title: [Effects of calcification on respiratory quotient of cultured oyster Crassostrea gigas and its fouling animals].
abstract: Respiratory quotient (RQ) is one of the basic indices in physiology and energy metabolism of animals. When RQ is calculated, the amount of released CO2 is typically used directly. But for calcifying marine organisms, calcification which can affect dissolved inorganic carbon (DIC) content in the water may cause methodological error to some extent, if it is ignored. In this paper, RQ and O/N of cultured oyster Crassostrea gigas and 3 marine fouling animal species (Mytilus edulis, Ciona intestinalis, Styela clava) were measured in the respiratory chamber to discuss the effect of calcification in RQ determination. The results demonstrated that calcification rates of C. gigas and M. edulis were (56.37 +/- 14.85) and (17.95 +/- 7.21) micromol x g(-1) x h(-1), respectively. (3.72 +/- 0.80) and (1.48 +/- 0.14) mg x L(-1) DIC in the water were correspondingly decreased, which occupied about (60.9 +/- 7.6)% and (39.9 +/- 5.7)% of respired CO2, respectively. RQ values of 4 animals were C. gigas 1.38 +0.19, M. edulis 1.18 +/- 0.11, C. intestinalis 1.11 +/- 0.05 and S. clava 1.32 +/- 0.19, which agreed with the O/N values except C. intestinalis. Meanwhile, the uncorrected RQ values of C. gigas and M. edulis were 0.56 +/- 0.19 and 0.70 +/- 0.04, respectively, which were contrary to the O/N values. Therefore, it was obviously that calcification could result in a significant influence on the respiratory quotient by affecting water DIC concentration and should be accurately calculated in RQ measurement.
authors.forename: Li-Hu
authors.initials: LH
authors.lastname: Ren
authors.forename: Ji-Hong
authors.initials: JH
authors.lastname: Zhang
authors.forename: Jian-Guang
authors.initials: JG
authors.lastname: Fang
authors.forename: Yong-Feng
authors.initials: YF
authors.lastname: Yao
authors.forename: Yi-Tao
authors.initials: YT
authors.lastname: Zhang
authors.forename: Zhen-Kun
authors.initials: ZK
authors.lastname: Gao
authors.forename: Ming-Liang
authors.initials: ML
authors.lastname: Zhang
mesh_terms: D000818:Animals; D059001:Aquatic Organisms; D002244:Carbon / Q000032:analysis*; D002938:Ciona intestinalis; D049896:Crassostrea / Q000502:physiology*; D004734:Energy Metabolism; D049880:Mytilus edulis; D014561:Urochordata; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D002244:Carbon