Yuan Xi

EFFECTS OF FLOW RATE ON SWIMMING BEHAVIOR AND ENERGY CONSUMPTION OF SCHIZOTHORAX CHONGI

The aims of the present experiment were to gain the motion regular patterns,the physical activity level,the rules of metabolic energy requirements and the lowest oxygen consumption of Schizothorax chongi(Cyprinida,Schizothoracinae).The flow rate was the main condition considered,and it was one of the major factors of the river environment.In the experiment,effects of flow rate on swimming behavior and energy consumption of Schizothorax chongi had been tested in a special sealed experimental device.The results suggested that the tail beat frequencies(TBF) of Schizothorax chongi increased with the swimming speed.But the tail beat amplitude decreased as the swimming speed increasing.According to the results of the oxygen consumption to the swimming speed,the oxygen consumption of Schizothorax chongi increased significantly as the swimming speed increased.The protocol of the critical swimming speed was carried out at 1BL interval for a set time of 30min.And the result showed that,at(26±1)℃,the relative critical swimming speed of Schizothorax chongi,body length of(10.60±0.54) cm,was(11.5±0.5) BL/s,and the absolute critical swimming speed was(110.28 ±2.02) cm/s.The relative critical swimming speed was higher than other carps,which was consisted with the habitat where the Schizothorax chongi lived,and the flow rate was 0.5—1.5 m/s.The result indicated that the capability of the swimming can be trained.The relationship between oxygen consumption rate and relative swimming speed at swimming speed of 1—7 BL/s was: AMR = 93.08e(0.326V)+314.33,R2= 0.994;the relationship between cost of transport(COT) and relative swimming speed was: COT=28e(1.03V) +6.05,R2=0.998.While the swimming speed reached to 8 BL/s,the oxygen consumption rate was decreased to(978.78±189.38) mg O2/(kg.h) from the largest,(1245.57±90.97) mg O2/(kg.h),at 7 BL/s swimming speed.As the swimming speed increasing,1—7 BL/s,metabolic rate increased obviously,but the cost of transport decreased,and the lowest consumption was(6.00±1.57)J/(kg.m),at 6 BL/s,about 0.68 m/s,which was considered as the maximum efficiency swimming speed.The study of the swimming behavior and oxygen consumption of Schizothorax chongi were to obtain the basic information for the physiology and ecology behaviors of this important species,and to find effective methods to protest it in the building of the fishes passage,and the optimal scheduling of cascaded hydropower stations.