Journal of the Marine Biological Association of the United Kingdom

Research Article

Molecular investigations of the stalked barnacle Vulcanolepas osheai and the epibiotic bacteria from the Brothers Caldera, Kermadec Arc, New Zealand

Yohey Suzukia1 c1, Masae Suzukia2, Shinji Tsuchidaa2, Ken Takaia2, Koki Horikoshia2, The Late Alan J. Southwarda3, William A. Newmana4 and Toshiyuki Yamaguchia5

a1 Research Institute for Geo-resources & Environment, National Institute of Advanced Industrial Science & Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8567, Japan

a2 Extremobiosphere Research Center, Japan Agency for Marine-Earth Science & Technology, 2-15 Natsushima-cho, Yokosuka 237-0061, Japan

a3 Marine Biological Association of the United Kingdom, Citadel Hill, Plymouth, PLI 2PB Devon, UK

a4 Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92093-0202, USA

a5 Marine Biosystems Research Center, Chiba University, 1-33, Yayogi-cho, Inage, Chiba 263-8522, Japan

Abstract

The hydrothermal-vent barnacle Vulcanolepas osheai of the subfamily Neolepadinae is one of the most conspicuous organisms at the Brothers Caldera, south Kermadec Arc, New Zealand. Like a neolepad species found in the Lau Basin, V. osheai harbours filamentous bacteria on its elongated cirral setae. To define the phylogenetic affiliation of the epibiotic bacteria and the nutrition of the barnacle host, we conducted molecular phylogenetic and isotopic analyses. Analysis of 16S rRNA gene sequences of microbial communities on the cirral setae showed that among 91 bacterial sequences investigated, 28 sequences were related to the xs025B-proteobacterial endosymbiont of Alviniconcha aff. hessleri; 11 sequences were related to the epibiont of the bresiliid shrimp Rimicaris exoculata. Fluorescence in situ hybridization showed that in contrary to results from the 16S rRNA gene-sequence library, approximately 80% of the filamentous bacteria hybridized with a probe targeting the sequences related to the epibiont of the bresiliid shrimp R. exoculata. The fatty-acid profiles of the filamentous bacteria and the host barnacle both contained high levels of monounsaturated C16 and C18 fatty acids, and the carbon isotopic compositions of the biomass and monounsaturated C16 and C18 fatty acids of both the bacteria and barnacle were nearly identical. This would suggest that the nutrition of the barnacle is highly dependent on bacteria thriving around the barnacle, including the epibiotic bacteria.

(Received April 27 2006)

(Accepted January 13 2009)

(Online publication May 15 2009)

Correspondence:

c1 Correspondence should be addressed to: Y. Suzuki, Research Institute for Geo-resources & Environment, National Institute of Advanced Industrial Science & Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8567, Japan email: yohey-suzuki@aist.go.jp