The Goldfish (Carassius auratus)
Recently, in the news, reports have popped up showing what is allegedly a 9-pound goldfish. While goldfish may be able to grow up to 9 pounds, it is certainly not likely to happen. Some experts actually believe that this fish was a small koi. Either way, despite being great house pets, goldfish are fascinating animals that have a lot that we can learn about.
Physical Description and Behavior
Describing a goldfish can be hard because there are many breeds of them that can vary in size, shape, fin location, and even the colors that they sport (yeah, some goldfish can not be gold at all! It is possible for them to be white, red, brown, and even black.) The largest goldfish on record seems to have been about 5 pounds, but they are generally far smaller, weighing about half a pound. They can also live upwards of 41 years, which is fascinating to consider.
Fun Fact: Wild goldfish are not the beautiful orange color that you would think, but are actually grayer with a tint of gold. Their wild vivid colors and odd shapes are a result of over a thousand years of breeding.
Goldfish, despite how they look, actually have pretty high cognitive abilities. They can distinguish between humans and even choose favorites between their humans and humans they do not know. They can even be trained to react to light signals of different colors, such as being able to be trained to go through hoops. Sometimes, they can even travel to the top of the tank, "begging" for food.
Habitat and Location
These fish are freshwater fish, but they have been found in more brackish water before. They have been introduced all over the world and can be found from the US and Canada all the way south to Argentina. As well as all of Europe, Australia, New Zealand, all throughout Asia, Russia, the Middle East, and even South Africa.
They are considered to be of Least Concern according to the IUCN Red List.
You can find out more information, including information on a lot of the different breeds here: