Experimental clearance rate and intraguild predation of jellyfish Cyanea nozakii

• Published in: Journal of oceanology and limnology Vol. 42; no. 1; pp. 128 - 140
• Main Authors: Wang, Pengpeng, Zhang, Fang, Sun, Song, Lü, Shuguo
• Format: Journal Article
• Language: English
• Published: Heidelberg Science Press 01.01.2024; Springer Nature B.V; CAS Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China; Jiaozhou Bay Marine Ecosystem Research Station,Chinese Academy of Sciences,Qingdao 266071,China; Center for Ocean Mega-Science,Chinese Academy of Sciences,Qingdao 266071,China%CAS Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China; Center for Ocean Mega-Science,Chinese Academy of Sciences,Qingdao 266071,China%Institute of Marine Ecology and Environment,Hainan Academy of Environmental Sciences,Haikou 570100,China; Laboratory for Marine Ecology and Environmental Sciences,Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,China; University of Chinese Academy of Sciences,Beijing 100049,China
• Subjects: Aquatic crustaceans; Blooms; Body size; Chaetognatha; China; Clearances; Cnidaria; Copepoda; Cyanea nozakii; Earth and Environmental Science; Earth Sciences; Fish; Fish larvae; Interspecific relationships; Larvae; Marine ecosystems; Marine invertebrates; Oceanography; Offshore; Ontogeny; Organisms; Plankton; Population regulation; Predation; predator-prey relationships; Predators; Prey; Prey selection; Research Paper; Scyphozoa; Trophic relationships; Zooplankton; China; Scyphomedusae; predation rate; prey selection; feeding mechanism; gelatinous organisms
• ISSN: 2096-5508; 2523-3521
• DOI: 10.1007/s00343-023-2321-4

Cyanea nozakii , a common jellyfish distributed in offshore China, has a complex trophic relationship with other zooplankton groups. However, few studies have reported the predation rates and prey selection patterns of C. nozakii medusae on different prey items. Research is also lacking on the intraguild predation of Aurelia coerulea (another common bloom jellyfish in offshore China) by C. nozakii . To address the knowledge gaps, the clearance rates of C. nozakii for different prey items, including copepods (small<1 000 µm and large>1 000 µm), fish larvae, and gelatinous prey (hydromedusae, A. coerulea ephyrae, and chaetognaths), were measured. The influence of predator size on the clearance rate was also determined. Additionally, we examined the intraguild predation of C. nozakii on A. coerulea medusae. The clearance rates of C. nozakii varied widely with prey organisms, being independent of prey concentrations. Gelatinous organisms, except for chaetognaths, were captured with considerably high efficiency, followed by fish larvae and copepods, indicating the preferential prey selection of gelatinous organisms by C. nozakii . The clearance rate increased linearly with the cross-sectional area of C. nozakii . Body size in medusae may, to some extents, underpin their capacity to capture more prey by increasing the encounter rate and capture success through ontogeny. C. nozakii preyed voraciously on A. coerulea in high feeding efficiency, but the clearance rate decreased with increasing A. coerulea (as prey) size. This phenomenon of intraguild predation suggests a speculative hypothesis of potential population regulation of A. coerulea by C. nozakii . The information regarding the feeding ecology of C. nozakii reported in this study is important for understanding plankton dynamics in marine ecosystems with extensive occurrences of this jellyfish.