Marine Biology

, Volume 151, Issue 6, pp 2099–2107 | Cite as

Seasonal change of species composition, abundance, and reproduction of solitary entoprocts in Okinawa Island, the Ryukyu Archipelago, Japan

  • Tohru IsetoEmail author
  • Yasuaki Yokuta
  • Euichi Hirose
Research Article


Monthly samplings of solitary entoprocts were carried out at Mizugama and Ginowan Fishery Port, Okinawa Island, the central Ryukyus, Japan from November 2000 to November 2001. We examined the entoproct populations on the glass slides that had been placed at the two sites for 2 months, and a total of 18,322 individuals of solitary entoprocts were recorded. They were Loxomitramizugamaensis, L. ryukyuensis, L. tetraorganon, Loxosomella aloxiata, L. intragemmata, L. lecythifera, L. monocera, L. stomatophora, and Loxocorone allax. Our analyses indicate that (1) the abundance of solitary entoprocts in this region is high in summer and low in winter, (2) most species reproduce by budding all year round, and (3) sexual reproduction is restricted to a short period in summer (July or August).


Coral Reef Sexual Reproduction Annual Average Reef Flat Asexual Reproduction 
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We wish to express our gratitude to Prof. Terufumi Ohno (Kyoto University Museum) for his encouragement. Thanks are also due to Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus for providing the data of the surface water temperature. This study was supported in part by a subvention made to graduate students by the Research Institute of Marine Invertebrates, a Sasagawa Scientific Research Grant from the Japan Science Society, a Research Fellowship for Young Scientists awarded by the Japan Society for the Promotion of Science, and the twenty-first Century COE program of University of the Ryukyus. The experiments performed here complied with the current laws of Japan.


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Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  1. 1.Marine Learning Center OkinawaJapan
  2. 2.Department of Chemistry, Biology and Marine Science, Faculty of ScienceUniversity of the RyukyusOkinawaJapan

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