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Seo E, Seo Y. Pulsative venous return from the branchial vessels to the heart of the bivalve Mytilus galloprovincialis supports the constant-volume mechanism. J Exp Biol 2024; 227:jeb247345. [PMID: 38644758 DOI: 10.1242/jeb.247345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Accepted: 04/08/2024] [Indexed: 04/23/2024]
Abstract
In bivalves and gastropods, ventricle contraction causes a negative pressure in the auricles and increases venous return from the afferent oblique vein (AOV): the constant-volume (CV) mechanism. The flow in the AOV should be a pulsative flow synchronized with the ventricular contraction. The flow in the heart and adjacent vessels of Mytilus galloprovincialis were measured by magnetic resonance imaging to confirm this hypothesis. Under a regular heartbeat, pulsative flows in the AOV and branchial vessels (BVs) were almost completely synchronized with the flow in the aorta, while filling of the ventricle was in the opposite phase. Flows in the BVs were directed to the posterior direction, and a pair of BVs in the gill axes (the efferent BVs) were connected to the AOV. Based on the images of the whole pathway of the AOV in an oblique slice, we confirmed that haemolymph flow was evoked from the efferent BVs and flow into the ventricle via the auricle was completed in a single heartbeat. Therefore, the walls of the AOV and BVs could resist negative transmural pressure caused by the ventricular contraction. In conclusion, the auricle, the AOV and the BVs, including the gill filaments, act as a suction pump. The pulsative venous return is driven by the negative pressure of the AOV as in the CV mechanism, and the negative pressure in the efferent BVs could draw haemolymph from the sinus via the gill and the afferent BVs. Therefore, Mytilus can start and stop its heartbeat as necessary.
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Affiliation(s)
- Eriko Seo
- Central Laboratory, Marine Ecology Research Institute, Onjuku, Chiba 299-5105, Japan
| | - Yoshiteru Seo
- Division of Cell Structure, National Institute for Physiological Sciences, Okazaki, Aichi 444-8787, Japan
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Seo E, Ohishi K, Imaizumi-Ohashi Y, Yokoi-Hayakawa M, Yamaguchi T, Seo Y. Foot extension and retraction in the clam Calyptogena okutanii without any Keber's valve: an inflatable fastener bag model. J Exp Biol 2023; 226:285913. [PMID: 36484122 DOI: 10.1242/jeb.244857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022]
Abstract
In order to investigate the foot manipulation of a clam without a Keber's valve, Calyptogena okutanii was examined by light microscopy, magnetic resonance imaging and computed tomography. The foot chamber was divided into two compartments by a dense muscle fastener zone (FZ) comprising a pedal artery and sinuses in the mid-sagittal plane in between muscles running in the anterior-posterior oblique direction. The distal part of the foot chamber (inflatable fastener bag, IFB) had a loose superficial muscle layer. The proximal part of the foot chamber (visceral reservoir, VR) was covered by a dense superficial muscle layer. The outlet of the VR was connected with the hinge ligament duct, consisting of the hinge ligament, a pair of shells and the pericardium. Based on these anatomical structures, foot extension starts from contraction of muscles in the FZ, so that flow in the FZ is stopped. Then, the superficial muscles of the foot contract, and the pressure of the IFB increases so that the foot can extend. Foot retraction starts from the relaxation of muscles in the FZ so that the hemolymph returns to the VR. The hinge ligament duct allows a constant return flow from the foot chamber to the gills and the heart. The heart rate and the flow in the FZ, which decreased and increased during the foot extension and retraction, respectively, supported this model. In conclusion, the FZ of Calyptogena okutanii could be an alternative to Keber's valve in Anodonta, playing a similar role.
