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Rimbach R, Amireh A, Allen A, Hare B, Guarino E, Kaufman C, Salomons H, Pontzer H. Total energy expenditure of bottlenose dolphins (Tursiops truncatus) of different ages. J Exp Biol 2021; 224:271194. [PMID: 34350948 DOI: 10.1242/jeb.242218] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 06/30/2021] [Indexed: 11/20/2022]
Abstract
Marine mammals are thought to have an energetically expensive lifestyle because endothermy is costly in marine environments. However, measurements of total energy expenditure (TEE; kcal day-1) are available only for a limited number of marine mammals, because large body size and inaccessible habitats make TEE measurements expensive and difficult to obtain for many taxa. We measured TEE in 10 adult common bottlenose dolphins (Tursiops truncatus) living in natural seawater lagoons at two facilities (Dolphin Research Center and Dolphin Quest) using the doubly labeled water method. We assessed the relative effects of body mass, age and physical activity on TEE. We also examined whether TEE of bottlenose dolphins, and more generally of marine mammals, differs from that expected for their body mass compared with other eutherian mammals, using phylogenetic least squares (PGLS) regressions. There were no differences in body mass or TEE (unadjusted TEE and TEE adjusted for fat-free mass) between dolphins from the two facilities. Our results show that adjusted TEE decreased and fat mass increased with age. Different measures of activity were not related to age, body fat or adjusted TEE. Both PGLS and the non-phylogenetic linear regression indicate that marine mammals have an elevated TEE compared with that of terrestrial mammals. However, bottlenose dolphins expended 17.1% less energy than other marine mammals of similar body mass. The two oldest dolphins (>40 years) showed a lower TEE, similar to the decline in TEE seen in older humans. To our knowledge, this is the first study to show an age-related metabolic decline in a large non-human mammal.
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Affiliation(s)
- Rebecca Rimbach
- Evolutionary Anthropology, Duke University, Durham, NC 27708, USA.,School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, WITS 2050, South Africa
| | - Ahmad Amireh
- Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | - Austin Allen
- Duke University Marine Lab, Beaufort, NC 28516, USA
| | - Brian Hare
- Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | | | - Chana Kaufman
- Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | - Hannah Salomons
- Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | - Herman Pontzer
- Evolutionary Anthropology, Duke University, Durham, NC 27708, USA.,Duke Global Health Institute, Duke University, Durham, NC 27710, USA
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2
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RESPIRATORY CHANGES IN STRANDED BOTTLENOSE DOLPHINS ( TURSIOPS TRUNCATUS). J Zoo Wildl Med 2021; 52:49-56. [PMID: 33827160 DOI: 10.1638/2020-0033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/15/2020] [Indexed: 11/21/2022] Open
Abstract
Lung function (breath duration, respiratory flow [V̇], and tidal volume [VT]), and end-expiratory O2 were measured in 19 adult bottlenose dolphins (Tursiops spp.) while at rest in water or beached for up to 10 min. The results show that inspiratory VT, expiratory VT, or inspiratory V̇ did not differ on land or in water. The average expiratory V̇ for all dolphins on land decreased by 16%, and the expiratory and total breath durations increased by 5% and 4%, respectively, compared with in water. There were temporal changes observed during beaching, where expired and inspired VT and inspired V̇ decreased by 13%, 16%, and 9%, respectively, after 10 min on land. These data suggest that dolphins compensate for the effect of gravity by adjusting respiration to maintain alveolar ventilation and gas exchange, but during extended durations, the increased work of breathing may impede ventilation and gas exchange. Continuous monitoring of lung function and gas exchange may help prevent long-term damage during out-of-water medical procedures, optimize animal transport conditions, and improve survival during stranding events.
