Aoi Tsuyuki‡, Yuki Oya‡, Hiroshi Kajihara‡Corresponding author: Aoi Tsuyuki ( tykamsp0430@gmail.com ) Academic editor: Natalia Luchetti © Aoi Tsuyuki, Yuki Oya, Hiroshi Kajihara. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Citation:
Tsuyuki A, Oya Y, Kajihara H (2020) First record of Stylostomum ellipse (Dalyell, 1853) (Platyhelminthes, Polycladida) from the Pacific Ocean. Check List 16(3): 773-779. https://doi.org/10.15560/16.3.773 |  |
The polyclad flatworm Stylostomum ellipse (Dalyell, 1853) has hitherto been recorded from the Antarctic region, Mediterranean Sea, Patagonian region, Scandinavia, South Africa, and South Georgia Island. In this study, we report S. ellipse for the first time from the Pacific Ocean based on specimens collected in Hokkaido, northern Japan. Our specimens are morphologically identifiable as S. ellipse, but may represent a biologically different species from a population of the Mediterranean Sea. This is because, based on the previous genetic data of other cotylean species, the observed uncorrected p-distance 0.02160 between the two distinct populations in terms of a partial 972 bp region of the 28S rDNA sequence may be great enough to separate the species biologically.