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 (<1% d⁻¹). Various food items were identified in the fish diets, including phytoplankton, zooplankton, benthic algae, and insects. Despite some dietary overlap, a comparison of indices of relative importance clearly indicated that foods were consumed at different proportions by different species within each species combination. The stable isotope analysis also revealed various degrees of trophic niche partitioning among species. The standard ellipse areas of isotopic niches showed higher feeding plasticity in many of the herbivorous and omnivorous fishes than in the prawn or the carnivorous fish C. striata.

在有机稻-鱼系统中放养了四种鱼类和对虾种类的组合，以检查它们的生长性能，摄食习惯，竞争性相互作用和食物网结构。物种组合为：（I）湄公河下游国家稻－鱼系统中常见的三种鱼类，分别为：Barbonymus gonionotus，Cyprinus carpio和Oreochromis niloticus；（二）相同的三个物种加上巨型淡水虾罗氏沼虾；（III）湄公河原产的三种草食性鱼类，即B. gonionotus，Barbonymus schwanenfeldii和Cirrhinus microlepis；（IV）食草和杂食鱼类B. gonionotus，C。microlepis和Trichogaster胸大肌以及肉食性鱼类Channa striata。使用比增长率（SGR）检查生长性能，并通过胃含量和稳定同位素（碳和氮）分析检查喂养习惯。除纹状线虫（C. striata）生长速度较慢（<1％d ^-1）外，所有鱼类和对虾种类均表现出大约1-2％d ^-1的SGR。）。鱼的饮食中确定了各种食物，包括浮游植物，浮游动物，底栖藻类和昆虫。尽管在饮食上存在一些重叠，但对相对重要性指数的比较清楚地表明，每种物种组合中不同物种所消耗的食物比例不同。稳定的同位素分析还揭示了物种之间不同程度的营养生态位分配。同位素壁ches的标准椭圆区域在许多食草和杂食性鱼中的摄食可塑性比对虾或食肉鱼条纹。更高。