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3
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Fahlman A, Cozzi B, Manley M, Jabas S, Malik M, Blawas A, Janik VM. Conditioned Variation in Heart Rate During Static Breath-Holds in the Bottlenose Dolphin ( Tursiops truncatus). Front Physiol 2020; 11:604018. [PMID: 33329056 PMCID: PMC7732665 DOI: 10.3389/fphys.2020.604018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 10/28/2020] [Indexed: 02/03/2023] Open
Abstract
Previous reports suggested the existence of direct somatic motor control over heart rate (f H) responses during diving in some marine mammals, as the result of a cognitive and/or learning process rather than being a reflexive response. This would be beneficial for O2 storage management, but would also allow ventilation-perfusion matching for selective gas exchange, where O2 and CO2 can be exchanged with minimal exchange of N2. Such a mechanism explains how air breathing marine vertebrates avoid diving related gas bubble formation during repeated dives, and how stress could interrupt this mechanism and cause excessive N2 exchange. To investigate the conditioned response, we measured the f H-response before and during static breath-holds in three bottlenose dolphins (Tursiops truncatus) when shown a visual symbol to perform either a long (LONG) or short (SHORT) breath-hold, or during a spontaneous breath-hold without a symbol (NS). The average f H (if Hstart), and the rate of change in f H (dif H/dt) during the first 20 s of the breath-hold differed between breath-hold types. In addition, the minimum instantaneous f H (if Hmin), and the average instantaneous f H during the last 10 s (if Hend) also differed between breath-hold types. The dif H/dt was greater, and the if Hstart, if Hmin, and if Hend were lower during a LONG as compared with either a SHORT, or an NS breath-hold (P < 0.05). Even though the NS breath-hold dives were longer in duration as compared with SHORT breath-hold dives, the dif H/dt was greater and the if Hstart, if Hmin, and if Hend were lower during the latter (P < 0.05). In addition, when the dolphin determined the breath-hold duration (NS), the f H was more variable within and between individuals and trials, suggesting a conditioned capacity to adjust the f H-response. These results suggest that dolphins have the capacity to selectively alter the f H-response during diving and provide evidence for significant cardiovascular plasticity in dolphins.
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Affiliation(s)
- Andreas Fahlman
- Global Diving Research Inc., Ottawa, ON, Canada
- Research Department, Fundación Oceanogràfic de la Comunidad Valenciana, Valencia, Spain
| | - Bruno Cozzi
- Department of Comparative Biomedicine and Food Science, University of Padua, Legnaro, Italy
| | - Mercy Manley
- Siegfried & Roy’s Secret Garden and Dolphin Habitat, The Mirage, Las Vegas, NV, United States
| | - Sandra Jabas
- Siegfried & Roy’s Secret Garden and Dolphin Habitat, The Mirage, Las Vegas, NV, United States
| | - Marek Malik
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
- Department of Internal Cardiology Medicine, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Ashley Blawas
- Nicholas School of the Environment, Duke University Marine Laboratory, Beaufort, NC, United States
| | - Vincent M. Janik
- Sea Mammal Research Unit, Scottish Oceans Institute, School of Biology, University of St Andrews, St Andrews, United Kingdom
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4
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Hart LB, Dziobak MK, Pisarski EC, Wirth EF, Wells RS. Sentinels of synthetics - a comparison of phthalate exposure between common bottlenose dolphins (Tursiops truncatus) and human reference populations. PLoS One 2020; 15:e0240506. [PMID: 33057361 PMCID: PMC7561143 DOI: 10.1371/journal.pone.0240506] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 09/29/2020] [Indexed: 11/26/2022] Open
Abstract
Phthalates are chemical esters used as additives in common consumer goods, such as plastics, household cleaners, and personal care products. Phthalates are not chemically bound to the items to which they are added and can easily leach into the surrounding environment. Anthropogenic drivers, such as coastal plastic pollution and wastewater runoff, increase the exposure potential for coastal marine fauna. Phthalate exposure in free-ranging bottlenose dolphins has been the focus of recent study, with indications of heightened exposure to certain phthalate compounds. The objective of this study was to compare urinary phthalate metabolite concentrations among bottlenose dolphins (Tursiops truncatus) sampled in Sarasota Bay, FL, to levels reported in human samples collected as part of the Centers for Disease Control and Prevention's (CDC) National Health and Nutrition Examination Survey (NHANES). Monoethyl phthalate (MEP) and mono-(2-ethylhexyl) phthalate (MEHP) were the most prevalent metabolites detected in dolphin urine (n = 51; MEP = 29.41%; MEHP = 54.90%). The geometric mean (GM) concentration of MEP was significantly lower for dolphins (GM = 4.51 ng/mL; 95% CI: 2.77-7.34 ng/mL) compared to humans (p<0.05), while dolphin concentrations of MEHP (GM = 4.57 ng/mL; 95% CI: 2.37-8.80 ng/mL) were significantly higher than levels reported in NHANES (p<0.05). Health impacts to bottlenose dolphins resulting from elevated exposure to the MEHP parent compound (diethyl-2-ethylhexyl phthalate, DEHP) are currently unknown. However, given the evidence of endocrine disruption, reproductive impairment, and abnormal development in humans, pursuing investigations of potential health effects in exposed bottlenose dolphins would be warranted.
