著者

林 芳弘 神田 猛

出版者

宮崎大学農学部

雑誌

宮崎大学農学部研究報告 = Bulletin of the Faculty of Agriculture, University of Miyazaki (ISSN:05446066)

巻号頁・発行日

vol.60, pp.21-28, 2014-03

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2008年11月,2009年1月,5月,7月に,四万十川河口域の本流と測流で,水深0.5mの水域に出現する浮遊性カイアシ類を調べたところ,主に汽水性のカラヌス目であるSinocalanus tenellus,Pseudodiaptomus inopinus,Acartia tsuensisの3種を確認した。側流におけるカイアシ類の平均密度は0.52±0.90個体/L(平均値±標準偏差,11月)~75.75±68.97個体/L(5月)だった。本流では,5月を除くと11月の0.03±0.03個体/Lが最高だった。従って,カイアシ類の密度は本流よりも側流の方が高いと言えた。側流は,本流より水流が弱いために,カイアシ類が高い密度で出現すると考えられる。また,夏季には,カイアシ類の繁殖に好適な水温となることから,特に密度が高くなると考えられる。

著者

三浦 知之 三浦 要 富岡 宏 佐伯 めぐみ 三橋 利恵

出版者

宮崎大学農学部

雑誌

宮崎大学農学部研究報告 = Bulletin of the Faculty of Agriculture, University of Miyazaki (ISSN:05446066)

巻号頁・発行日

vol.58, pp.51-68, 2012-02-24

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The faunal composition of benthic mollusks, crustaceans and a brachiopod was investigated in the East and West inlets (32°29'N, 131°41'E) of Kadogawa Bay, on the East central coast of the Kyusyu island, Miyazaki Japan. There are sea-grass bed areas consisting of Zostera marina, Z. japonica and Halophila nipponica in the East and West Iorigawa inlets. The sea-grass bed of the East inlet is wider than that of the West. The former is fringed by a natural rocky shore in its eastern margin, however the latter is guarded by the concrete embankment and situated between a small fishery port and a public park of buried sea bottom. The benthic communities were investigated 26 times from November 2006 to July 2011 and their components were compared and discussed.In total, 206 benthic animal species including 87 gastropods, 30 bivalves and 50 decapod crustaceans were recorded. Among these benthic species, 97 were known only from East inlet and 70 species were known from both inlets. We could recognize the benthic community richness in the Fast inlet and it thought to be resulted by the wider area and rich environments, such as, the rocky shore without artificial concrete constructions.