What is one similarity that birds share with most fish such as goldfish and angelfish?

One similarity that birds share with most fish like goldfish and angelfish is that they both have scales.

* Birds have scales on their legs. These scales are made of keratin, the same material that makes up our fingernails and hair.

* Fish have scales on their bodies, which are made of bony plates that overlap like shingles.

While the scales may look and function differently, they both serve a similar purpose - protection.