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Affiliation(s)
- Leslie B. Hart
- Department of Health and Human Performance, College of Charleston, Charleston, SC, United States of America
| | - Miranda K. Dziobak
- Environmental and Sustainability Studies Graduate Program, College of Charleston, Charleston, SC, United States of America
| | - Emily C. Pisarski
- CSS Inc., NOAA NCCOS Charleston Lab, Charleston, SC, United States of America
| | - Edward F. Wirth
- National Oceanic and Atmospheric Administration, NOAA NCCOS Charleston Lab, Charleston, SC, United States of America
| | - Randall S. Wells
- Chicago Zoological Society’s Sarasota Dolphin Research Program, c/o Mote Marine Laboratory, Sarasota, FL, United States of America
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5
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Quick NJ, Cioffi WR, Shearer JM, Fahlman A, Read AJ. Extreme diving in mammals: first estimates of behavioural aerobic dive limits in Cuvier's beaked whales. J Exp Biol 2020; 223:223/18/jeb222109. [DOI: 10.1242/jeb.222109] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 07/13/2020] [Indexed: 01/08/2023]
Abstract
ABSTRACT
We analysed 3680 dives from 23 satellite-linked tags deployed on Cuvier's beaked whales to assess the relationship between long duration dives and inter-deep dive intervals and to estimate aerobic dive limit (ADL). The median duration of presumed foraging dives was 59 min and 5% of dives exceeded 77.7 min. We found no relationship between the longest 5% of dive durations and the following inter-deep dive interval nor any relationship with the ventilation period immediately prior to or following a long dive. We suggest that Cuvier's beaked whales have low metabolic rates, high oxygen storage capacities and a high acid-buffering capacity to deal with the by-products of both aerobic and anaerobic metabolism, which enables them to extend dive durations and exploit their bathypelagic foraging habitats.
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Affiliation(s)
- Nicola J. Quick
- Duke University Marine Laboratory, Marine Science and Conservation, Nicholas School of the Environment, Beaufort, NC 28516, USA
| | - William R. Cioffi
- Duke University Marine Laboratory, University Program in Ecology, Nicholas School of the Environment, Beaufort, NC 28516, USA
| | - Jeanne M. Shearer
- Duke University Marine Laboratory, University Program in Ecology, Nicholas School of the Environment, Beaufort, NC 28516, USA
| | - Andreas Fahlman
- Fundación Oceanogràfic de la Comunitat Valencia, Valencia, 46005, Spain
| | - Andrew J. Read
- Duke University Marine Laboratory, Marine Science and Conservation, Nicholas School of the Environment, Beaufort, NC 28516, USA
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6
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Fahlman A, Sato K, Miller P. Improving estimates of diving lung volume in air-breathing marine vertebrates. ACTA ACUST UNITED AC 2020; 223:223/12/jeb216846. [PMID: 32587107 DOI: 10.1242/jeb.216846] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The air volume in the respiratory system of marine tetrapods provides a store of O2 to fuel aerobic metabolism during dives; however, it can also be a liability, as the associated N2 can increase the risk of decompression sickness. In order to more fully understand the physiological limitations of different air-breathing marine vertebrates, it is therefore important to be able to accurately estimate the air volume in the respiratory system during diving. One method that has been used to do so is to calculate the air volume from glide phases - periods of movement during which no thrust is produced by the animal - which many species conduct during ascent periods, when gases are expanding owing to decreasing hydrostatic pressure. This method assumes that there is conservation of mass in the respiratory system, with volume changes only driven by pressure. In this Commentary, we use previously published data to argue that both the respiratory quotient and differences in tissue and blood gas solubility potentially alter the mass balance in the respiratory system throughout a dive. Therefore, near the end of a dive, the measured volume of gas at a given pressure may be 12-50% less than from the start of the dive; the actual difference will depend on the length of the dive, the cardiac output, the pulmonary shunt and the metabolic rate. Novel methods and improved understanding of diving physiology will be required to verify the size of the effects described here and to more accurately estimate the volume of gas inhaled at the start of a dive.
