a1 Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, Okinawa 905-0227, Japan.
a2 Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, Okinawa 905–0227, Japan.
a3 Ocean Research Institute, University of Tokyo, Tokyo 164-8639, Japan.
a4 Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8567, Japan.
Ocean acidification is now recognized as a threat to marine ecosystems; however, the effect of ocean acidification on fertilization in marine organisms is still largely unknown. In this study, we focused on sperm flagellar motility in broadcast spawning reef invertebrates (a coral and a sea cucumber). Below pH 7.7, the pH predicted to occur within the next 100 years, sperm flagellar motility was seriously impaired in these organisms. Considering that sperm flagellar motility is indispensable for transporting the paternal haploid genome for fertilization, fertilization taking place in seawater may decline in the not too distant future. Urgent surveys are necessary for a better understanding of the physiological consequences of ocean acidification on sperm flagellar motility in a wide range of marine invertebrates.
(Received May 14 2009)
(Accepted July 16 2009)
(Online publication November 20 2009)
c1 All correspondence to: Ryota Suwa. Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, Okinawa 905-0227, Japan. Tel: +81 980 47 3049. Fax: +81 980 47 4919. e-mail: firstname.lastname@example.org
5 These authors contributed equally to this work.