Did you know that goldfish have been a staple in households around the world for centuries? They come in a variety of shapes, sizes, and colors, making them a popular pet choice. But what other facts do we know about these beloved fish? Here are 10 fun and interesting facts about goldfish that you may not have known! From their diet to their lifespan, this post will give you an insight into the unique characteristics of goldfish and why they make such great pets. Read on to learn more about these fascinating creatures!

1) Goldfish are the world’s oldest pet.

Goldfish have been kept as pets for centuries. They are the oldest domesticated fish species. In fact, records show that the Chinese kept them in ponds as far back as 1000 A.D.! Today, goldfish are the most popular pet in the world, outnumbering cats and dogs combined. They can live up to 40 years and come in a variety of colors, shapes, and sizes.

2) Goldfish can sleep with their eyes open.

Goldfish can actually sleep while their eyes remain open. This helps them to remain alert and aware of their surroundings. This behavior is actually common in fish, as their primitive eyes don’t have eyelids. Goldfish can also tell the difference between colors, and have been known to recognize and respond to their owners!