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Affiliation(s)
- Andreas Fahlman
- Global Diving Research Inc., Ottawa, ON, Canada, K2J 5E8 .,Fundación Oceanogràfic de la Comunitat Valenciana, Gran Vía Marqués del Turia 19, 46005 Valencia, Spain
| | - Katsufumi Sato
- Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564, Japan
| | - Patrick Miller
- SMRU (Sea Mammal Research Unit), University of St Andrews, St Andrews, Fife KY16 8LB, UK
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Fahlman A, Borque-Espinosa A, Facchin F, Fernandez DF, Caballero PM, Haulena M, Rocho-Levine J. Comparative Respiratory Physiology in Cetaceans. Front Physiol 2020; 11:142. [PMID: 32194433 PMCID: PMC7063064 DOI: 10.3389/fphys.2020.00142] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 02/11/2020] [Indexed: 11/26/2022] Open
Abstract
In the current study, we used breath-by-breath respirometry to evaluate respiratory physiology under voluntary control in a male beluga calf [Delphinapterus leucas, body mass range (M b): 151-175 kg], an adult female (estimated M b = 500-550 kg) and a juvenile male (M b = 279 kg) false killer whale (Pseudorca crassidens) housed in managed care. Our results suggest that the measured breathing frequency (f R) is lower, while tidal volume (V T) is significantly greater as compared with allometric predictions from terrestrial mammals. Including previously published data from adult bottlenose dolphin (Tursiops truncatus) beluga, harbor porpoise (Phocoena phocoena), killer whale (Orcinus orca), pilot whale (Globicephala scammoni), and gray whale (Eschrichtius robustus) show that the allometric mass-exponents for V T and f R are similar to that for terrestrial mammals (V T: 1.00, f R: -0.20). In addition, our results suggest an allometric relationship for respiratory flow ( V . ), with a mass-exponent between 0.63 and 0.70, and where the expiratory V . was an average 30% higher as compared with inspiratory V . . These data provide enhanced understanding of the respiratory physiology of cetaceans and are useful to provide proxies of lung function to better understand lung health or physiological limitations.
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Affiliation(s)
- Andreas Fahlman
- Research Department, Fundación Oceanogràfic de la Comunitat Valenciana, Valencia, Spain
- Global Diving Research Inc., Ottawa, ON, Canada
| | - Alicia Borque-Espinosa
- Research Department, Fundación Oceanogràfic de la Comunitat Valenciana, Valencia, Spain
- University of Valencia, Valencia, Spain
| | - Federico Facchin
- Research Department, Fundación Oceanogràfic de la Comunitat Valenciana, Valencia, Spain
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8
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Borque-Espinosa A, Burgos F, Dennison S, Laughlin R, Manley M, Capaccioni Azzati R, Fahlman A. Pulmonary function testing as a diagnostic tool to assess respiratory health in bottlenose dolphins Tursiops truncatus. DISEASES OF AQUATIC ORGANISMS 2020; 138:17-27. [PMID: 32052791 DOI: 10.3354/dao03447] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Pulmonary function testing was performed in 3 bottlenose dolphins Tursiops truncatus (1 female and 2 males) under managed care during a 2 yr period to assess whether these data provide diagnostic information about respiratory health. Pulmonary radiographs and standard clinical testing were used to evaluate the pulmonary health of each dolphin. The female dolphin (F1) had evidence of chronic pulmonary fibrosis, and 1 male (M2) developed pneumonia during the study. Pulmonary function data were collected from maximal respiratory efforts in water and from spontaneous breaths while beached. From these data, the flow-volume relationship, the flow measured between 25 and 75% of the expired vital capacity (mid forced expiratory flow, FEF25%-75%), and the percent of the vital capacity (VC) at the peak expiratory flow (%VCPEF), were evaluated and compared with the diagnostic assessment. For maximal respiratory manoeuvres in water, there were no differences in FEF25%-75% or %VCPEF, and the flow-volume relationship showed a consistent pattern for F1. Additionally, FEF25%-75% and %VCPEF decreased by 27 and 52%, respectively, and the flow-volume relationship showed clear flow limitations with emerging disease in M2. While spontaneously breathing on land, M2 also showed a 49% decrease in %VCPEF and changes in the flow-volume relationship, indicating flow limitations following the development of pneumonia. Based on these preliminary results, we suggest that pulmonary function testing should be given more attention as a non-invasive and possibly adjunctive diagnostic tool to evaluate lung health of dolphins under managed care and in the wild.