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Affiliation(s)
- Eriko Seo
- Central Laboratory, Marine Ecology Research Institute, Onjuku, Chiba 299-5105, Japan
| | - Kazue Ohishi
- Japan Agency for Marine-Earth Science and Technology, Yokosuka, Kanagawa 237-0061, Japan
| | - Yoshie Imaizumi-Ohashi
- Research Center for Advanced Medical Science, Dokkyo Medical University School of Medicine, Mibu, Tochigi 321-0293, Japan
| | - Mika Yokoi-Hayakawa
- Research Center for Advanced Medical Science, Dokkyo Medical University School of Medicine, Mibu, Tochigi 321-0293, Japan
| | - Tsuyoshi Yamaguchi
- Department of Anatomy, Dokkyo Medical University School of Medicine, Mibu, Tochigi 321-0293, Japan
| | - Yoshiteru Seo
- Division of Cell Structure, National Institute for Physiological Sciences, Okazaki, Aichi 444-8787, Japan
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Pérez-Cebrecos M, Prieto D, Blanco-Rayón E, Izagirre U, Ibarrola I. Differential tissue development compromising the growth rate and physiological performances of mussel. MARINE ENVIRONMENTAL RESEARCH 2022; 180:105725. [PMID: 35987041 DOI: 10.1016/j.marenvres.2022.105725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 07/27/2022] [Accepted: 08/04/2022] [Indexed: 06/15/2023]
Abstract
Differences in the food acquisition rates and in the energetic costs of metabolism seem to affect the growth rate variability of mussels. The aim of this study was to analyze if the physiological performances responsible for such growth rate variability are accompanied by structural differences at tissue or cellular level in the main organs involved in energy acquisition (gill) and processing (digestive gland). Fast growers had higher cilia density and metabolic efficiency in their gill, and well-developed digestive tissue with barely no connective tissue or atrophy. Slow-growing mussels displayed stress signs that impede the proper acquisition, digestion and absorption of food: low cilia density, low mitochondrial capacity and high antioxidant activity levels in the gills, and high atrophy of the digestive gland. The data herein explains the growth rate variability of mussels, demonstrating that morphological and functional differences exist between fast and slow growers.
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Affiliation(s)
- Maitane Pérez-Cebrecos
- Department of Genetics, Physical Anthropology and Animal Physiology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Leioa, Spain; Research Centre for Experimental Marine Biology and Biotechnology (PiE - UPV/EHU), University of the Basque Country (UPV/EHU), Plentzia, Spain.
| | - Daniel Prieto
- Department of Genetics, Physical Anthropology and Animal Physiology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Esther Blanco-Rayón
- Research Centre for Experimental Marine Biology and Biotechnology (PiE - UPV/EHU), University of the Basque Country (UPV/EHU), Plentzia, Spain; CBET Research Group, Department of Zoology and Animal Cell Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Urtzi Izagirre
- Research Centre for Experimental Marine Biology and Biotechnology (PiE - UPV/EHU), University of the Basque Country (UPV/EHU), Plentzia, Spain; CBET Research Group, Department of Zoology and Animal Cell Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Irrintzi Ibarrola
- Department of Genetics, Physical Anthropology and Animal Physiology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Leioa, Spain
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Bakhmet I, Ekimov D. Application of a Novel Computer-Aided System to Monitor Cardiac Activity in a Mussel Undergoing Starfish Predation. THE BIOLOGICAL BULLETIN 2021; 240:200-204. [PMID: 34129441 DOI: 10.1086/714361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
AbstractWe explored a modified, computer-aided monitoring system for continuous, long-term recording of Bivalvia cardiac activity. To estimate the capabilities of this system, we used it to monitor the cardiac activity of a mussel (Mytilus edulis) under predation threat from a starfish (Asterias rubens). In addition, we used a web camera to track the behavioral responses of these animals. Compared to its state during normal feeding activity, the mussel's heart rate showed no significant changes when the mussel was near the starfish. However, when the mussel was attacked by the starfish, its heart rate and contraction power (i.e., amplitude) increased and subsequently decreased down to the absence of any heartbeats within 2.5 hours. The results obtained in this study proved the usefulness of this new system as a stress-monitoring tool.
