No, bichir are generally not considered to be aggressive fish. They may show some aggression when they feel threatened or if there is a hierarchy in the tank, but these behaviors are rare and should not be cause for alarm. In general, bichirs tend to be peaceful with other fish and can peacefully coexist if given enough space. Bichirs have been known to eat smaller fish however so it is important that any tankmates being introduced into the same environment as them must match their size and temperament. Depending on species selection and water parameters, bichirs can also get along with catfish, corydoras, plecos, larger tetras, livebearers (such as guppies), rasboras , loaches , angelfish , silver dollars , and gars .