Maccullochella is a genus of large Australian predatory freshwater fish within the Percichthyidae family. The Maccullochella genus was named after an early Australian fish researcher with the surname McCulloch.The Maccullochella species are called 'cod' in the vernacular.At the time of European settlement of Australia, members of the Maccullochella genus dominated the Murray-Darling river system (Murray cod, M. peelii, and trout cod, M.