In situ determination on food consumption and ecological conversion efficiency of a marine fish species, Hyporhamphus sajori

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·d) (wet weight); (3) the daily food consumption tended to change in irregular waving form, with average value being (10.16×l0~(-2)±1.19×l0~(-2) g/ (g·d) (wet weight) or (55.56 × 10~(-2) ±6.51 × 10~(-2) kJ/

In situ determination on food consumption and ecological conversion efficiency of a marine fish species, Hyporhamphus sajori

-- The food consumption and ecological conversion efficiency of a species marine pelagic and small 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 St = a@ e- b@t. There was not significant difference of instantaneous gastric evacuation rate between two determinations, with average value being 0.13 × 10- 2g/ (g@h) (wet weight); (3) the daily food consumption tended to change in irregular waving form, with average value being (10.16 × 10-2 ± 1.19 × 10-2) 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× 10-2g/ (g@d) (wet weight) or 12.91 ×10-2kJ/ (g@d), from which 31.89% (wet weight) or 23.24% kJ of ecological conversion efficiency could be obtained.