Molecular and morphological evidence for the widespread distribution of Laticola paralatesi infecting wild and farmed Lates calcarifer in Australia.

Infections with monogeneans of the Diplectanidae can limit productivity of and cause considerable health issues for fish in aquaculture. To date, 9 species of diplectanids have been reported from the Asian sea bass or barramundi Lates calcarifer (Perciformes: Latidae) in the Asia-Pacific region. This study characterised the diplectanid parasite fauna found infecting wild and farmed barramundi from 5 localities in tropical Australia, including north Queensland and Western Australia. A combination of morphometric and comparative genetic analyses of partial 28S ribosomal RNA (28S rRNA) from specimens recovered were used to confirm their identity and to explore relationships with other diplectanids. These data revealed that a single, dominant species of diplectanid, Laticola paralatesi, infects wild and farmed Lates calcarifer in tropical Australia. Laticola lingaoensis Yang, Kritsky, Sun, Jiangying, Shi & Agrawal, 2006 is synonymised with L. seabassi (Wu, Li, Zhu & Xie, 2005) Domingues & Boeger, 2008 based on the combination of the host infected (Lates calcarifer), geographic distribution, distinct morphological similarity, and identical 28S rRNA sequence data identified here. Laticola seabassi is now designated as the type species of Laticola due to nomenclatural priority.