First records of Microphis retzii (Syngnathidae) from the Okinawa Islands, Ryukyu Islands, Japan

Two specimens of Microphis retzii (Bleeker, 1856) (Syngnathidae) were collected from two rivers on Okinawa-jima island, Okinawa Islands, Ryukyu Islands, Japan. Microphis retzii is distributed in the western Pacific Ocean, including Japan, Taiwan, China (Guangdong Province), the Philippines, Indonesia, Pohnpei Island, and the Samoa Islands. In Japanese waters, the species has been previously recorded along the Pacific coast of Honshu from Shizuoka to Miyazaki prefectures, and on Tanega-shima island, Amami-oshima island, and the Yaeyama Islands. Thus, the presently reported specimens, described herein in detail, represent the first records of M. retzii from the Okinawa Islands.