Shirakashi, S., Tsunemoto, K., Webber. C., Rough. K., Ellis. D. and Ogawa (2013). Two Species of Cardicola (Trematoda: Aporocotylidae) Found in Southern Bluefin Tuna Thunnus maccoyii Ranched in South Australia. Fish Pathology. 48, 1-4.
We determined the species of an Aporocotylid blood fluke found in the gills of Southern bluefin tuna Thunnus maccoyii ranched in Australia. Both morphological and molecular data indicate that the parasite is Cardicola orientalis, reported previously only from Pacific bluefin tuna T. orientalis in Japan. Over 70 C. orientalis adults were retrieved from a single gill of an infected southern bluefin tuna and numerous eggs were observed in the gill filaments. These suggest possible pathology of C. orientalis on T. macoyii. In addition, we obtained new information on morphological characteristics and molecular sequences of Cardicola forsteri infecting heart of T. macoyii. This is the first report of C. orientalis in T. macoyii which may have a significant impact on the ranching industry of southern bluefin tuna.