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Stable carbon and nitrogen isotopes were used to investigate nutrient pathways and trophic relationships from the rice-crab system in Panjin,Liaoning Province,China. Values of δ 13 C ranged from-27.38‰±0.44‰ to-18.34‰±0.26‰ and δ 15 N ranged from 1.10‰±0.88‰ to 9.33‰±0.57‰. Pseudorasbora parva(Stone moroko) had the highest δ 13 C and δ 15 N values. The lowest δ 13 C values were obtained for the macrophytes and the lowest δ 15 N value was found in sediments. Stable carbon and nitrogen isotopes were used to determine the contribution of different food items to the diets of crabs. The δ 13 C results indicated that the P seudorasbora parva made the greatest contribution to the diet of E riocheir sinensis(Chinese mitten crab),while the δ 15 N results indicated that most food items contributed more than 10% to the diet of the crab. There were three trophic levels identified in the system(Levels 0–2). The crab Eriocheir sinensis,fish Pseudorasbora parva and Misgurnus anguillicaudatus(Oriental weatherfish),and the oligochaete L imnodrilus hoffmeisteri(Limnodrilus worm),were at the second level,zooplankton were at the first level and suspended particulate matter and macrophytes were at trophic position 0.
Stable carbon and nitrogen isotopes were used to investigate nutrient pathways and trophic relationships from the rice-crab system in Panjin, Liaoning Province, China. Values of δ 13 C ranged from-27.38 ‰ ± 0.44 ‰ to-18.34 ‰ ± 0.26 ‰ and δ 15 N ranged from 1.10 ‰ ± 0.88 ‰ to 9.33 ‰ ± 0.57 ‰. Pseudorasbora parva (Stone moroko) had the highest δ 13 C and δ 15 N values. The lowest δ 13 C values were obtained for the macrophytes and the lowest δ 15 N value was found in sediments. Stable carbon and nitrogen isotopes were used to determine the contribution of different food items to the diets of crabs. The δ 13 C results indicated that the P seudorasbora parva made the greatest contribution to the diet of E riocheir sinensis (Chinese mitten crab), while the δ 15 N results indicate that most food items contributed more than 10% to the diet of the crab. There were three trophic levels identified in the system (Levels 0-2). The crab Eriocheir sinensis, fish Pseudorasbora parva and Misgu rnus anguillicaudatus (Oriental weatherfish), and the oligochaete L imnodrilus hoffmeisteri (Limnodrilus worm), were at the second level, zooplankton were at the first level and suspended particulate matter and macrophytes were at trophic position 0.