Holothurian assemblages before the harvest-boom era in inner reefs of Ishigaki Island, focusing on population dynamics of lollyfish <i>Holothuria atra</i> Jäger, 1833

DOI Web Site Web Site 40 References
  • Nishihama Shirou
    Fisheries Technology Institute, Japan Fisheries Research and Education Agency
  • Tanita Iwao
    Yaeyama Field Station, Fisheries Technology Institute, Japan Fisheries Research and Education Agency

Bibliographic Information

Other Title
  • Holothurian assemblages before the harvest-boom era in inner reefs of Ishigaki Island, focusing on population dynamics of lollyfish Holothuria atra Jager, 1833

Search this article

Description

<p>Distribution and abundance of holothurians before the boom of fisheries in the 1990s were analyzed in relation to types of bottom sediment and biomes in inner reefs of Ishigaki Island, Okinawa, Japan. The data had been collected continuously over three years at Yoshihara and once at three other sites. Fifteen species were found, among which the dominant Holothuria atra and Stichopus chloronotus were abundant on bottoms with sand and seagrass, and those with sand and coral cobbles, respectively. The continuous survey at Yoshihara revealed that the overall density of H. atra was 2 to 3 ind. m−2, which was the highest among values reported previously, and spatial-temporal distribution of H. atra was almost stable throughout the research period, but the distribution of St. chloronotus fluctuated irregularly. The density of H. atra fluctuated seasonally (high in winter and low in summer) and was correlated negatively with air temperature and irradiation, and positively with cloud cover. The body length of H. atra became longer in summer and shorter in winter. The frequency of asexual reproduction (fission) was estimated at less than 1% of annual recruitment, and the growth rate was estimated to be low (K=0.0845 in von Bertalanffy equation). The high density and slow growth suggested that the H. atra population had reached carrying capacity at Yoshihara. The sand-coated ratio of H. atra was positively correlated with wind speed, however, no trend was found with the spatial-temporal variation in the density and distribution of the sand-coated individuals.</p>

Journal

  • Plankton and Benthos Research

    Plankton and Benthos Research 16 (3), 165-178, 2021-08-06

    The Plankton Society of Japan, The Japanese Association of Benthology

References(40)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top