A gold fish scale looks like an onion. This is a good example of how animal structures sometimes resemble plant structures. One of the most dramatic differences between animal and plant cells involves the cell wall: plant cells have a prominent and well defined cell wall whereas animal cells have a barely visible cell wall.

Gold fish are one of the most popular pets. They are a very low maintenance pet and are very inexpensive. They do have a troublesome habbit of dying for no apparent reason though. In fact, it has sometimes been said that gold fish, along with hamsters, are great pets for someone if you want to teach them about death! Gold fish have also been involved in "hazing" and many people have swallowed a gold fish on a dare. In the wild, and in large aquariums, gold fish can live for many years and reach enormous size.