Herbivorous fish play a key role in maintaining healthy ecosystems, especially in tropical reefs, where they promote a balance between corals and macroalgae. Herbivorous fish include Acanthurus lineatus or lined surgeonfish (also known as blue-banded surgeonfish, blue-lined surgeonfish, clown surgeonfish, pajama tang, striped surgeonfish, and zebra surgeonfish), Acanthurus nigrofuscus known as the Lavender Tang, Brown Tang, or Spot-Cheeked Surgeonfish, and Zebrasoma scopas known as the brown tang, two-tone tang, scopas tang or brush-tail tang.[4] The unicornfishes (Nasinae) genus is primarily herbivorous. Most of the nearly 100 species of the parrotfish family are herbivores.[5][6]