In vivo 31 P-MRS of muscle bioenergetics in marine invertebrates:Future ocean limits scallops' performance

• Published in: Magnetic Resonance Imaging
• Main Authors: Bock, Christian, Wermter, Felizitas C., Schalkhausser, Burgel, Blicher, Martin E., Pörtner, Hans O., Lannig, Gisela, Sejr, Mikael K.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2019
• Subjects: Aerobic power budget; Bivalves; Chemical shift imaging (CSI); Energy metabolism; pH; Phosphagen; Arctic; Climate change
• Online Access: https://pure.au.dk/portal/en/publications/ba961eea-8922-4359-a2d6-12f4dd0badf8; https://doi.org/10.1016/j.mri.2019.06.003; http://www.scopus.com/inward/record.url?scp=85066986596&partnerID=8YFLogxK

Object: Dynamic in vivo 31 P-NMR spectroscopy in combination with Magnetic Resonance Imaging (MRI) was used to study muscle bioenergetics of boreal and Arctic scallops (Pecten maximus and Chlamys islandica) to test the hypothesis that future Ocean Warming and Acidification (OWA) will impair the performance of marine invertebrates. Materials & methods: Experiments were conducted following the recommendations for studies of muscle bioenergetics in vertebrates. Animals were long-term incubated under different environmental conditions: controls at 0 °C for C. islandica and 15 °C for P. maximus under ambient PCO 2 of 0.039 kPa, a warm exposure with +5 °C (5 °C and 20 °C, respectively) under ambient PCO 2 (OW group), and a combined exposure to warmed acidified conditions (5 °C and 20 °C, 0.112 kPa PCO 2 , OWA group). Scallops were placed in a 4.7 T MR animal scanner and the energetic status of the adductor muscle was determined under resting conditions using in vivo 31 P-NMR spectroscopy. The surplus oxidative flux (Q max ) was quantified by recording the recovery of arginine phosphate (PLA) directly after moderate swimming exercise of the scallops. Results: Measurements led to reproducible results within each experimental group. Under projected future conditions resting PLA levels (PLA rest ) were reduced, indicating reduced energy reserves in warming exposed scallops per se. In comparison to vertebrate muscle tissue surplus Q max of scallop muscle was about one order of magnitude lower. This can be explained by lower mitochondrial contents and capacities in invertebrate than vertebrate muscle tissue. Warm exposed scallops showed a slower recovery rate of PLA levels (k PLA ) and a reduced surplus Q max . Elevated PCO 2 did not affected PLA recovery further. Conclusion: Dynamic in vivo 31 P-NMR spectroscopy revealed constrained residual aerobic power budgets in boreal and Arctic scallops under projected ocean warming and acidification indicating that scallops are susceptible to future climate change. The observed ...