Marine Biology

, Volume 155, Issue 1, pp 105–112

Phylogenetic analyses of potentially free-living Symbiodinium spp. isolated from coral reef sand in Okinawa, Japan

  • Mamiko Hirose
  • James D. Reimer
  • Michio Hidaka
  • Shoichiro Suda
Original Paper

DOI: 10.1007/s00227-008-1011-2

Cite this article as:
Hirose, M., Reimer, J.D., Hidaka, M. et al. Mar Biol (2008) 155: 105. doi:10.1007/s00227-008-1011-2

Abstract

The existence of “free-living” Symbiodinium that can form symbioses with hosts is implied by the presence of hosts that produce Symbiodinium-free gametes and expulsion and/or expelled symbiotic algae from host. However, it is still unclear if potentially symbiotic Symbiodinium are found “free-living” in the coral reef environment. Sixteen Symbiodinium strains were established from samples taken from three sampling locations of coral reef sand in Okinawa, Japan. Phylogenetic analyses of the partial large subunit ribosomal DNA (28S-rDNA) and the internal transcribed spacer of ribosomal DNA (ITS-rDNA) conclusively showed that all 16 isolates belonged to Symbiodinium clade A sensu Rowan and Powers (1991). The lack of other Symbiodinium clades besides clade A in this study may be due to other clades not being readily culturable under culture conditions used here. The new isolates could be phylogenetically divided into four groups, though no sequences were identical to previously reported Symbiodinium. Two of the four groups were closely related to symbiotic Symbiodinium clade A isolated from a variety of host species. One isolate group formed a highly supported monophyly with Symbiodinium types that have previously been characterized as “free-living”. The remaining isolate group, although within clade A, was quite divergent from other clade A Symbiodinium. These results indicate that novel diversity of free-living Symbiodinium exists in coral sand.

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Mamiko Hirose
    • 1
  • James D. Reimer
    • 1
    • 2
  • Michio Hidaka
    • 1
  • Shoichiro Suda
    • 1
  1. 1.Department of Chemistry, Biology and Marine ScienceUniversity of the RyukyusNishiharaJapan
  2. 2.Research Program for Marine Biology and Ecology, Extremobiosphere Research CenterJapan Agency for Marine-Earth Science and Technology (JAMSTEC)YokosukaJapan