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Eggermont M, Cornillie P, Dierick M, Adriaens D, Nevejan N, Bossier P, Van den Broeck W, Sorgeloos P, Defoirdt T, Declercq AM. The blue mussel inside: 3D visualization and description of the vascular-related anatomy of Mytilus edulis to unravel hemolymph extraction. Sci Rep 2020; 10:6773. [PMID: 32317671 PMCID: PMC7174403 DOI: 10.1038/s41598-020-62933-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 03/19/2020] [Indexed: 12/28/2022] Open
Abstract
The blue mussel Mytilus edulis is an intensely studied bivalve in biomonitoring programs worldwide. The lack of detailed descriptions of hemolymph-withdrawal protocols, particularly with regard to the place from where hemolymph could be perfused from, raises questions regarding the exact composition of aspirated hemolymph and does not exclude the possibility of contamination with other body-fluids. This study demonstrates the use of high resolution X-ray computed tomography and histology combined with 3D-reconstruction using AMIRA-software to visualize some important vascular-related anatomic structures of Mytilus edulis. Based on these images, different hemolymph extraction sites used in bivalve research were visualized and described, leading to new insights into hemolymph collection. Results show that hemolymph withdrawn from the posterior adductor muscle could be extracted from small spaces and fissures between the muscle fibers that are connected to at least one hemolymph supplying artery, more specifically the left posterior gastro-intestinal artery. Furthermore, 3D-reconstructions indicate that puncturing hemolymph from the pericard, anterior aorta, atria and ventricle in a non-invasive way should be possible. Hemolymph withdrawal from the heart is less straightforward and more prone to contamination from the pallial cavity. This study resulted simultaneously in a detailed description and visualization of the vascular-related anatomy of Mytilus edulis.
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Affiliation(s)
- Mieke Eggermont
- Laboratory of Aquaculture and Artemia Reference Center, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Pieter Cornillie
- Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - Manuel Dierick
- Centre for X-ray Tomography (UGCT), Department Physics and Astronomy, Proeftuinstraat 86/N12, 9000, Gent, Belgium
- XRE nv. Bollebergen 2B box 1, 9052, Ghent, Belgium
| | - Dominique Adriaens
- Research Group Evolutionary Morphology of Vertebrates, Ghent University, K.L. Ledeganckstraat 35, 9000, Ghent, Belgium
| | - Nancy Nevejan
- Laboratory of Aquaculture and Artemia Reference Center, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Peter Bossier
- Laboratory of Aquaculture and Artemia Reference Center, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Wim Van den Broeck
- Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - Patrick Sorgeloos
- Laboratory of Aquaculture and Artemia Reference Center, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Tom Defoirdt
- Laboratory of Aquaculture and Artemia Reference Center, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Annelies Maria Declercq
- Laboratory of Aquaculture and Artemia Reference Center, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium.
- Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium.
- Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium.
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Wakashin H, Seo E, Seo Y. Size-selective filtration of the atrial wall estimated from the accumulation of tracers in the kidney of the mussel Mytilus galloprovincialis. ACTA ACUST UNITED AC 2019; 222:jeb.209171. [PMID: 31548287 DOI: 10.1242/jeb.209171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 09/17/2019] [Indexed: 11/20/2022]
Abstract
In order to determine the molecular weight cut-off (MWCO) for the atrial wall filtration into kidneys of the Mytilus galloprovincialis, we employed five magnetic resonance (MR) tracers: manganese chloride (Mn2+), gadolinium chloride (Gd3+), manganese-ethylenediaminetetraacetic acid (MnEDTA), gadolinium-diethylenetriamine pentaacetic acid (GdDTPA) and oligomer-based contrast agent (CH3-DTPA-Gd). After injection of the MR tracers (1 or 2 mmol l-1×0.1 ml) into the visceral mass, T 1-weighted MR imaging (T 1w-MRI) and the longitudinal relaxation rates (1/T 1=R 1) were measured at 20°C. The MR tracers were distributed uniformly in the visceral mass within 1 h after injection. The T 1w-MRI intensity and R 1 of the kidney (R 1K) were increased by Mn2+ and MnEDTA, with urine concentrations estimated at 210 and 65 µmol l-1, respectively. The rest of the tracers showed only minimal or no increase. When the mussels were additionally incubated in seawater with 10 µmol l-1 MnCl2, R 1K was increased in the GdDTPA group, but not in the GdCl3 group. Therefore, Gd3+ might have inhibited renal accumulation of Mn2+ and Gd3+ Incubation in seawater with 10 µmol l-1 MnEDTA showed no increase in the R 1K, but additional incubation with 10 µmol l-1 MnCl2 caused an increase in R 1K It is suggested that injected MnEDTA was filtrated as MnEDTA per se, and not likely separated into free Mn2+ Thus, we concluded that the MWCO of the atrial wall of the M. galloprovincialis is around 0.5 kDa, which is almost 1/100 of that for vertebrate animals, and suggests a reduction in efforts to reabsorb metabolites and osmolytes from the urine.
