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

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

* Birds have scales on their legs, which are actually modified feathers. These scales help to protect their legs and provide grip on surfaces.

* Fish, on the other hand, have scales covering their entire body, which helps them to move through water more easily and protects them from predators.

While they might look different and serve different functions, both scales are made of the same type of material – keratin.