Effects Of Body Mass On Metabolic Capacity Of Coreius Guichenoti

To study the effects of body mass on metabolic capacity, the energy store and metabolic regulation mechanisms during migratory preparation period in fish, four set of experiments were conducted in C. guichenoti. In chemical compositions set,65specimens of C. guichenoti were divided into6groups. Body chemical compositions were measured and energy density was estimated. In resting set, resting metabolic rate (RMR), hematological parameters, citrate synthase (CS) activity and lactate dehydrogenase (LDH) activity in liver, red muscle, white muscle were measured. In activity set, RMR, maximum metabolic rate (MMR), absolute scope (AS), EPOC, hematological parameters, CS activity and LDH activity in liver, red muscle, white muscle were measured. In recovery set lactic acid, glycogen and glucose levels in blood, liver, red muscle, white muscle were measured at rest (resting controls) and during different recovery periods (0,0.5,1,2,4,8,16h) after exhaustive exercise.The results are as follows:1. The contents of water (WAT) and ash (ASH) decreased and the contents of lipid (FAT), protein (PRO) and energy density (E) increased with the increase in body mass, there were significantly correlation between body mass and FAT, PRO, E (P<0.05), the slope were0.042,0.0035,0.017respectively. The contents of lipid (FAT) and energy density (E) were negatively related to the contents of water (WAT), the relationships between FAT or E and WAT could be described as: FAT=-1.14WAT+91.44(r2=0.970, P<0.05, n=65); E=-0.44WAT+38.80(r2=0.986, P<0.05, n=65).2. Resting metabolic rate (RMR) increased with the increase in body mass, values of the scaling were0.822in resting set and0.728in activity set. Maximum metabolic rate (MMR), absolute scope (AS) and EPOC were increased and metabolic scope (MS) was no significant change with the increase in body mass, there were significant positive correlation between body mass and MMR, AS and EPOC (P<0.05), the values of scaling were0.732,0.725and1.00respectively.3. The content of hemoglobin (Hb) also increased but RBC and size of red blood cells were no significant change with the increase in body mass. There were significantly correlation between Hb with standard body mass (Hbs) and RMR with standard body mass (RMRS) and MS (P<0.05).4. CS activity and LDH activity in liver and red muscle, CS activity in white muscle were no significant change, LDH activity in white muscle was significantly increased (P<0.05) with the increase in body mass. The content of lactate (LD) in blood, liver, red muscle and white muscle were0.33-0.84mg·ml-1,3.71-5.94mg·g-1,1.30-1.87mg·g-1and0.48-0.65mg·g-1respectively in lager body mass group. LD in liver, red muscle and white muscle were3.58-4.79mg-g·-1.1.34-1.46mg·g-1and0.30-0.41mg·g-1respectively in smaller body mass group. LD were all showed for the first rise rapidly and then slowly decreased to the initial level, Gly were all showed for the first decreased and then increased to the initial level, the peaks and changes of LD in lager body mass group were higher than the group with smaller body mass.The conclusions are as follows1. In this study FAT was1.97-27.22%which higher than most other fish and the accumulation rate is higher than the accumulation rate of PRO. Lipid is the main metabolic substrate in the process of migratory movement, suggesting that the high and rapid accumulation rate of the FAT in C. guichenoti is related to their migratory habits.2. MS was no significant change and EPOC was increased with the increase in body mass indicating that individual-level anaerobic capacity was significantly enhanced but individual-level aerobic capacity was no significantly enhanced with individual growth in C. guichenoti.3. Hb increased with the increase in body mass indicating the capacity of transport oxygen enhanced. Hbs was positive related to MS indicating the capacity of transport oxygen affect aerobic capacity.3. LDH activity in white muscle was significantly increased and the peaks and change rate of LD in lager body mass group were higher than the group with smaller body mass after exhaustive exercise indicating that anaerobic capacity increased with individual growth in C. guichenoti.