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Royer M, Meyer C, Royer J, Maloney K, Cardona E, Blandino C, Fernandes da Silva G, Whittingham K, Holland KN. "Breath holding" as a thermoregulation strategy in the deep-diving scalloped hammerhead shark. Science 2023; 380:651-655. [PMID: 37167384 DOI: 10.1126/science.add4445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Fish moving between different thermal environments experience heat exchange via conduction through the body wall and convection from blood flow across the gills. We report a strategy of preventing convective heat loss at the gills during excursions into deep, cold water by the tropical scalloped hammerhead shark (Sphryna lewini). Adult scalloped hammerhead sharks dive rapidly and repeatedly from warm (~26°C) surface waters to depths exceeding 800 meters with temperatures as low as 5°C. Biologgers attached to adult sharks show that warm muscle temperatures were maintained throughout the deepest portion of each dive. Substantive cooling only occurred during the latter stages of the ascent phase and, once initiated, was rapid. Heat transfer coefficient modeling indicated that convective heat transfer was suspended, probably by suppressing gill function during deep dives. This previously unobserved strategy has broad similarities to marine mammal "breath hold" diving.
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Affiliation(s)
- Mark Royer
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI 96744, USA
| | - Carl Meyer
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI 96744, USA
| | - John Royer
- School of Physics and Astronomy, The University of Edinburgh, Edinburgh EH9 3FD, UK
| | - Kelsey Maloney
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI 96744, USA
| | - Edward Cardona
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI 96744, USA
| | - Chloé Blandino
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI 96744, USA
| | - Guilherme Fernandes da Silva
- Department of Marine Sciences, Federal University of São Paulo, 11070-102 Santos, Brazil
- Ocean and Resources Engineering, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA
| | | | - Kim N Holland
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI 96744, USA
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2
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Birkedal R, Laasmaa M, Branovets J, Vendelin M. Ontogeny of cardiomyocytes: ultrastructure optimization to meet the demand for tight communication in excitation-contraction coupling and energy transfer. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210321. [PMID: 36189816 PMCID: PMC9527910 DOI: 10.1098/rstb.2021.0321] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The ontogeny of the heart describes its development from the fetal to the adult stage. In newborn mammals, blood pressure and thus cardiac performance are relatively low. The cardiomyocytes are thin, and with a central core of mitochondria surrounded by a ring of myofilaments, while the sarcoplasmic reticulum (SR) is sparse. During development, as blood pressure and performance increase, the cardiomyocytes become more packed with structures involved in excitation–contraction (e-c) coupling (SR and myofilaments) and the generation of ATP (mitochondria) to fuel the contraction. In parallel, the e-c coupling relies increasingly on calcium fluxes through the SR, while metabolism relies increasingly on fatty acid oxidation. The development of transverse tubules and SR brings channels and transporters interacting via calcium closer to each other and is crucial for e-c coupling. However, for energy transfer, it may seem counterintuitive that the increased structural density restricts the overall ATP/ADP diffusion. In this review, we discuss how this is because of the organization of all these structures forming modules. Although the overall diffusion across modules is more restricted, the energy transfer within modules is fast. A few studies suggest that in failing hearts this modular design is disrupted, and this may compromise intracellular energy transfer. This article is part of the theme issue ‘The cardiomyocyte: new revelations on the interplay between architecture and function in growth, health, and disease’.
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Affiliation(s)
- Rikke Birkedal
- Laboratory of Systems Biology, Department of Cybernetics, Tallinn University of Technology, Akadeemia 15, room SCI-218, 12618 Tallinn, Estonia
| | - Martin Laasmaa
- Laboratory of Systems Biology, Department of Cybernetics, Tallinn University of Technology, Akadeemia 15, room SCI-218, 12618 Tallinn, Estonia
| | - Jelena Branovets
- Laboratory of Systems Biology, Department of Cybernetics, Tallinn University of Technology, Akadeemia 15, room SCI-218, 12618 Tallinn, Estonia
| | - Marko Vendelin
- Laboratory of Systems Biology, Department of Cybernetics, Tallinn University of Technology, Akadeemia 15, room SCI-218, 12618 Tallinn, Estonia
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3
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Reid CH, Patrick PH, Rytwinski T, Taylor JJ, Willmore WG, Reesor B, Cooke SJ. An updated review of cold shock and cold stress in fish. JOURNAL OF FISH BIOLOGY 2022; 100:1102-1137. [PMID: 35285021 DOI: 10.1111/jfb.15037] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 01/23/2022] [Accepted: 03/07/2022] [Indexed: 06/14/2023]
Abstract
Temperature is critical in regulating virtually all biological functions in fish. Low temperature stress (cold shock/stress) is an often-overlooked challenge that many fish face as a result of both natural events and anthropogenic activities. In this study, we present an updated review of the cold shock literature based on a comprehensive literature search, following an initial review on the subject by M.R. Donaldson and colleagues, published in a 2008 volume of this journal. We focus on how knowledge on cold shock and fish has evolved over the past decade, describing advances in the understanding of the generalized stress response in fish under cold stress, what metrics may be used to quantify cold stress and what knowledge gaps remain to be addressed in future research. We also describe the relevance of cold shock as it pertains to environmental managers, policymakers and industry professionals, including practical applications of cold shock. Although substantial progress has been made in addressing some of the knowledge gaps identified a decade ago, other topics (e.g., population-level effects and interactions between primary, secondary and tertiary stress responses) have received little or no attention despite their significance to fish biology and thermal stress. Approaches using combinations of primary, secondary and tertiary stress responses are crucial as a research priority to better understand the mechanisms underlying cold shock responses, from short-term physiological changes to individual- and population-level effects, thereby providing researchers with better means of quantifying cold shock in laboratory and field settings.
