Due to concerns over certain species' status in the wild, these restaurants will also take Chilean sea bass (Dissostichus eleginoides), orange roughy (Hoplostethus atlanticus) and shark (Class Chondrichthyes, Subclass Elasmobranchi (part)) off their menus.
Sharks are not fish, but elasmobranchs of the class Chondrichthyes. They are marine animals with cartilaginous skeletons and respiratory gills, similar in morphology to that of the fish, although many sharks are viviparous and copulate.