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Affiliation(s)
- Hidefumi Wakashin
- Department of Regulatory Physiology, Dokkyo Medical University School of Medicine, Tochigi 321-0293, Japan
| | - Eriko Seo
- Department of Marine Ecosystem Dynamics, Division of Marine Life Science, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa 277-8564, Japan
| | - Yoshiteru Seo
- Department of Regulatory Physiology, Dokkyo Medical University School of Medicine, Tochigi 321-0293, Japan
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Seo E, Seo Y. Roles of Keber's valve and foot chamber for foot manipulation in the mussel Nodularia douglasiae. Biol Open 2019; 8:bio.039859. [PMID: 30530808 PMCID: PMC6361212 DOI: 10.1242/bio.039859] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In order to analyse the roles of Keber's valve for foot manipulation in the mussel Nodularia douglasiae, the anatomy and haemolymph flow in the cardiovascular system were detected by magnetic resonance imaging. The superficial layer of the foot was covered by a dense muscle layer, which extended to the dorsal side and connected with the shell. This closed space, the foot chamber, had an inlet (anterior aorta) and an outlet (Keber's valve). At rest, in the beginning of the systolic phase, flows in the anterior aorta and the pedal artery increased, followed by the pedal and visceral sinuses. Then these flows ceased at the end of the systolic phase, followed by inflow to the ventricle in the diastolic phase; therefore, the compliance of the foot chamber is low enough to transfer pressure pulses to the visceral sinus. Extension of the foot started with relaxation of the foot muscle, so the compliance of the foot chamber increased. Then, Keber's valve closed so that the haemolymph filled the foot haemocoel. Retraction of the foot is initiated by the opening of Keber's valve. Judging from these results Keber's valve and the foot chamber are essential for circulation at rest, foot extension and retraction.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Eriko Seo
- Department of Marine Ecosystem Dynamics, Division of Marine Life Science, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, 277-8564, Japan
| | - Yoshiteru Seo
- Department of Regulatory Physiology, Dokkyo Medical University School of Medicine, Tochigi, 321-0293, Japan
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Wakashin H, Seo E, Seo Y. Accumulation and excretion of manganese ion in the kidney of M ytilus galloprovincialis. ACTA ACUST UNITED AC 2018; 221:jeb.185439. [PMID: 30065036 DOI: 10.1242/jeb.185439] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 07/23/2018] [Indexed: 01/28/2023]
Abstract
T 1-weighted magnetic resonance imaging (T 1w-MRI) was employed to detect the accumulation of manganese ion (Mn2+) in urine in the kidney of the mussel Mytilus galloprovincialis, and the longitudinal relaxation rates (1/T 1=R 1) were measured. When the mussel was exposed to seawater containing 10 µmol l-1 Mn2+, the T 1w-MRI intensity and R 1 of the kidney, stomach and digestive glands were increased. Mn2+ might be taken into the hemolymph via the gastrointestinal tract, and then filtrated into the pericardium via the auricles. Although the image intensity in the pericardium was not affected by manganese, an image intensity enhancement was observed in the distal part of the renopericardial communication canals between the pericardium and the kidneys, indicating Mn2+ was concentrated in the excretion pathway. As the seawater Mn2+ concentration ([Mn2+]SW) was increased from 3 to 50 µmol l-1, R 1 of the kidney (R 1K) was elevated. When the mussels were immersed in 3-10 µmol l-1 [Mn2+]SW for 24 h, the Mn2+ concentration in the kidney ([Mn2+]K) showed a 15-fold increase compared with the ambient [Mn2+]SW In the range of [Mn2+]SW from 10 to 50 µmol l-1, R 1K reached a plateau level that corresponded to 200 µmol l-1 [Mn2+]K As [Mn2+]K fell transiently, voluntary excretion of urine from the kidney was assumed. The decreases in intensity were not synchronized between the right and left kidneys, and the closure of the shells might not be essential for urinary excretion. The voluntary excretion suggested an additional explanation for the large range in metal concentratons in the kidneys of the mussel.