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Affiliation(s)
- A Borque-Espinosa
- Research Department, Fundación Oceanogràfic de la Comunitat Valenciana, Valencia 46005, Spain
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9
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Fahlman A, Brodsky M, Miedler S, Dennison S, Ivančić M, Levine G, Rocho-Levine J, Manley M, Rocabert J, Borque-Espinosa A. Ventilation and gas exchange before and after voluntary static surface breath-holds in clinically healthy bottlenose dolphins, Tursiops truncatus. ACTA ACUST UNITED AC 2019; 222:jeb.192211. [PMID: 30760549 DOI: 10.1242/jeb.192211] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 02/05/2019] [Indexed: 01/14/2023]
Abstract
We measured respiratory flow (V̇), breathing frequency (f R), tidal volume (V T), breath duration and end-expired O2 content in bottlenose dolphins (Tursiops truncatus) before and after static surface breath-holds ranging from 34 to 292 s. There was considerable variation in the end-expired O2, V T and f R following a breath-hold. The analysis suggests that the dolphins attempt to minimize recovery following a dive by altering V T and f R to rapidly replenish the O2 stores. For the first breath following a surface breath-hold, the end-expired O2 decreased with dive duration, while V T and f R increased. Throughout the recovery period, end-expired O2 increased while the respiratory effort (V T, f R) decreased. We propose that the dolphins alter respiratory effort following a breath-hold according to the reduction in end-expired O2 levels, allowing almost complete recovery after 1.2 min.
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Affiliation(s)
- Andreas Fahlman
- Departamento de investigación, Fundación Oceanogràfic de la Comunitat Valenciana, Gran Vía Marqués del Turia 19, 46005 Valencia, Spain .,Departamento de Zoología, Grupo de Investigación Biomédica en Imagen GIBI230, Instituto de Investigación Sanitaria La Fe, Av. Fernando Abril Martorell 106, 46026 Valencia, Spain
| | - Micah Brodsky
- Micah Brodsky, V.M.D. Consulting, 1287 NE 96th Street, Miami Shores, FL 33138, USA
| | - Stefan Miedler
- Departamento de investigación, Fundación Oceanogràfic de la Comunitat Valenciana, Gran Vía Marqués del Turia 19, 46005 Valencia, Spain
| | - Sophie Dennison
- TeleVet Imaging Solutions, PLLC, PO BOX 3344, Oakton, VA 22124, USA
| | - Marina Ivančić
- Chicago Zoological Society, 3300 Golf Road, Brookfield, IL 60513, USA
| | - Gregg Levine
- Dolphin Quest, Oahu, 5000 Kahala Ave, Honolulu, HI 96816, USA
| | | | - Mercy Manley
- Siegfried & Roy's Secret Garden and Dolphin Habitat, The Mirage, Las Vegas, NV 89109, USA
| | - Joan Rocabert
- Mellow Design, C/ Bany dels pavesos 3, 46001 Valencia, Spain
| | - Alicia Borque-Espinosa
- Departamento de investigación, Fundación Oceanogràfic de la Comunitat Valenciana, Gran Vía Marqués del Turia 19, 46005 Valencia, Spain.,Departamento de Zoología, Grupo de Investigación Biomédica en Imagen GIBI230, Instituto de Investigación Sanitaria La Fe, Av. Fernando Abril Martorell 106, 46026 Valencia, Spain.,Universidad de Valencia, Av. de Blasco Ibáñez, 13, 46010 Valencia, Spain
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10
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Cauture F, Sterba-Boatwright B, Rocho-Levine J, Harms C, Miedler S, Fahlman A. Using Respiratory Sinus Arrhythmia to Estimate Inspired Tidal Volume in the Bottlenose Dolphin ( Tursiops truncatus). Front Physiol 2019; 10:128. [PMID: 30837895 PMCID: PMC6390636 DOI: 10.3389/fphys.2019.00128] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 02/01/2019] [Indexed: 11/21/2022] Open
Abstract
