Bass is a name shared by many perciform fish commonly pursued for sport and sometimes eaten as well. The perciformes are bony fish which resemble perch, and often have spines along their fins. Bass can be found in both fresh and salt water, and their preferences vary from warm to temperate. Bass are popular for sport fishing because they tend to fight the fisherman more than some species, making bass fishing a challenging activity.

The moronidae are temperate bass species, and can be found in rivers and estuaries. The most famous member of this group is the striped bass, one of the most popular sport fish of all time. Temperate bass have spines directly behind their gills, two dorsal fins, and a forked caudal or rear fin. The temperate bass species can reach 70 inches (180 centimeters) in length, and are commercially fished in some parts of the world.

Temperate bass tend to be highly migratory, and will sometimes travel great distances. All of them spawn in fresh water during the springtime, and feed on smaller fish species along with shrimp and other crustaceans. Some temperate bass are commercially farmed as well, and fishermen can take advantage of farmed stock, frequently introducing it to depleted waterways.

The centrarchidae are warm water bass species, and are sometimes known as sunfish, perch, or bream. They are exclusively native to North America, and frequently found in rivers and streams along the Eastern portion of the United States. These bass are characterized by multiple rayed fins and spines, which can be painful to unsuspecting fishermen.

The most famous among the warm water bass species is the largemouth bass, so called because its mouth extends well back behind the eyes, allowing it to eat very large foods. Largemouth bass are a muddy green in color, and enjoy lurking in vegetation or in artificial pilings for their prey.

Many bass are sport fished, which means that after being caught they are released, although some species are eaten. Many areas have restrictions on the type and size of fish that may be caught, and fishermen should familiarize themselves with these regulations before embarking on fishing adventures. Bass is a heavily managed species, and does not appear to be at risk thanks to careful maintenance of fish stocks.

Some species such as Chilean sea bass are given the common name bass, although they are not in fact in the perciform family. Most of these species share the characteristic dense white flesh with minimal oils, and borrow the bass name for marketability.