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Affiliation(s)
- Hidefumi Wakashin
- Department of Regulatory Physiology, Dokkyo Medical University School of Medicine, Tochigi 321-0293, Japan
| | - Eriko Seo
- Department of Marine Ecosystem Dynamics, Division of Marine Life Science, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa 277-8564, Japan
| | - Yoshiteru Seo
- Department of Regulatory Physiology, Dokkyo Medical University School of Medicine, Tochigi 321-0293, Japan
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Sukhotin A, Fokina N, Ruokolainen T, Bock C, Pörtner HO, Lannig G. Does the membrane pacemaker theory of metabolism explain the size dependence of metabolic rate in marine mussels? J Exp Biol 2017; 220:1423-1434. [DOI: 10.1242/jeb.147108] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 01/28/2017] [Indexed: 01/26/2023]
Abstract
According to the Membrane Pacemaker Theory of metabolism (MPT) allometric scaling of metabolic rate in animals is determined by the composition of cellular and mitochondrial membranes that changes with body size in a predictable manner. MPT has been elaborated from interspecific comparisons in mammals. It projects that the degree of unsaturation of membrane phospholipids decreases in larger organisms, thereby lowering ion permeability of the membranes and making cellular and thus whole animal metabolism more efficient. Here we tested the applicability of the MPT to a marine ectotherm, the mussel Mytilus edulis at the intraspecific level. We determined effects of body mass on whole organism, tissue and cellular oxygen consumption rates, on heart rate, metabolic enzyme activities and on the lipid composition of membranes. In line with allometric patterns the organismal functions and processes such as heart rate, whole animal respiration rate and phospholipid contents showed a mass-dependent decline. However, the allometry of tissue and cellular respiration and activity of metabolic enzymes was poor; fatty acid unsaturation of membrane phospholipids of gill tissue was independent of animal size. It is thus conceivable that most of the metabolic allometry observed at the organismal level is determined by systemic functions. These whole organism patterns may be supported by energy savings associated with growing cell size but not by structural changes in membranes. Overall, the set of processes contributing to metabolic allometry in ectotherms may differ from that operative in mammals and birds, with a reduced involvement of the mechanisms proposed by the MPT.
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Affiliation(s)
- Alexey Sukhotin
- White Sea Biological Station, Zoological Institute of Russian Academy of Sciences, Saint-Petersburg, 199034, Russia
- Saint-Petersburg State University, Saint-Petersburg, Russia
| | - Natalia Fokina
- Institute of Biology, Karelian Research Centre of Russian Academy of Sciences, Petrozavodsk, Russia
| | - Tatiana Ruokolainen
- Institute of Biology, Karelian Research Centre of Russian Academy of Sciences, Petrozavodsk, Russia
| | - Christian Bock
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Hans-Otto Pörtner
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- University of Bremen, Bremen, Germany
| | - Gisela Lannig
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
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Seo E, Sazi T, Togawa M, Nagata O, Murakami M, Kojima S, Seo Y. A portable infrared photoplethysmograph: heartbeat of Mytilus galloprovincialis analyzed by MRI and application to Bathymodiolus septemdierum. Biol Open 2016; 5:1752-1757. [PMID: 27760729 PMCID: PMC5155536 DOI: 10.1242/bio.020909] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Infrared photoplethysmogram (IR-PPG) and magnetic resonance image (MRI) of the Mytilus galloprovincialis heart were obtained simultaneously. Heart rate was varied by changing temperature, aerial exposure and hypoxia. Higher heart rates (35-20 beat min−1) were usually observed at 20°C under the aerobic condition, and typical IR-PPG represented a single peak (peak v). The upward and downward slopes of the peak v corresponded to the filling and contracting of the ventricle, respectively. A double-peak IR-PPG was observed in a wide range of heart rates (5 to 35 beats min−1) under various conditions. The initial peak v corresponded to the filling of the ventricle, and the origin of the second peak (v’) varied with the heart rate. A flat IR-PPG with a noise-level represented cardiac arrest. Although large movement of the shells and the foot caused slow waves or a baseline drift of the IR-PPG, the heart rate can be calculated from the v-v interval. Based on these results, we assembled a portable IR-PPG recording system, and measured the heartbeats of Bathymodiolus septemdierum (Mytilidae) for 24 h on a research vessel just after sampling from the deep sea, showing that IR-PPG is a noninvasive, economical, robust method that can be used in field experiments. Summary: Infrared photoplethysmogram of Mytilus heart was analyzed by magnetic resonance imaging. Portable photoplethysmographs provide a noninvasive, economical and robust method to monitor the heartbeat of mussels in field experiments.
