关键词: 长江江豚, 摄食, 半自然水域

Abstract: Between April 2000 and March 2002 , we observed feeding behavior of the five finless porpoises ( Neophocaena phocaenoides asiaeorientalis) in a Semi-nature Reserve of Yangtze River. Our results indicated that the porpoises required about two months to adapt to the environments of the semi-nature reserve. At the beginning of the captivity , most of their body weights were decreased by about 13.8 %. In view of the economics and edibility of their baits , common carp ( Cyprinus carpio) was considered the best , however , grass carp ( Ctenopharyngodon idellus ) and silver carp (Hypophthalmichthys molitrix) should be the first choice to be released into the semi-nature reserve. After feeding them in captivity , daily food consumption of the dolphins averaged 6.3 % of their body weight annually ; and with only 4.1 % and 9.5 %of their body weights during summer and winter months , respectively. This was 3 % less than they were kept in the pool indicating that they obtained one-third of the energy required from the reserve. Variations of feeding rates of the porpoises in the morning were significantly different from the feeding in the afternoon ( P< 0.05) . The feeding in the reserve during summer occurred at dawn or dusk while feeding during winter often appeared in the afternoon.

Key words: Finless porpoise ( Neophocaena phocaenoides asiaeorientalis), Feeding, Semi-nature reserve