Growth and feeding behavior of fishes in organic rice–fish systems with various species combinations

• Published in: Aquaculture reports 2021-07, Vol.20, p.100663, Article 100663
• Main Authors: Saowakoon, Samnao, Saowakoon, Krittima, Jutagate, Achara, Hiroki, Mikiya, Fukushima, Michio, Jutagate, Tuantong
• Format: Article
• Language: English
• Subjects: aquaculture; Barbonymus gonionotus; carbon; carnivores; Channa striata; Cirrhinus; Cyprinus carpio; food webs; growth performance; Index of relative importance; Macrobrachium rosenbergii; Mekong River; nitrogen; omnivores; Oreochromis niloticus; phytoplankton; shrimp; Specific growth rate; Stable isotope; stable isotopes; stomach; Stomach content; Trichogaster; zooplankton
• ISSN: 2352-5134; 2352-5134
• DOI: 10.1016/j.aqrep.2021.100663

•Various species combinations of fishes and prawn were raised in organic rice–fish systems.•Fish and prawn, especially herbivores and omnivores, exhibited a high and acceptable growth performance.•The index of relative importance of food items revealed contrasting food preferences among fish and prawn species.•Stable isotope ratios of carbon and nitrogen confirmed trophic niche partitioning in all combinations throughout the experiment.•High feeding plasticity and adaptability to paddy field environment warrant species combinations employed in rice–fish system. Four combinations of fish and prawn species were stocked in organic rice–fish systems to examine their growth performance, feeding habits, competitive interactions, and food-web structure. The species combinations were: (I) three fish species commonly stocked in rice–fish systems in the Lower Mekong countries, namely Barbonymus gonionotus, Cyprinus carpio, and Oreochromis niloticus; (II) the same three species plus the giant freshwater prawn Macrobrachium rosenbergii; (III) three herbivorous fishes native to the Mekong River, namely B. gonionotus, Barbonymus schwanenfeldii, and Cirrhinus microlepis; and (IV) the herbivorous and omnivorous fishes B. gonionotus, C. microlepis, and Trichogaster pectoralis, together with the carnivorous fish Channa striata. Growth performance was examined using specific growth rate (SGR), and feeding habit was examined through stomach content and stable isotope (carbon and nitrogen) analyses. All fish and prawn species exhibited SGRs of roughly 1–2% d−1 except for C. striata, which had a slower growth rate (