Handa Takeshi
Effect of air exposure on the oxygen and acid-base status of hemolymph in the noble scallop Mimachlamys nobilis
Journal of National Fisheries University Volume 70 Issue 3
Page 69-77
published_at 2022-01
Title
ヒオウギガイのヘモリンパ液の酸塩基平衡に及ぼす大気曝露の影響
Effect of air exposure on the oxygen and acid-base status of hemolymph in the noble scallop Mimachlamys nobilis
Abstract
We investigated the oxygen and acid–base status of the noble scallop Mimachlamys nobilis during air exposure for 24 h. The hemolymph of noble scallop was collected from the adductor muscle, and O_2 partial pressure (Po_2), pH, CO_2 partial pressure (Pco_2), and bicarbonate ion concentration ([HCO_3^–]) were examined during air exposure. Hemolymph Po_2 decreased from 69.5 torr (mean value) to 46.3 torr during air exposure for 6 h, and reached to 19.0 torr after 24 h. The hemolymph Po_2 of air-exposed noble scallops decreased gradually and caused progressive hypoxemia by hypoventilation of the ctenidium. Air-exposed noble scallops showed a reduction in pH and elevation of Pco_2 and [HCO_3^–] of the hemolymph. In air-exposed noble scallops, the hemolymph pH decreased from 7.460 to 7.045 at 6 h and to 6.348 at 24 h. The hemolymph Pco_2 increased from 1.30 torr to 5.05 torr at 6 h and to 56.6 torr at 24 h during air exposure. The [HCO_3^–] increased from 1.26 mM/L to 1.88 mM/L at 6 h and to 4.19 mM/L at 24 h. N32From these results, in the first 6 h of air exposure, noble scallops mainly underwent respiratory acidosis by excess accumulation of CO_2 due to hypoventilation. Meanwhile, after 24 h of air exposure, noble scallops showed mainly metabolic acidosis partially compensated by mobilized [HCO_3^–] from the shell.
Source Identifiers
[PISSN] 0370-9361
Creator Keywords
Mimachlamys nobilis
noble scallop
hemolymph
acid-base balance
air exposure
respiratory physiology
Languages
eng
Resource Type
departmental bulletin paper
Publishers
National Fisheries University
Date Issued
2022-01
File Version
Version of Record
Access Rights
open access
Relations
[ISSN]0370-9361