Effects of artificial submersed vegetation on consumption and growth of mandarin fish Siniperca chuatsi (Basilewsky) foraging on live prey

摘要

Mandarin fish Siniperca chuatsi (Basilewsky) is a commercially important aquaculture species, mainly cultured in Chinese ponds and only fed live fish. We evaluated the effects of artificial vegetation on consumption and growth of mandarin fish foraging on live prey Cirrhinus mrigala (Hamilton) in outdoor pools. In comparison to the 0% vegetation treatment, mandarin fish captured more prey in all treatments where vegetation was added. However, prey consumption did not vary between 15, 30, 45 and 60% vegetation additions. Weight gain of mandarin fish in the 0% vegetation treatment was significantly lower than those in the four vegetated treatments, with the highest weight gain recorded for the 30% vegetation treatment. Similar differences in specific growth rate were observed. The specific growth rate increased with increased vegetation coverage, but then declined slowly as vegetation coverage continued to increase, with a peak in the 30% vegetation treatment. These results suggest that transplanting submerged vegetation into culture ponds in an effort to improve water quality would not affect or even improve prey consumption and growth of mandarin fish, and that suitable vegetation coverage would range between 30% and 60% in terms of growth rate.