Fun fact – they are one of the easiest kinds of Carassius auratus fish to breed!
Of course, it’s still tricky business, but they can be helped along by giving them yummy treats like frozen blood worms or brine shrimp.
And when they do…
You’d better be prepared for a LOT of babies! (Goldfish can have over 1,000 at a time.)
This is How the Fantail Got its Tail!
All goldfish used to be slim-bodied fish like the Common – with one tail and one anal fin.
So how did this fish end up with 2 of each?
Goldfish fins of non-fancies are actually made of a double-layer. But during the Ming Dynasty 600 years ago, a strange genetic mutation appeared…
The double layer of their tail fin and anal fin started to split apart and grow separately!
Betcha didn’t know that one ;)
Early Fantail goldfish probably looked a lot like the Watonai variety before they were bred to have shorter bodies…
3 Surefire Ways to Know if Your Fish is Actually A Fantail
So, how do you know if your fish is one of these kinds of fish – and not some other breed?
1. Egg shaped body
Fantails fall into the category of “Fancy Goldfish,” which are known for their round, short bodies much deeper than their slim-bodied brothers.
They were bred to be this way to look nice.
But here’s the catch:
This actually gives their organs less space than their ancestors had, making them prone to swim bladder problems from their diet.
(More on that in a minute.)
2. Double tail fins
Goldies like the Common (those little guys sold in bulk as feeders in pet stores) have one straight tail fin with 2 lobes on the top and bottom.
Not this fish!
They have 2 tails in one, split down the middle. This gives them 4 separate lobes… unless your fish is has a fused tail – lovingly known as “tripod.”
Quality specimens will have a good split down to the base of their tail.
3. Double anal fins
Granted, not all of these fish have them , but double anal fins are another clue that your fish is one.
(Anal fins are the fins closest to the tail underneath the fish).
4. No other fancy features
This breed is the “plain Jane” of the fancy fish category without all the showy characteristics other breeds have.
And this is exactly why some people love them – they like that down-to-earth look!
How to Take Care of Your Fish Properly
This might surprise you:
But Fantail goldfish are actually one of the best beginner fish.
Because they are so hardy, they are much more likely to survive any mistakes new pet fish owners will probably make.
You will also want to make sure you have the equipment needed to take proper care of your pet.
Which brings us to the first point…