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Affiliation(s)
- Connor H Reid
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | | | - Trina Rytwinski
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, Ontario, Canada
- Canadian Centre for Evidence-Based Conservation, Department of Biology and Institute of Environmental and Interdisciplinary Science, Carleton University, Ottawa, Ontario, Canada
| | - Jessica J Taylor
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, Ontario, Canada
- Canadian Centre for Evidence-Based Conservation, Department of Biology and Institute of Environmental and Interdisciplinary Science, Carleton University, Ottawa, Ontario, Canada
| | | | | | - Steven J Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, Ontario, Canada
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4
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Crossley DA, Stieglitz JD, Benetti DD, Grosell M. The effects of acute temperature change and digestive status on in situ cardiac function in mahi-mahi (Coryphaena hippurus). Comp Biochem Physiol A Mol Integr Physiol 2021; 255:110915. [PMID: 33621645 DOI: 10.1016/j.cbpa.2021.110915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/26/2021] [Accepted: 01/26/2021] [Indexed: 12/25/2022]
Abstract
In this study, we investigated the effect of acute increases in temperature on cardiovascular function of mahi-mahi (Coryphaena hippurus). We also describe, for the first time, an artery that supplies the gastrointestinal tract that originates from the fourth branchial artery. We used vascular casting to verify the anatomical location of this unique celiaco-mesenteric artery. We predicted that blood flow in this vessel would be correlated with the digestive state of the animal. Increasing water temperature from 25.0 to 30.5 °C resulted in a linear increase in heart rate (fH) from 165 ± 4 beats∙min-1to 232 ± 7 beats∙min-1. Over this temperature range, fH strongly correlated with water temperature (R2 = 0.79). At 31 °C fH no longer correlated with water temperature, and at 34 °C fH had dropped to 114 ± 19 beats∙min-1. Furthermore, we found that mahi are capable of maintaining constant cardiac output over a temperature range from 25 to 31 °C. Cardiac function appeared to be compromised at temperatures >31 °C. In fed anesthetized fish, blood flow was pulsatile in the celiaco-mesenteric artery and was not in fasted fish. In fed fish, blood flow in the left celiaco-mesenteric artery was 1.99 ± 0.78 ml·min-1·kg-1 compared to the total cardiac output of 168.6 ± 12.7 ml·min-1·kg-1. The data suggest that mahi can differentially regulate gastric blood flow based on feeding state, which may explain the high digestive efficiency and very high growth rates of these pelagic predators.
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Affiliation(s)
- Dane A Crossley
- Department of Biological Sciences, University of North Texas, 1155 Union Circle, Denton, TX 76203, United States.
