Spatial distribution and dietary overlap between Japanese anchovy Engraulis japonicus and moon jellyfish Aurelia aurita in the Seto Inland Sea, Japan


  • Jun Shoji Takehara Fisheries Research Station, Hiroshima University
  • Ken-Ichiro Mizuno Takehara Fisheries Research Station, Hiroshima University
  • Masayuki Yamamoto Kagawa Prefecture Fisheries Experimental Station
  • Todd William Miller Center for Marine Environmental Studies, Ehime University
  • Hideki Hamaoka Center for Marine Environmental Studies, Ehime University
  • Koji Omori Center for Marine Environmental Studies, Ehime University



ichthyoplankton, stable isotope analysis, Sea of Hiuchi, Hiroshima Bay


Biological and physical surveys were conducted in order to investigate the relationship between environmental conditions and the distribution of ichthyoplankton and jellyfish, and dietary overlap between the ichthyoplankton and jellyfish in the Seto Inland Sea (SIS), Japan. Ichthyoplankton, copepods, and jellyfish were collected during two cruises in July 2005 in the Sea of Hiuchi and in July 2006 in Hiroshima Bay within the SIS. Sea surface temperature (˚C), salinity, bottom-layer dissolved oxygen (mg l-1) and the abundance (no. m-2) of fish eggs and larvae were significantly higher in the Sea of Hiuchi. Japanese anchovy was most dominant (69.3% in number of eggs and 52.3% in number of larvae) among the ichthyoplankton. Mean jellyfish biomass (g m-2) in Hiroshima Bay was significantly higher (50-folds) than that in the Sea of Hiuchi. Moon jellyfish was the most dominant among the jellyfish collected, accounting for 85.6% in wet weight. Surface temperature had a significant effect on fish egg and larval distribution: abundance of fish eggs and larvae increased with increasing temperature. Jellyfish abundance was negatively correlated with the bottom-layer oxygen concentration. Stable isotope analysis indicated dietary overlap between the Japanese anchovy and the moon jellyfish in Hiroshima Bay.


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How to Cite

Shoji J, Mizuno K-I, Yamamoto M, Miller TW, Hamaoka H, Omori K. Spatial distribution and dietary overlap between Japanese anchovy Engraulis japonicus and moon jellyfish Aurelia aurita in the Seto Inland Sea, Japan. scimar [Internet]. 2009Oct.30 [cited 2023Oct.4];73(S1):191-8. Available from: