Seasonal and geographical distribution of near-surface small photosynthetic eukaryotes in the western North Pacific determined by pyrosequencing of 18S rDNA.
In this study, we investigated the distribution of small photosynthetic eukaryotes in the near-surface layer of the western North Pacific at four stations, including two oceanic stations where the subarctic Oyashio and subtropical Kuroshio currents influence a transition region and the bay mouth and head of the Sendai Bay, from April 2012 to May 2013. Flow cytometry was applied to sort small photosynthetic eukaryotes (<5 μm), and high-throughput sequencing of 18S rDNA was performed. Our taxonomic analysis showed that 19/195 operational taxonomic units (OTUs) were frequently distributed among all sites. Composition analysis showed that the OTUs had characteristic patterns and were divided into four main groups. Two groups reflected the low-saline water and winter season, with the characteristic OTUs belonging to diatoms; Chaetoceros and Leptocylindrus were characteristic of low saline water, and two diatom genera (Minidiscus and Minutocellus) and Cryptomonadales-related OTUs were prevalent in the winter. Our results indicate that the community composition of small photosynthetic eukaryotes seasonally changes in a dynamic manner according to variations in water properties.
Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan tak-g-k@ees.hokudai.ac.jp.
Takafumi
T
Kataoka
Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan.
Haruyo
H
Yamaguchi
Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan.
Mayumi
M
Sato
Tohoku National Fisheries Research Institute, Shinhama-cho 3-27-5, Shiogama, Miyagi 985-0001, Japan.
Tsuyoshi
T
Watanabe
Tohoku National Fisheries Research Institute, Shinhama-cho 3-27-5, Shiogama, Miyagi 985-0001, Japan.|Hokkaido National Fisheries Research Institute, Katsurakoi 116, Kushiro, Hokkaido 085-0802, Japan.
Yukiko
Y
Taniuchi
Tohoku National Fisheries Research Institute, Shinhama-cho 3-27-5, Shiogama, Miyagi 985-0001, Japan.
Akira
A
Kuwata
Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan.
Masanobu
M
Kawachi
D004275:DNA, Ribosomal; D017377:Diatoms; D004784:Environmental Monitoring; D056890:Eukaryota / Q000145:classification / Q000235:genetics* / Q000254:growth & development; D009792:Oceans and Seas; D010140:Pacific Ocean; D010788:Photosynthesis; D012337:RNA, Ribosomal, 18S; D012621:Seasons; D012623:Seawater / Q000737:chemistry
D004275:DNA, Ribosomal; D012337:RNA, Ribosomal, 18S
18S rDNA; Kuroshio–Oyashio transition; pyrosequencing; small eukaryotic phytoplankton; spatiotemporal distribution