| | - John D Stieglitz
- Department of Marine Ecosystems and Society, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149-1098, United States
| | - Daniel D Benetti
- Department of Marine Ecosystems and Society, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149-1098, United States
| | - Martin Grosell
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149-1098, United States
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5
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Stoehr AA, Donley JM, Aalbers SA, Syme DA, Sepulveda C, Bernal D. Thermal effects on red muscle contractile performance in deep-diving, large-bodied fishes. FISH PHYSIOLOGY AND BIOCHEMISTRY 2020; 46:1833-1845. [PMID: 32588156 DOI: 10.1007/s10695-020-00831-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 05/28/2020] [Indexed: 06/11/2023]
Abstract
Bigeye thresher sharks (Alopias superciliosus) and swordfish (Xiphias gladius) are large, pelagic fishes, which make long-duration, diurnal foraging dives from warm, surface waters (18-24 °C) to cold waters beneath the thermocline (5-10 °C). In bigeye thresher sharks, the subcutaneous position of the red, aerobic swimming muscles (RM) suggests that RM temperature mirrors ambient during dives (i.e., ectothermy). In swordfish, the RM is closer to the vertebrae and its associated with vascular counter-current heat exchangers that maintain RM temperature above ambient (i.e., RM endothermy). Here, we sought to determine how exposure to a wide range of ambient temperatures (8, 16, 24 °C) impacted peak power output and optimum cycle (i.e., tailbeat) frequency (0.25, 0.5, 1 Hz) in RM isolated from both species. Bigeye thresher shark RM did not produce substantial power at high cycle frequencies, even at high temperatures; but it did produce relatively high power at slow cycle frequencies regardless of temperature. Swordfish RM produced more power when operating at a combination of fast cycle frequencies and higher temperatures. This suggests that swordfish RM benefits considerably more from warming than bigeye thresher shark RM, while the RM of both species was able to produce power at cold temperatures and slow cycle frequencies. Despite different thermal strategies (i.e., ectothermy vs. RM endothermy), the ability of the RM to power sustained swimming during foraging-related search behaviors may contribute to the unique ability of these fishes to successfully exploit food resources in deep, cold water.
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Affiliation(s)
| | | | - Scott A Aalbers
- Pfleger Institute of Environmental Research, Oceanside, CA, USA
| | | | | | - Diego Bernal
- University of Massachusetts Dartmouth, Dartmouth, MA, USA.
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6
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Vornanen M. Effects of acute warming on cardiac and myotomal sarco(endo)plasmic reticulum ATPase (SERCA) of thermally acclimated brown trout (Salmo trutta). J Comp Physiol B 2020; 191:43-53. [PMID: 32980918 PMCID: PMC7819936 DOI: 10.1007/s00360-020-01313-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 08/21/2020] [Accepted: 09/09/2020] [Indexed: 11/24/2022]
Abstract
At high temperatures, ventricular beating rate collapses and depresses cardiac output in fish. The role of sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) in thermal tolerance of ventricular function was examined in brown trout (Salmo trutta) by measuring heart SERCA and comparing it to that of the dorsolateral myotomal muscle. Activity of SERCA was measured from crude homogenates of cold-acclimated (+ 3 °C, c.a.) and warm-acclimated (+ 13 °C, w.a.) brown trout as cyclopiazonic acid (20 µM) sensitive Ca2+-ATPase between + 3 and + 33 °C. Activity of the heart SERCA was significantly higher in c.a. than w.a. trout and increased strongly between + 3 and + 23 °C with linear Arrhenius plots but started to plateau between + 23 and + 33 °C in both acclimation groups. The rate of thermal inactivation of the heart SERCA at + 35 °C was similar in c.a. and w.a. fish. Activity of the muscle SERCA was less temperature dependent and more heat resistant than that of the heart SERCA and showed linear Arrhenius plots between + 3 and + 33 °C in both c.a. and w.a. fish. SERCA activity of the c.a. muscle was slightly higher than that of w.a. muscle. The rate of thermal inactivation at + 40 °C was similar for both c.a. and w.a. muscle SERCA at + 40 °C. Although the heart SERCA is more sensitive to high temperatures than the muscle SERCA, it is unlikely to be a limiting factor for heart rate, because its heat tolerance, unlike that of the ventricular beating rate, was not changed by temperature acclimation.
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Affiliation(s)
- Matti Vornanen
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, 80101, Joensuu, Finland.
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7
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Ciezarek A, Gardner L, Savolainen V, Block B. Skeletal muscle and cardiac transcriptomics of a regionally endothermic fish, the Pacific bluefin tuna, Thunnus orientalis. BMC Genomics 2020; 21:642. [PMID: 32942994 PMCID: PMC7499911 DOI: 10.1186/s12864-020-07058-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 09/08/2020] [Indexed: 11/29/2022] Open
Abstract
Background The Pacific bluefin tuna (Thunnus orientalis) is a regionally endothermic fish that maintains temperatures in their swimming musculature, eyes, brain and viscera above that of the ambient water. Within their skeletal muscle, a thermal gradient exists, with deep muscles, close to the backbone, operating at elevated temperatures compared to superficial muscles near the skin. Their heart, by contrast, operates at ambient temperature, which in bluefin tunas can range widely. Cardiac function in tunas reduces in cold waters, yet the heart must continue to supply blood for metabolically demanding endothermic tissues. Physiological studies indicate Pacific bluefin tuna have an elevated cardiac capacity and increased cold-tolerance compared to warm-water tuna species, primarily enabled by increased capacity for sarcoplasmic reticulum calcium cycling within the cardiac muscles. Results Here, we compare tissue-specific gene-expression profiles of different cardiac and skeletal muscle tissues in Pacific bluefin tuna. There was little difference in the overall expression of calcium-cycling and cardiac contraction pathways between atrium and ventricle. However, expression of a key sarcoplasmic reticulum calcium-cycling gene, SERCA2b, which plays a key role maintaining intracellular calcium stores, was higher in atrium than ventricle. Expression of genes involved in aerobic metabolism and cardiac contraction were higher in the ventricle than atrium. The two morphologically distinct tissues that derive the ventricle, spongy and compact myocardium, had near-identical levels of gene expression. More genes had higher expression in the cool, superficial muscle than in the warm, deep muscle in both the aerobic red muscle (slow-twitch) and anaerobic white muscle (fast-twitch), suggesting thermal compensation. Conclusions We find evidence of widespread transcriptomic differences between the Pacific tuna ventricle and atrium, with potentially higher rates of calcium cycling in the atrium associated with the higher expression of SERCA2b compared to the ventricle. We find no evidence that genes associated with thermogenesis are upregulated in the deep, warm muscle compared to superficial, cool muscle. Heat generation may be enabled by by the high aerobic capacity of bluefin tuna red muscle.
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Affiliation(s)
- Adam Ciezarek
- Department of Life Sciences, Silwood Park Campus, Imperial College London, Ascot, UK. .,Earlham Institute, Norwich Research Park, Norwich, UK.
| | - Luke Gardner
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
| | - Vincent Savolainen
- Department of Life Sciences, Silwood Park Campus, Imperial College London, Ascot, UK
| | - Barbara Block
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
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8
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Abstract
In the 1950s, Arthur C. Guyton removed the heart from its pedestal in cardiovascular physiology by arguing that cardiac output is primarily regulated by the peripheral vasculature. This is counterintuitive, as modulating heart rate would appear to be the most obvious means of regulating cardiac output. In this Review, we visit recent and classic advances in comparative physiology in light of this concept. Although most vertebrates increase heart rate when oxygen demands rise (e.g. during activity or warming), experimental evidence suggests that this tachycardia is neither necessary nor sufficient to drive a change in cardiac output (i.e. systemic blood flow, Q̇ sys) under most circumstances. Instead, Q̇ sys is determined by the interplay between vascular conductance (resistance) and capacitance (which is mainly determined by the venous circulation), with a limited and variable contribution from heart function (myocardial inotropy). This pattern prevails across vertebrates; however, we also highlight the unique adaptations that have evolved in certain vertebrate groups to regulate venous return during diving bradycardia (i.e. inferior caval sphincters in diving mammals and atrial smooth muscle in turtles). Going forward, future investigation of cardiovascular responses to altered metabolic rate should pay equal consideration to the factors influencing venous return and cardiac filling as to the factors dictating cardiac function and heart rate.
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Affiliation(s)
- William Joyce
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark .,Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, ON K1N 6N5, Canada
| | - Tobias Wang
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
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Imbrogno S, Filice M, Cerra MC. Exploring cardiac plasticity in teleost: the role of humoral modulation. Gen Comp Endocrinol 2019; 283:113236. [PMID: 31369729 DOI: 10.1016/j.ygcen.2019.113236] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 07/18/2019] [Accepted: 07/28/2019] [Indexed: 12/01/2022]
Abstract
The fish heart represents an established natural model for evaluating basic mechanisms of the coordinated physiological reactions which maintain cardiac steady-state. This is due to its relatively simple design, but also to its multilevel morpho-functional flexibility which allows adequate responses to a variety of intrinsic (body size and shape, swimming performance, etc.), and extrinsic (temperature, salinity, oxygen level, water chemistry, etc.) factors related to the animal life style. Nowadays, although many gaps are still present, a huge literature is available about the mechanisms that fine-tune fish cardiac performance, particularly in relation to the influence exerted by substances possessing cardio-modulatory properties. Based on these premises, this review will provide an overview of the existing current knowledge regarding the humoral control of cardiac performance in fish. The role of both classic (i.e. catecholamines, angiotensin II and natriuretic peptides), and emerging cardioactive substances (i.e. the chromogranin-A-derived peptides vasostatins, catestatin and serpinin) will be illustrated and discussed. Moreover, an example of cardiomodulation elicited by peptides (e.g., nesfatin-1) associated to the regulation of feeding and metabolism will be provided. The picture will hopefully emphasize the complex circuits that sustain fish cardiac performance, also highliting the power of the teleost heart as an experimental model to deciphering mechanisms that could be difficult to explore in more elaborated cardiac morpho-functional designs.
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Affiliation(s)
- Sandra Imbrogno
- Dept of Biology, Ecology and Earth Sciences (BEST), University of Calabria, 87030, Arcavacata di Rende, CS, Italy
| | - Mariacristina Filice
- Dept of Biology, Ecology and Earth Sciences (BEST), University of Calabria, 87030, Arcavacata di Rende, CS, Italy
| | - Maria Carmela Cerra
- Dept of Biology, Ecology and Earth Sciences (BEST), University of Calabria, 87030, Arcavacata di Rende, CS, Italy
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10
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Heuer RM, Galli GLJ, Shiels HA, Fieber LA, Cox GK, Mager EM, Stieglitz JD, Benetti DD, Grosell M, Crossley Ii DA. Impacts of Deepwater Horizon Crude Oil on Mahi-Mahi ( Coryphaena hippurus) Heart Cell Function. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:9895-9904. [PMID: 31343865 DOI: 10.1021/acs.est.9b03798] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Deepwater Horizon crude oil is comprised of polycyclic aromatic hydrocarbons that cause a number of cardiotoxic effects in marine fishes across all levels of biological organization and at different life stages. Although cardiotoxic impacts have been widely reported, the mechanisms underlying these impairments in adult fish remain understudied. In this study, we examined the impacts of crude oil on cardiomyocyte contractility and electrophysiological parameters in freshly isolated ventricular cardiomyocytes from adult mahi-mahi (Coryphaena hippurus). Cardiomyocytes directly exposed to oil exhibited reduced contractility over a range of environmentally relevant concentrations (2.8-12.9 μg l-1∑PAH). This reduction in contractility was most pronounced at higher stimulation frequencies, corresponding to the upper limits of previously measured in situ mahi heart rates. To better understand the mechanisms underlying impaired contractile function, electrophysiological studies were performed, which revealed oil exposure prolonged cardiomyocyte action potentials and disrupted potassium cycling (9.9-30.4 μg l-1∑PAH). This study is the first to measure cellular contractility in oil-exposed cardiomyocytes from a pelagic fish. Results from this study contribute to previously observed impairments to heart function and whole-animal exercise performance in mahi, underscoring the advantages of using an integrative approach in examining mechanisms of oil-induced cardiotoxicity in marine fish.
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Affiliation(s)
- Rachael M Heuer
- Department of Biological Sciences , University of North Texas , 1511 W. Sycamore Street , Denton Texas 76203 , United States
- Department of Marine Biology and Ecology , University of Miami Rosenstiel School of Marine and Atmospheric Science , 4600 Rickenbacker Causeway , Miami , Florida 33149 , United States
| | - Gina L J Galli
- University of Manchester, Faculty of Biology, Medicine and Health Sciences , The University of Manchester, Core Technology Facility , Grafton Street , Manchester M13 9PL , U.K
| | - Holly A Shiels
- University of Manchester, Faculty of Biology, Medicine and Health Sciences , The University of Manchester, Core Technology Facility , Grafton Street , Manchester M13 9PL , U.K
| | - Lynne A Fieber
- Department of Marine Biology and Ecology , University of Miami Rosenstiel School of Marine and Atmospheric Science , 4600 Rickenbacker Causeway , Miami , Florida 33149 , United States
| | - Georgina K Cox
- Department of Marine Biology and Ecology , University of Miami Rosenstiel School of Marine and Atmospheric Science , 4600 Rickenbacker Causeway , Miami , Florida 33149 , United States
- Department of Integrative Biology , University of Guelph , 50 Stone Road East , Guelph , Ontario Canada , N1G 2W1
| | - Edward M Mager
- Department of Biological Sciences , University of North Texas , 1511 W. Sycamore Street , Denton Texas 76203 , United States
- Department of Marine Biology and Ecology , University of Miami Rosenstiel School of Marine and Atmospheric Science , 4600 Rickenbacker Causeway , Miami , Florida 33149 , United States
| | - John D Stieglitz
- Department of Marine Ecosystems and Society , University of Miami Rosenstiel School of Marine and Atmospheric Science , 4600 Rickenbacker Causeway , Miami , Florida 33149 , United States
| | - Daniel D Benetti
- Department of Marine Ecosystems and Society , University of Miami Rosenstiel School of Marine and Atmospheric Science , 4600 Rickenbacker Causeway , Miami , Florida 33149 , United States
| | - Martin Grosell
- Department of Marine Biology and Ecology , University of Miami Rosenstiel School of Marine and Atmospheric Science , 4600 Rickenbacker Causeway , Miami , Florida 33149 , United States
| | - Dane A Crossley Ii
- Department of Biological Sciences , University of North Texas , 1511 W. Sycamore Street , Denton Texas 76203 , United States
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11
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Badr A, Abu-Amra ES, El-Sayed MF, Vornanen M. Electrical excitability of roach (Rutilus rutilus) ventricular myocytes: effects of extracellular K+, temperature, and pacing frequency. Am J Physiol Regul Integr Comp Physiol 2018; 315:R303-R311. [DOI: 10.1152/ajpregu.00436.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Exercise, capture, and handling stress in fish can elevate extracellular K+ concentration ([K+]o) with potential impact on heart function in a temperature- and frequency-dependent manner. To this end, the effects of [K+]o on the excitability of ventricular myocytes of winter-acclimatized roach ( Rutilus rutilus) (4 ± 0.5°C) were examined at different test temperatures and varying pacing rates. Frequencies corresponding to in vivo heart rates at 4°C (0.37 Hz), 14°C (1.16 Hz), and 24°C (1.96 Hz) had no significant effect on the excitability of ventricular myocytes. Acute increase of temperature from 4 to 14°C did not affect excitability, but a further rise to 24 markedly decreased excitability: stimulus current and critical depolarization needed to elicit an action potential (AP) were ~25 and 14% higher, respectively, at 24°C than at 4°C and 14°C ( P < 0.05). This depression could be due to temperature-related mismatch between inward Na+ and outward K+ currents. In contrast, an increase of [K+]o from 3 to 5.4 or 8 mM at 24°C reduced the stimulus current needed to trigger AP. However, other aspects of excitability were strongly depressed by high [K+]o: maximum rate of AP upstroke and AP duration were drastically (89 and 50%, respectively) reduced at 8 mM [K+]o in comparison with 3 mM ( P < 0.05). As an extreme case, some myocytes completely failed to elicit all-or-none AP at 8 mM [K+]o at 24°C. Also, amplitude and overshoot of AP were reduced by elevation of [K+]o ( P < 0.05). Although high [K+]o antagonizes the negative effects of high temperature on excitation threshold, the precipitous depression of the rate of AP upstroke and complete loss of excitability in some myocytes suggest that the combination of high temperature and high [K+]o will severely impair ventricular excitability in roach.
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Affiliation(s)
- Ahmed Badr
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
- Department of Zoology, Faculty of Science, Sohag University, Sohag, Egypt
| | - El-Sabry Abu-Amra
- Department of Zoology, Faculty of Science, Sohag University, Sohag, Egypt
| | | | - Matti Vornanen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
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12
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Haverinen J, Hassinen M, Dash SN, Vornanen M. Expression of calcium channel transcripts in the zebrafish heart: dominance of T-type channels. ACTA ACUST UNITED AC 2018; 221:jeb.179226. [PMID: 29739832 DOI: 10.1242/jeb.179226] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 04/06/2018] [Indexed: 12/13/2022]
Abstract
Calcium channels are necessary for cardiac excitation-contraction (E-C) coupling, but Ca2+ channel composition of fish hearts is still largely unknown. To this end, we determined transcript expression of Ca2+ channels in the heart of zebrafish (Danio rerio), a popular model species. Altogether, 18 Ca2+ channel α-subunit genes were expressed in both atrium and ventricle. Transcripts for 7 L-type (Cav1.1a, Cav1.1b, Cav1.2, Cav1.3a, Cav1.3b, Cav1.4a, Cav1.4b), 5 T-type (Cav3.1, Cav3.2a, Cav3.2b, Cav3.3a, Cav3.3b) and 6 P/Q-, N- and R-type (Cav2.1a, Cav2.1b, Cav2.2a, Cav2.2b, Cav2.3a, Cav2.3b) Ca2+ channels were expressed. In the ventricle, T-type channels formed 54.9%, L-type channels 41.1% and P/Q-, N- and R-type channels 4.0% of the Ca2+ channel transcripts. In the atrium, the relative expression of T-type and L-type Ca2+ channel transcripts was 64.1% and 33.8%, respectively (others accounted for 2.1%). Thus, at the transcript level, T-type Ca2+ channels are prevalent in zebrafish atrium and ventricle. At the functional level, peak densities of ventricular T-type (ICaT) and L-type (ICaL) Ca2+ current were 6.3±0.8 and 7.7±0.8 pA pF-1, respectively. ICaT mediated a sizeable sarcolemmal Ca2+ influx into ventricular myocytes: the increment in total cellular Ca2+ content via ICaT was 41.2±7.3 µmol l-1, which was 31.7% of the combined Ca2+ influx (129 µmol l-1) via ICaT and ICaL (88.5±20.5 µmol l-1). The diversity of expressed Ca2+ channel genes in zebrafish heart is high, but dominated by the members of the T-type subfamily. The large ventricular ICaT is likely to play a significant role in E-C coupling.
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Affiliation(s)
- Jaakko Haverinen
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 111, 80101 Joensuu, Finland
| | - Minna Hassinen
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 111, 80101 Joensuu, Finland
| | - Surjya Narayan Dash
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 111, 80101 Joensuu, Finland.,Neuroscience Center and Department of Anatomy, Faculty of Medicine, University of Helsinki, PO Box 63, 00014 Helsinki, Finland
| | - Matti Vornanen
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 111, 80101 Joensuu, Finland
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Williams SM, Holmes BJ, Tracey SR, Pepperell JG, Domeier ML, Bennett MB. Environmental influences and ontogenetic differences in vertical habitat use of black marlin ( Istiompax indica) in the southwestern Pacific. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170694. [PMID: 29291060 PMCID: PMC5717634 DOI: 10.1098/rsos.170694] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 09/28/2017] [Indexed: 06/07/2023]
Abstract
The black marlin (Istiompax indica) is a highly migratory billfish that occupies waters throughout the tropical and subtropical Indo-Pacific. To characterize the vertical habitat use of I. indica, we examined the temperature-depth profiles collected using 102 pop-up satellite archival tags deployed off the east coast of Australia. Modelling of environmental variables revealed location, sea-surface height deviation, mixed layer depth and dissolved oxygen to all be significant predictors of vertical habitat use. Distinct differences in diel movements were observed between the size classes, with larger size classes of marlin (greater than 50 kg) undertaking predictable bounce-diving activity during daylight hours, while diving behaviour of the smallest size class occurred randomly during both day and night. Overall, larger size classes of I. indica were found to use an increased thermal range and spend more time in waters below 150 m than fish of smaller size classes. The differences in the diving behaviour among size classes were suggested to reflect ontogenetic differences in foraging behaviour or physiology. The findings of this study demonstrate, for the first time to our knowledge, ontogenetic differences in vertical habitat in a species of billfish, and further the understanding of pelagic fish ecophysiology in the presence of global environmental change.
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Affiliation(s)
- Samuel M. Williams
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Bonnie J. Holmes
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Sean R. Tracey
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 49, Hobart, Tasmania 7001, Australia
| | - Julian G. Pepperell
- Pepperell Research and Consulting Pty Ltd, P.O. Box 1475, Noosaville DC, Queensland 4566, Australia
| | | | - Michael B. Bennett
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia
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14
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Badr A, Hassinen M, El-Sayed MF, Vornanen M. Effects of seasonal acclimatization on action potentials and sarcolemmal K+ currents in roach (Rutilus rutilus) cardiac myocytes. Comp Biochem Physiol A Mol Integr Physiol 2017; 205:15-27. [DOI: 10.1016/j.cbpa.2016.12.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 12/13/2016] [Accepted: 12/15/2016] [Indexed: 01/10/2023]
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15
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16
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Vornanen M. Electrical Excitability of the Fish Heart and Its Autonomic Regulation. FISH PHYSIOLOGY 2017. [DOI: 10.1016/bs.fp.2017.04.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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17
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Keen AN, Klaiman JM, Shiels HA, Gillis TE. Temperature-induced cardiac remodelling in fish. ACTA ACUST UNITED AC 2016; 220:147-160. [PMID: 27852752 PMCID: PMC5278617 DOI: 10.1242/jeb.128496] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Thermal acclimation causes the heart of some fish species to undergo significant remodelling. This includes changes in electrical activity, energy utilization and structural properties at the gross and molecular level of organization. The purpose of this Review is to summarize the current state of knowledge of temperature-induced structural remodelling in the fish ventricle across different levels of biological organization, and to examine how such changes result in the modification of the functional properties of the heart. The structural remodelling response is thought to be responsible for changes in cardiac stiffness, the Ca2+ sensitivity of force generation and the rate of force generation by the heart. Such changes to both active and passive properties help to compensate for the loss of cardiac function caused by a decrease in physiological temperature. Hence, temperature-induced cardiac remodelling is common in fish that remain active following seasonal decreases in temperature. This Review is organized around the ventricular phases of the cardiac cycle – specifically diastolic filling, isovolumic pressure generation and ejection – so that the consequences of remodelling can be fully described. We also compare the thermal acclimation-associated modifications of the fish ventricle with those seen in the mammalian ventricle in response to cardiac pathologies and exercise. Finally, we consider how the plasticity of the fish heart may be relevant to survival in a climate change context, where seasonal temperature changes could become more extreme and variable. Summary: Thermal acclimation of some temperate fishes causes extensive remodelling of the heart. The resultant changes to the active and passive properties of the heart represent a highly integrated phenotypic response.
