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Shimono Tomoharu


Mortality causes of the bivalve, Ruditapes philippinarum, in the intertidal zone of the Seto Inland Sea, eastern Yamaguchi Prefecture : A field study by caging experiments

Journal of National Fisheries University Volume 57 Issue 3 Page 165-173
published_at 2009-02
57-3-165-173.pdf
[fulltext] 1.07 MB
Title
山口県東部瀬戸内海沿岸におけるアサリの減耗要因 : 野外ケージ実験による検討
Mortality causes of the bivalve, Ruditapes philippinarum, in the intertidal zone of the Seto Inland Sea, eastern Yamaguchi Prefecture : A field study by caging experiments
Creators Matsuda Haruna
Creators Hamano Tatsuo
Creators Shimono Tomoharu
Creators Yamana Yusuke
Source Identifiers
Creator Keywords
Cages Mortality causes Predator control Ruditapes philippinarum Scaphechinus mirabilis
To evaluate the mortality of the bivalve Ruditapes philippinarum caused by predatory animals, two experiments were conducted in the coastal area of the western Seto Inland Sea around the Tana Marine Biological Laboratory, Yamaguchi Prefecture, Japan. On the tidal flat, four cages of different designs were set on the bottom, and 200 individuals of R. philippinarum (14.8 mm in average shell length [SL]) were put into each cage (Experiment 1). From the number of survivors after four months, the mortalities due to environmental factors, predators entering from the upper side and those from the bottom were estimated to be 0.615, 0.225 and 0.170, respectively. On the other hand, in the raft experiment, containers filled with sand and R. philippinarum juveniles (< 5 mm SL) were set into the cages hanging from the raft at depths of 1, 3, 5 and 7 m (Experiment 2 ). Five individuals of the sand dollar Scaphechinus mirabilis were also introduced into the container at each depth. Four months later, large-sized individuals (20-30 mm SL) of R. philippinarum were observed in the containers, indicating that the juvenile bivalves survived and grew even in the presence of S. mirabilis. Therefore, this study shows that S. mirabilis is not the major cause of mortality of R. philippinarum.
Languages jpn
Resource Type departmental bulletin paper
Publishers National Fisheries University
Date Issued 2009-02
File Version Version of Record
Access Rights open access
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[ISSN]0370-9361