Abstract: The Xijiang Oxbow locates in the Anqing section of Yangtze River and is an important ex-situ conservation base for the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis). In order to evaluate the food-supply capacity for the Yangtze finless porpoise in the Xijiang oxbow, hydroacoustic measurements were performed using a 200 kHz BioSonics DT-X split beam echosounder from August, 2016 to January, 2017, fish community was investigated with electric fishing method at the same time. Fish production was assessed with average biomass and P/B-, the maximum sustainable yield was evaluated with Y=0.5P. The results indicated that: a total of 34 fish species were collected in our survey, fish density was 1.4-5 662.3 ind./1 000 m3, with an average of 253.3 ind./1 000 m3 in summer, while it was 0.8-2 338.1 ind./1 000 m3, with an average of 127.5 ind./1 000 m3 in winter. The standing crop was about 155 000 kg in summer and 101 000 kg in winter.According to morphological characters and spatial distribution of fish,and combined with the feeding selectivity of the Yangtze finless porpoise,there were 22 fish species with a high potential to be palatability bait for the finless porpoise. All those fishes took account for 32.3% in weight of harvest by the electric fishing and fish resource could be foraged by the finless porpoise in the Xijiang Oxbow is about 30 500-40 800 kg/year. It was suggested that the fish community should be monitored continuously to prevent the piscivorous fishes to overgrow to compete with Yangtze finless porpoise for food.
Key words：Xijiang Oxbow; hydroacoustics; Yangtze Finless Porpoise; standing crop; maximum sustainable yield