.

All of these 'shoulds' are fine in theory, but achieving them and successfully breeding year after year is an entirely different matter! Most breeders have to try hard to keep depth of body and maintaining a good blue background colour can keep you up at night.

Partner choice

Breeding fantails is very time consuming! Just choosing the right males and females can take great thought and often many test spawnings. Just spawning the best two fish you have doesn’t guarantee good results.

Two fish with good colour often produce offspring with dull coloration and the same can be said for finnage. I find that breeding a light-coloured, short-finned fish with a dark-coloured long finned partner can sometimes be the answer.

However, there’s no absolute solution and that’s why I tend to do small test spawnings first.

Breeding regime

I would normally start my breeding programme in early spring, around March 1, and often warm the water to about 17°C/63°F. Then I try to spawn one female with three males just to spread my bets. The chosen female is usually two years old, while the males can be only half that age.

My spawning tank is 91 x 61cm/3’ x 2’ and I use lots of Hornwort as the spawning medium. I normally let the female settle for a couple of days first and introduce the males early one evening in the hope of a spawning the following morning.

If successful I normally let the fish spawn all day and take them out for a rest and good feed that evening. After spawning, and when the adults are removed, I turn the thermostat to about 22°C/72°F, sit back and wait.

Fertility rate

In reality, after about 24 hours I end up counting the unfertilised white eggs to check fertility rate! It’s so easy to see so many white furry, fungus covered eggs that you expect only a few fertilised ones — but normally a surprisingly good hatch follows in three to four days.

Those tiny fish stick to any available surface, each having a little food sac attached which they absorb after 24-36 hours. Then they head for the surface to gulp air to inflate their swimbladder and they’re off, darting everywhere.

Now your work really starts! They now need food, heat, light and clean water, but, of these, their most important requirement is clean water. They can tolerate being fed very little, cool water and dark surroundings — but certainly not dirty water.

After hatching I normally wait some 36 hours to let the babies absorb their sacs and then feed them daily on newly hatched brineshrimp. I maintain this for the first six days then move them to a clean tank. From then on, until ten weeks old, I move them to new, clean quarters every three days.

Normally about two weeks after hatching, and while moving the youngsters to clean quarters, I begin to identify and select fish with divided tails.

Shadow check

Everyone has their own method, but I wait for a sunny evening and then, looking from above, examine the shadow thrown by the fish’s tail, as that normally reveals if it is properly divided.

If breeding nacreous (speckled) fish any metallics will not normally colour up. They just look dark green and shiny and any matts (white-ish) will not be needed. They just remain pink.

I continually select the best fish, looking for a good deep body, double anal fins, dark, interesting colours and stiffly held finnage for the next eight weeks or so.

Their menu moves on to bloodworm at around four weeks and then gradually to my own home-made food from around seven to eight weeks.

Hopefully by the end of this process you should have some very fine young fantails! However, breeding often takes quite a few attempts before you get confident about things — so be patient as well as persistent.

Eight common fantail faults

  • Tails too long and dropping down. Often finnage gets longer as the fish grows — so if a young one already has long finnage it will be even more pronounced in adulthood.
  • Tail too narrow when viewed from above. This is not a good fan shape.
  • Signs of a hood developing on the head. Top of the head looking like a Ranchu or Oranda.
  • End of fins too pointed.
  • Bump at the back of the head. Not an even contour from the nose to the dorsal fin.
  • Poor colour. Too little blue and a predominance of orange or red.
  • Body not deep enough.
  • Fish not swimming in an even fashion in the water, either head up or down.

Did you know?

Goldfish (Carassius auratus auratus) were one of the earliest fish to be domesticated.

They were domesticated from the wild fish, a dark greyish brown carp native to Asia, and first bred for colour in China more than 1,000 years ago.

Find out more

The Goldfish Society of Great Britain encourages the study of all characteristics of goldfish.

Members breed and distribute varieties, show and exhibit them, and a bulletin is published regularly.

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