安静状態のイガイMytilus coruscus酸塩基平衡におけるヘモリンパ液の二酸化炭素分圧と重炭酸イオン濃度

The hemolymph CO_2 partial pressure and bicarbonate concentration of the acid-base balance of Mytilus coruscus under resting conditions

We investigated the hemolymph CO_2 partial pressure (Pco_2) and bicarbonate concentration ([HCO_3^–]) of the acid–base balance of Mytilus coruscus under resting conditions. Hemolymph collected from the adductor muscle was subjected to the following measurements. Mean values for hemolymph pH and total CO_2 concentration for this state between 18℃ and 23℃ were 7.568-7.601 and 1.54-1.59 mM/L, respectively. Hemolymph Pco_2 and [HCO_3^–] were calculated using the hemolymph pKapp estimated using the relational expression with temperature. Hemolymph Pco_2 and [HCO_3^–] were 1.77-1.83 torr and 1.47-1.50 mM/L at 18℃ and 23℃. To verify Pco_2 and [HCO_3^–], the values were calculated using pKapp obtained by in vitro method (tonometry). Despite the different determination methods, no statistical difference in the obtained values of Pco_2 and [HCO_3^–] were observed. Non-bicarbonate buffer values (ꞵ_NB), which were calculated using the slope of the relational expression between pH and [HCO_3^–] in hemolymph, were 0.42 slykes at 18℃, and 0.54 slykes at 23℃. The hemolymph ꞵ_NB of M. coruscus was in the range of other bivalves, and the hemolymph buffer capacity of the non-bicarbonate buffer system would reflect the Mitilid species.

Creators Handa Takeshi

Creators Araki Akira

[ISSN]0370-9361