Effects of low dissolved oxygen on planula settlement, polyp growth and asexual reproduction of Aurelia aurita

By Haruto Ishii, Toshifumi Ohba, Takeshi Kobayashi. 2008

88 citations recorded by the source corpus.

Tokyo Bay is one of the most eutrophicated bays in Japan, and mass occurrences of scyphozoan jellyfish Aurelia aurita have often been observed with progress of eutrophication. In the coastal environment, the abundance of substrates suitable for A. aurita polyps are obviously increasing by reclamation. However, most suitable substrates for settling, except in the bottom-layer in the innermost part of Tokyo Bay, are occupied by other sessile organisms such as mussels, barnacles or ascidians. The bottom layer is characterized by low DO concentrations (≦2.0 ml O2 L−1) that turn to hypoxia during summer, resulting in low recruitment and low growth of other sessile organisms. To elucidate the mechanism by which mass occurrence of jellyfish occurs, adaptative behavior to hypoxia in planula larvae and the polyp stage was experimentally studied. In the present study, planula settlement was promoted by a decrease in DO concentrations, and apparent growth of polyps and production of daughter polyps by asexual budding were also observed, even in the polyps cultured in hypoxic waters. Moreover A. aurita polyps cultured under hypoxic conditions began strobilation and ephyrae were liberated after the DO concentration levels were restored. It is suggested that the occurrence of hypoxic waters is rather favorable for the survival, growth and asexual reproduction of A. aurita polyps, and it can directly contribute to the consequent production of A. aurita ephyrae in the next spring within Tokyo Bay.

Subfields: Environmental Chemistry, Oceanography, Paleontology

View Paper: https://www.semanticscholar.org/paper/d983b444a877be9c8161366ac3d4a3f371314ff8

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In Environmental Chemistry

1. Daniel Pauly
2. Chang-Hoon Han
3. A. Morandini
4. S. Uye
5. Antonio C. Marques

In Oceanography

1. Chang-Hoon Han
2. Daniel Pauly
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4. K. Kleisner
5. A. Morandini
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In Paleontology

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3. Chang-Hoon Han
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Citations in the corpus

• Is global ocean sprawl a cause of jellyfish blooms (2013, unknown): “A aurita Polyp Tokyo Bay (Japan) On pylon in bottom hypoxic layer Ishii et al. (2008); Ishii and where other sessile organisms are Katsukoshi (2010) absent”
• Combined effects of food supply and temperature on asexual reproduction and somatic growth of polyps of the common jellyfish Aurelia aurita s.l. (2010, background): “Previous studies have shown that temperature, salinity, light, oxygen concentration, food supply, etc. influence the polyp asexual reproduction of the genus Aurelia (Coyne 1973, Keen & Gong 1989, Ishii & Watanabe 2003, Ishii et al. 2008, Purcell 2007, Willcox et al. 2007, Liu et al. 2009).”
• Increasing jellyfish populations: trends in Large Marine Ecosystems (2012, background): “in Tokyo Bay, Japan are more likely due to the effects of eutrophication (Nomura & Ishimaru, 1998; Ishii et al., 2008).”
• Human forcing of the copepod–fish–jellyfish triangular trophic relationship (2011, background): “…& Turner, 1998), which may further decrease both habitat space and reproduction of most marine species, but not jellyfish, which are tolerant of low oxygen concentration (Rutherford & Thusen, 2005; Shoji et al., 2005), as are the benthic scyphistomae (Condon et al., 2001; Ishii et al., 2008).”
• Revision of the genus Chrysaora Peron & Lesueur, 1810 (Cnidaria: Scyphozoa) (2010, background): “& Jarms, G. (2007) Substrate choice and settlement preferences of planula larvae of five Scyphozoa (Cnidaria) from German Bight, North Sea.”