Infection by and Molecular Features of Learedius learedi (Digenea: Schistosomatoidea) in Green Sea Turtles (Chelonia mydas) on the Ogasawara Islands, Japan

A study of green sea turtles (Chelonia mydas) on the Ogasawara Islands, Japan, revealed that the blood fluke Learedius learedi exhibits extremely high genetic diversity, with haplotypes distinct from those found in other Pacific rookeries. This suggests that L. learedi may have coevolved with its host turtles on these islands. Researchers analyzed 26 infected turtles using morphological and molecular techniques, including ITS2 and 28S ribosomal DNA sequencing, confirming the species identity of the flukes and distinguishing them from related genera like Hapalotrema. Additionally, mitochondrial COI gene analysis showed significant genetic variation, supporting the hypothesis that L. learedi has differentiated alongside its host population on the Ogasawara Islands.

Kitayama, C., Hayashi, K., Ohari, Y., Kondo, S., Kuroki, T., Shibahara, T., & Itagaki, T. (2019). Infection by and Molecular Features of Learedius learedi (Digenea: Schistosomatoidea) in Green Sea Turtles (Chelonia mydas) on the Ogasawara Islands, Japan. Journal of Parasitology, 105(4), 533. https://doi.org/10.1645/19-24