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Affiliation(s)
- Eriko Seo
- Department of Marine Ecosystem Dynamics, Division of Marine Life Science, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa 277-8564, Japan
| | - Toshiyuki Sazi
- Department of Molecular Physiology, National Institute for Physiological Sciences, Okazaki 444-8787, Japan
| | - Morio Togawa
- Department of Molecular Physiology, National Institute for Physiological Sciences, Okazaki 444-8787, Japan
| | - Osamu Nagata
- Department of Molecular Physiology, National Institute for Physiological Sciences, Okazaki 444-8787, Japan
| | - Masataka Murakami
- Department of Molecular Physiology, National Institute for Physiological Sciences, Okazaki 444-8787, Japan
| | - Shigeaki Kojima
- Department of Marine Ecosystem Dynamics, Division of Marine Life Science, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa 277-8564, Japan
| | - Yoshiteru Seo
- Department of Regulatory Physiology, Dokkyo Medical University School of Medicine, Tochigi 321-0293, Japan
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Uslu FE, Pekkan K. Mytilus galloprovincialis as a smart micro-pump. Biol Open 2016; 5:1493-1499. [PMID: 27612512 PMCID: PMC5087679 DOI: 10.1242/bio.021048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 09/05/2016] [Indexed: 11/19/2022] Open
Abstract
Hydrodynamic performance of the marine mussel, Mytilus galloprovincialis, is studied with time-resolved particle image velocimetry. We evaluated inhalant flow, exhalant jet flow, suction performance and flow control capabilities of the mussels quantitatively. Inhalant flow structures of mussels are measured at the coronal plane for the first time in literature. Nutrient fluid is convected into the mussel by three-dimensional sink flow. Inhalant velocity reaches its highest magnitude inside the mussel mantle while it is accelerating outward from the mussels. We calculated pressure gradient at the coronal plane. As inhalant flow approaches the mussel shell tip, suction force generated by the inhalant flow increases and becomes significant at the shell tip. Likewise, exhalant jet flow regimes were studied for 17 mussels. Mussels can control their exhalant jet flow structure from a single potential core region to double potential core region or vice versa. Peak exhalant jet velocity generated by the mussels changes between 2.77 cm s-1 and 11.1 cm s-1 as a function of mussel cavity volume. Measurements of hydrodynamic dissipation at the sagittal plane revealed no interaction between the inhalant and exhalant jet flow, indicating energy-efficient synchronized pumping mechanism. This efficient pumping mechanism is associated with the flow-turning angle between inhalant and exhalant jet flows, ∼90° (s.d. 12°).
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Affiliation(s)
- Fazil E Uslu
- Mechanical Engineering Department, Koc University, Istanbul 34450, Turkey
| | - Kerem Pekkan
- Mechanical Engineering Department, Koc University, Istanbul 34450, Turkey
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Riisgård HU, Funch P, Larsen PS. The mussel filter-pump - present understanding, with a re-examination of gill preparations. ACTA ZOOL-STOCKHOLM 2014. [DOI: 10.1111/azo.12110] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hans Ulrik Riisgård
- Marine Biological Research Centre; University of Southern Denmark; Hindsholmvej 11 DK-5300 Kerteminde Denmark
| | - Peter Funch
- Department of Bioscience; Genetics, Ecology and Evolution; Ny Munkegade 116, building 1540, room 215 8000 Aarhus C Denmark
| | - Poul S. Larsen
- DTU Mechanical Engineering; Fluid Mechanics; Technical University of Denmark; Building 403 DK-2800 Kongens Lyngby Denmark
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Knight K. Mussels waft water with precision. J Exp Biol 2014. [DOI: 10.1242/jeb.109710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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