Man-made environmental change may have significant impact on apex predators, like marine mammals. Thus, it is important to assess the physiological boundaries for survival in these species, and assess how climate change may affect foraging efficiency and the limits for survival. In the current study, we investigated whether the respiratory sinus arrhythmia (RSA) could estimate tidal volume (V T) in resting bottlenose dolphins (Tursiops truncatus). For this purpose, we measured respiratory flow and electrocardiogram (ECG) in five adult bottlenose dolphins at rest while breathing voluntarily. Initially, an exponential decay function, using three parameters (baseline heart rate, the change in heart rate following a breath, and an exponential decay constant) was used to describe the temporal change in instantaneous heart rate following a breath. The three descriptors, in addition to body mass, were used to develop a Generalized Additive Model (GAM) to predict the inspired tidal volume (V Tinsp). The GAM allowed us to predict V Tinsp with an average ( ± SD) overestimate of 3 ± 2%. A jackknife sensitivity analysis, where 4 of the five dolphins were used to fit the GAM and the 5th dolphin used to make predictions resulted in an average overestimate of 2 ± 10%. Future studies should be used to assess whether similar relationships exist in active animals, allowing V T to be studied in free-ranging animals provided that heart rate can be measured.
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Affiliation(s)
- Fabien Cauture
- Departamento de Investigación, Fundación Oceanogràfic de la Comunidad Valenciana, Valencia, Spain
| | - Blair Sterba-Boatwright
- Department of Mathematics and Statistics, Texas A&M University–Corpus Christi, Corpus Christi, TX, United States
| | | | - Craig Harms
- Center for Marine Sciences and Technology, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Morehead City, NC, United States
| | | | - Andreas Fahlman
- Departamento de Investigación, Fundación Oceanogràfic de la Comunidad Valenciana, Valencia, Spain
- Research Group on Biomedical Imaging (GIBI2), Instituto de Investigación Sanitaria La Fe, Valencia, Spain
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11
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Nabi G, Hao Y, McLaughlin RW, Wang D. The Possible Effects of High Vessel Traffic on the Physiological Parameters of the Critically Endangered Yangtze Finless Porpoise ( Neophocaena asiaeorientalis ssp. asiaeorientalis). Front Physiol 2018; 9:1665. [PMID: 30546317 PMCID: PMC6280126 DOI: 10.3389/fphys.2018.01665] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 11/05/2018] [Indexed: 11/13/2022] Open
Abstract
Background: Poyang is the largest freshwater lake in China, where the acoustic environment and space for the critically endangered Yangtze finless porpoises (YFPs) has been altered by heavy vessel traffic and dredging activities. The density of vessel and the rate of dredging increases annually, especially in the area with the highest density of YFPs. The heavy vessel traffic can cause an increase in the physical activities and direct physical injuries to the YFPs. Furthermore, noise is a potent stressor to all cetaceans irrespective of age and can compromise all their physiological functions. The objective of this study was to examine the possible effects of heavy vessel traffic and dredging on the biochemistry, hematology, adrenal, thyroid, and reproductive hormones of two different YFP populations. One population was living in Poyang Lake and the second living in the Tian-E-Zhou Oxbow which is a semi-natural resserve. Results: The results showed statistically significantly higher levels of serum cortisol, fT3, fT4, and lowered testosterone in both adult and juvenile YFPs living in Poyang Lake vs. adult YFPs living in the Tian-E-Zhou Oxbow. The serum biochemical parameters (Aspartate Amino Transferase, Alkaline Phosphatase, High Density Lipoprotein cholesterol ratio, Globulin, Uric acid, Glucose, K+, and Amylase) and the hematology parameters (Red Blood Cells, Hematocrit, Mean Corpuscular Volume, White Blood Cells, and Eosinophils) were statistically significantly higher in the adult Poyang Lake YFPs vs. adult Tian-E-Zhou Oxbow YFPs. On the other hand, adult males of the Tian-E-Zhou Oxbow also showed