There are lots of fish called bass. It is just a generic common name given to fish who look "bass-like", the same is true for the name perch. There are some families of basses such as the Sea Bass (Serranidae) and the Temperate Bass (Moronidae). These are what would be considered "true bass" if you want to get picky. The Moronidae family is often called the true bass family.
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