Monitoring of metabolic responses of intact Haliotis (abalones) under salinity stress by 31P surface probe localized NMR

Abstract

Surface probe localized ³¹P NMR spectroscopy was employed to record the metabolic responses of the foot of intact Haliotis cracherodii and H. rufescens (black and red abalones) under hyper- and hypoosmotic stresses. Use of the surface probe allowed spectral localization on the foot of intact abalones, facilitated monitoring of different sizes of animals, and minimized constraints on aquatic chamber design normally imposed by homogeneous-field probes. Generally, hyperosmotic stress (51‰) elicited more rapid changes of phosphate metabolites than hypoosmotic stress (17‰). As with the well-studied hypoxic stress in intact mammalian and excised molluscan tissue, both salinity treatments caused drops in the phosphagen and increases in inorganic phosphate levels. However, osmotic stress was distinct from hypoxic stress inthat intracellular pH did not change and nucleotide triphosphate (NTP) concentrations dropped immediately. Although these findings are preliminary, they demonstrate the utility of the surface probe approach for studies of environmental stress in intact marine invertebrates.