Mass Scaling Of Metabolic Rates Of Body And Organs In The Common Carp And The Triploid Carp

In this study,the common carp?Cyprinus carpio?and the triploid carp?Cyprinus carpio Xiangyunnensis?was used to study the body mass?M?scaling of resting metabolic rate?RMR?,mass-specific oxygen consumption rate of organ(MS-M_O2organ),organ mass(M_organ),and cell surface area of liver(SA_LC)and muscle(SA_MC).The RMR,MS-M_O2organ,SA_LC,and SA_MC were compared between the common carp and the triploid carp.The results were as follows:1.RMR of the common carp and the triploid carp scaled with M by scaling exponents of0.717 and 0.748,respectively.There were no significant differences of both b_RMR and RMR between species.2.MS-M_O2 of liver,heart,and brain of the common carp was significantly higher,but MS-M_{O2 muscle} of the common carp was lower than those of the triploid carp.MS-M_O2 of liver,heart,and brain of both two species and MS-M_{O2 muscle} of the common carp were negatively related to M,while MS-M_{O2 muscle}2 muscle of the triploid carp was not related to M.The scaling exponent b values of MS-M_O2 of liver,heart,and brain of the common carp were significantly lower than those of the triploid carp.MS-M_{O2 brain}2 brain of the common carp was significantly higher than MS-M_{O2 liver}2 liver and MS-M_{O2 muscle}.MS-M_{O2 liver} was higher than MS-M_{O2 heart} and MS-M_{O2 muscle}.MS-M_{O2 heart} was higher than MS-M_{O2 muscle}.There was no significant difference between MS-M_{O2 liver} and MS-M_{O2 brain} of the triploid carp.MS-M_{O2 liver} and MS-M_{O2 brain} of the triploid carp were higher than MS-M_{O2 heart}.3.The SA_LC and SA_MCC were not related to M of the common carp.The SA_LC of the triploid carp was negatively related to M by scaling exponent of-0.092,while the SA_MC was positively related to M by scaling exponent of 0.196.The SA_LC and SA_MCC of the triploid carp were larger than the common carp,but with no significant difference in scaling exponents.4.The M_organ of each species was positively related to M.The scaling exponents of M_liveriver were0.953 and 0.889,respectively.The scaling exponents of M_hearteart were 0.894 and 0.924.The scaling exponents of M_brainrain were 0.473 and 0.523.The scaling exponents of M_muscleuscle were 1.047and 1.046.There was no significant difference of b values among M_organ.The M_liver and M_muscle of the common carp were significantly higher,but M_brainrain significantly lower than that of the triploid carp.There was no significant difference of M_heart between speciesThe conclusions of this study were as follows:1.There was no significant difference between b_RMR and RMR of two species,which supports MLB hypothesis.2.The scaling exponent b of MS-M_O2 of each organ of the common carp was significantly lower than that triploid common carp,suggesting that MS-M_{O2 organ}2 organ of the common carp fallen faster with M.There was no significant difference of b_RMR and RMR between species,suggesting that the ontogenetic change of organ oxygen consumption rate was not the main mechanism affecting metabolic scaling.3.The SA_LC and SA_MCC of the triploid carp were larger than those of the common carp,which supports the law that size of a triploid cell is greater than that of a diploid cell.4.The SA_LC and SA_MC of the common carp did not change with M,while b_RMR was less than1;on the other hand,the SA_LC decreased and SA_MC increased with M of the triploid carp,which was not consistent with the predictions of the CM hypothesis.It suggests that in addition to the effect of cell size,the difference of b_RMR may also be caused by the decrease in cellular metabolism.5.The ratio of the metabolically active organs,including liver,heart,and brain mass,to the body mass decreased with increasing M.On the contrary,the ratio of non-active muscles to the body mass increased with increasing M,but the degree of increase was too small to explain the scaling exponent of RMR.The results only partially support the organ size hypothesis.6.There was no significant difference in b_RMR or RMR between two species,and the results were inconsistent with the prediction of the exchange area-metabolic demand constraints hypothesis.The metabolic levels of the active organs of the both species decreased with increasing M,but decreased significantly faster in the common carp and may have a negative effect on b_RMR.Therefore,in addition to the limitations of exchange areas of cells,the effects of metabolic levels of cells on the scaling exponent should also be considered.