Estimation of CO_2 partial pressure and bicarbonate concentration in the hemolymph of the black-lip pearl oyster Pinctada margaritifera

クロチョウガイのヘモリンパ液における二酸化炭素分圧と炭酸水素イオン濃度の算出

Estimation of CO_2 partial pressure and bicarbonate concentration in the hemolymph of the black-lip pearl oyster Pinctada margaritifera

Creators Handa Takeshi

Creators Yamamoto Ken-ichi

We examined hemolymph pH, total CO_2 content（Tco_2, mM/l), CO_2 partial pressure（Pco_2, mmHg）and bicarbonate concentration（[HCO_3^-], mM/l) in order to evaluate the acid-base balance of the black-lip pearl oyster Pinctada margaritifera under normoxic conditions. Hemolymph was collected anaerobically through a cannula after catheterization of the adductor muscle. The mean values of the hemolymph pH and Tco_2 were 7.563 and 2.04 mM/l, respectively. Using the CO_2 solubility coefficient and apparent dissociation constant of carbonic acid determined in this study, Pco_2 and [HCO_3^-] were calculated as 1.50 mmHg and 1.98 mM/l, respectively. These values were in same range as those of the hemolymph of the akoya pearl oyster P. fucata.

[ISSN]0370-9361