significantly higher levels of the serum biochemical parameters (Total Cholesterol, Light Density Lipoprotein cholesterol, Direct Bilirubin, Albumin, Lactate Dehydrogenase, CO2, and Na+) and the blood parameters (Mean Corpuscular Hemoglobin and Mean Corpuscular Hemoglobin Concentration). In Poyang Lake YFPs, various parameters showed significantly positive (fT4, amylase, neutrophil, Ca+2) or negative (total protein, lymphocyte) correlations with cortisol levels. Conclusions: The hyperactivity of adrenal glands in response to heavy vessel traffic and dredging resulted in significantly elevated cortisol levels in Poyang Lake YFPs. The higher cortisol level could possibly have affected various hormonal, hematological, and biochemical parameters, and ultimately the YFPs physiology.
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Affiliation(s)
- Ghulam Nabi
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yujiang Hao
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | | | - Ding Wang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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12
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Fahlman A, Jensen FH, Tyack PL, Wells RS. Modeling Tissue and Blood Gas Kinetics in Coastal and Offshore Common Bottlenose Dolphins, Tursiops truncatus. Front Physiol 2018; 9:838. [PMID: 30072907 PMCID: PMC6060447 DOI: 10.3389/fphys.2018.00838] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 06/14/2018] [Indexed: 01/07/2023] Open
Abstract
Bottlenose dolphins (Tursiops truncatus) are highly versatile breath-holding predators that have adapted to a wide range of foraging niches from rivers and coastal ecosystems to deep-water oceanic habitats. Considerable research has been done to understand how bottlenose dolphins manage O2 during diving, but little information exists on other gases or how pressure affects gas exchange. Here we used a dynamic multi-compartment gas exchange model to estimate blood and tissue O2, CO2, and N2 from high-resolution dive records of two different common bottlenose dolphin ecotypes inhabiting shallow (Sarasota Bay) and deep (Bermuda) habitats. The objective was to compare potential physiological strategies used by the two populations to manage shallow and deep diving life styles. We informed the model using species-specific parameters for blood hematocrit, resting metabolic rate, and lung compliance. The model suggested that the known O2 stores were sufficient for Sarasota Bay dolphins to remain within the calculated aerobic dive limit (cADL), but insufficient for Bermuda dolphins that regularly exceeded their cADL. By adjusting the model to reflect the body composition of deep diving Bermuda dolphins, with elevated muscle mass, muscle myoglobin concentration and blood volume, the cADL increased beyond the longest dive duration, thus reflecting the necessary physiological and morphological changes to maintain their deep-diving life-style. The results indicate that cardiac output had to remain elevated during surface intervals for both ecotypes, and suggests that cardiac output has to remain elevated during shallow dives in-between deep dives to allow sufficient restoration of O2 stores for Bermuda dolphins. Our integrated modeling approach contradicts predictions from simple models, emphasizing the complex nature of physiological interactions between circulation, lung compression, and gas exchange.
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Affiliation(s)
- Andreas Fahlman
- Global Diving Research, Ottawa, ON, Canada
- Fundación Oceanografic de la Comunidad Valenciana, Valencia, Spain
| | - Frants H. Jensen
- Aarhus Institute of Advanced Studies, Aarhus University, Aarhus, Denmark
| | - Peter L. Tyack
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, United Kingdom
| | - Randall S. Wells
- Chicago Zoological Society's Sarasota Dolphin Research Program, Mote Marine Laboratory, Sarasota, FL, United States
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