First records of five appendicularian species (Tunicata, Appendicularia) in the western North Pacific

Abstract To date, there are no records of appendicularian assemblages or associated investigations in the waters adjacent to the Kuroshio Current around the Nansei Islands, Japan. In this study, plankton samplings were conducted with a North Pacific Standard net hauled vertically from a depth of 200 m to the surface to investigate the appendicularian community structure in such waters. Five species were newly recorded in the western North Pacific, each representing a new geographical record for the region. The new records include Fritillaria aequatorialis, Fritillaria pacifica, Fritillaria pellucida omani, Appendicularia tregouboffi , and Kowalevskia oceanica , which belong to appendicularian families Fritillariidae and Kowalevskiidae. Among them, F. aequatorialis, A. tregouboffi , and K. oceanica represent the first records in the entire Pacific Ocean. Owing to the under sampling of appendicularian assemblages in tropical and subtropical waters in the Pacific Ocean and a lack of systematic quantitative and qualitative research on this topic, these species might have been overlooked for a long time in Japanese waters.