1. What a bunch of carp!
The two favoured denizens of the garden pond are goldfish and koi, and both are types of ornamental carp. They are from the family Cyprinidae and for you scientific-name purists, koi is scientifically named Cyprinus carpio, a subspecies that will revert to its original colour in a generation or two if allowed to breed as they like. Goldfish are Carassius auratus auratus and are the most modified species we know of as they have been bred for thousands of years.
2. A tale of two tails.
Goldfish have been bred into two distinct types: single-tail and double-tail. The doubles are languidly lovely, but they are slow so be careful not to mix them with the faster single-tailed varieties or they will never get enough to eat, being out-competed by their fast cousins when the dinner bell rings. Among the double tails are the big, googly-eye types that look bizarrely grotesque. Single-tails are most suitable for ponds and can get along with koi.
3. Old man koi.
Koi fish can live to incredible ages. The oldest one ever recorded was named Hanako from Japan. Hanako is said to have lived to be 225 years old. Most live to be about 60 to 70 years, though, if they are properly raised and cared for. Goldfish on the other hand have an average lifespan of 10 to 15 years, although a happy goldfish can easily reach 30.
4. Is it a koi or a goldfish?
Aside from being of differing shapes (many goldfish are shorter and more rotund than koi), goldfish are the smaller of the two when allowed to grow to full size. There is also more variety in fins and tails. Koi, on the other hand, exhibit more patterns. Koi also have a split caudal (tail) fin. On the goldfish, the dorsal (back) fin is concave, while the koi dorsal fin is convex.
5. Hey! I know you…
Both these ornamental carps have very good memories. They can remember their owners and will come out to interact with those they know and feel comfortable with. They can get depressed and sick when their favourite humans leave for an extended period.
6. A goldfish never forgets.
It has been shown that goldfish can remember what they learned up to a year later. In an experiment, goldfish were taught to respond to a certain sound, which called them at feeding time. They were then released into the wild, and six months later, the sound was played on a loudspeaker. The now-free goldfish gathered at the place where they had been released.
7. Smart koi.
Koi are just as smart or maybe even smarter than goldfish. They can recognize their name and will pay attention if overhearing it when a separate conversation is taking place. They have been taught to play all sorts of games like basketball and soccer.
8. I see you.
Both fish have excellent eyesight, recognizing the colours red, green, blue and ultraviolet. They also recognize humans and will hide when strangers come near. They like to be petted and will kiss and rub against friendly hands in their pond or aquarium. One group of koi was taught to take food from a baby bottle. Click the image to watch the YouTube video.
9. Good daddy.
Male koi take part in raising the fry (at least the ones they don’t eat) and will discipline them and protect them from predators such as herons. While koi are released from eggs, the male does his part by chasing and then bumping against the female to get her to drop her eggs.
10. Losing their colour?
Colour loss in koi can be a sign of breeding, illness or stress. It can happen if their nutrition is deficient, the water’s oxygen is low or when the water is too warm. They are brightest when cooler. They may also be drained of colour when they encounter a heron, raccoon or a duck, which will eat the babies. On the other hand, large ornamental carp will turn tit-for-tat and also eat unsuspecting ducklings.
– Dorothy Dobbie Copyright©
Pegasus Publications Inc.