The food consumption and ecological conversion efficiency of a species marine pelagic andsmall size fish, Hyporhamphus sajori, were determined by using in situ stomach content method presented by Eggers. The results s...The food consumption and ecological conversion efficiency of a species marine pelagic andsmall size fish, Hyporhamphus sajori, were determined by using in situ stomach content method presented by Eggers. The results showed that: (1) the fish was taken in food all day, so empty-stomach rate was very low, taking up about 4.5% of the total determined fish number. However, the fish still has significant daily feeding rhythm. A feeding peak was found 0:00 o'clock at night, but feeding level was always high in the daytime; (2) relationship between instantaneous food content in stomach and corresponding time could be described as S_t = a · e (-b·t). There was not significant difference of instantaneous gastric evacuation rate between two determinations, with average value being 0.13 × 10^(-2) g/ (g' h) (wet weight); (3) the daily food consumption tended to change in irregular waving form, with average value being (10.16Xl0^(-2)±1.19xl0(-2) g/ (g·d) (wet weight) or (55.56 × 10(-2) ±6.51 × 10^(-2) kJ/ (g·d). The wave distance is constant and about 14 d, but the wave height changed largely; (4) actual determining value of daily growth rate was 3.24 × 10^(-2)g/ (g·d) (wet weight) or 12.91 × 10^(-2)kJ/ (g·d), from which 31.89% (wet weight) or 23.24% kJ of ecological conversion efficiency could be obtained.展开更多
基金This study was supported by the DevelopmentProgramming Program of National Major Basic Research of China un- der contract No.G19990437.
文摘The food consumption and ecological conversion efficiency of a species marine pelagic andsmall size fish, Hyporhamphus sajori, were determined by using in situ stomach content method presented by Eggers. The results showed that: (1) the fish was taken in food all day, so empty-stomach rate was very low, taking up about 4.5% of the total determined fish number. However, the fish still has significant daily feeding rhythm. A feeding peak was found 0:00 o'clock at night, but feeding level was always high in the daytime; (2) relationship between instantaneous food content in stomach and corresponding time could be described as S_t = a · e (-b·t). There was not significant difference of instantaneous gastric evacuation rate between two determinations, with average value being 0.13 × 10^(-2) g/ (g' h) (wet weight); (3) the daily food consumption tended to change in irregular waving form, with average value being (10.16Xl0^(-2)±1.19xl0(-2) g/ (g·d) (wet weight) or (55.56 × 10(-2) ±6.51 × 10^(-2) kJ/ (g·d). The wave distance is constant and about 14 d, but the wave height changed largely; (4) actual determining value of daily growth rate was 3.24 × 10^(-2)g/ (g·d) (wet weight) or 12.91 × 10^(-2)kJ/ (g·d), from which 31.89% (wet weight) or 23.24% kJ of ecological conversion efficiency could be obtained.
