Notes on the feeding habits of the Okinawan fishing spider, Dolomedes orion (Araneae: Pisauridae), in the southwestern islands of Japan

Research on the Okinawan fishing spider, Dolomedes orion, reveals its role as a significant predator in semi-aquatic ecosystems, with a diet encompassing a broad range of prey, including insects, crustaceans, and vertebrates. Observations from Amami Oshima Island and literature reviews indicate that this large cursorial spider, the largest in Japan, primarily preys on high-energy resources such as freshwater crabs, prawns, endemic frogs (Rana ulma, Odorrana narina), and an Okinawa tree lizard (Japalura polygonata polygonata). Nearly half (43%) of its prey items belong to these large-sized groups, suggesting a preference for substantial energy sources to meet its growth demands. This study highlights the ecological importance of Dolomedes orion in the southwestern islands of Japan.

Baba, Y. G., Watari, Y., Nishi, M., & Sasaki, T. (2019). Notes on the feeding habits of the Okinawan fishing spider, Dolomedes orion (Araneae: Pisauridae), in the southwestern islands of Japan. The Journal of Arachnology, 47(1), 154. https://doi.org/10.1636/0161-8202-47.1.154