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Affiliation(s)
- Adam N Keen
- Division of Cardiovascular Science, School of Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9NT, UK
| | - Jordan M Klaiman
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA 98109, USA
| | - Holly A Shiels
- Division of Cardiovascular Science, School of Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9NT, UK
| | - Todd E Gillis
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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18
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Nelson D, Heuer RM, Cox GK, Stieglitz JD, Hoenig R, Mager EM, Benetti DD, Grosell M, Crossley DA. Effects of crude oil on in situ cardiac function in young adult mahi-mahi (Coryphaena hippurus). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2016; 180:274-281. [PMID: 27768947 DOI: 10.1016/j.aquatox.2016.10.012] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 10/11/2016] [Accepted: 10/13/2016] [Indexed: 05/25/2023]
Abstract
Exposure to polycyclic aromatic hydrocarbons (PAH) negatively impacts exercise performance in fish species but the physiological modifications that result in this phenotype are poorly understood. Prior studies have shown that embryonic and juvenile mahi-mahi (Coryphaeus hippurus) exposed to PAH exhibit morphological abnormalities, altered cardiac development and reduced swimming performance. It has been suggested that cardiovascular function inhibited by PAH exposure accounts for the compromised exercise performance in fish species. In this study we used in-situ techniques to measure hemodynamic responses of young adult mahi-mahi exposed to PAH for 24h. The data indicate that stroke volume was reduced 44% in mahi-mahi exposed to 9.6±2.7μgl-1 geometric mean PAH (∑PAH) and resulted in a 39% reduction in cardiac output and a 52% reduction in stroke work. Maximal change in pressure over change in time was 28% lower in mahi-mahi exposed to this level of ∑PAH. Mean intraventricular pressures and heart rate were not significantly changed. This study suggests exposure to environmentally relevant PAH concentrations impairs aspects of cardiovascular function in mahi-mahi.
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Affiliation(s)
- Derek Nelson
- University of North Texas, Department of Biological Sciences 1155 Union Circle Denton, TX 76203, United States
| | - Rachael M Heuer
- University of North Texas, Department of Biological Sciences 1155 Union Circle Denton, TX 76203, United States
| | - Georgina K Cox
- Division of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Miami, FL 33149-1098, United States
| | - John D Stieglitz
- Division of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Miami, FL 33149-1098, United States
| | - Ronald Hoenig
- Division of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Miami, FL 33149-1098, United States
| | - Edward M Mager
- Division of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Miami, FL 33149-1098, United States
| | - Daniel D Benetti
- Division of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Miami, FL 33149-1098, United States
| | - Martin Grosell
- Division of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Miami, FL 33149-1098, United States
| | - Dane A Crossley
- University of North Texas, Department of Biological Sciences 1155 Union Circle Denton, TX 76203, United States.
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19
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Vornanen M. The temperature dependence of electrical excitability in fish hearts. J Exp Biol 2016; 219:1941-52. [DOI: 10.1242/jeb.128439] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 05/17/2016] [Indexed: 01/08/2023]
Abstract
ABSTRACT
Environmental temperature has pervasive effects on the rate of life processes in ectothermic animals. Animal performance is affected by temperature, but there are finite thermal limits for vital body functions, including contraction of the heart. This Review discusses the electrical excitation that initiates and controls the rate and rhythm of fish cardiac contraction and is therefore a central factor in the temperature-dependent modulation of fish cardiac function. The control of cardiac electrical excitability should be sensitive enough to respond to temperature changes but simultaneously robust enough to protect against cardiac arrhythmia; therefore, the thermal resilience and plasticity of electrical excitation are physiological qualities that may affect the ability of fishes to adjust to climate change. Acute changes in temperature alter the frequency of the heartbeat and the duration of atrial and ventricular action potentials (APs). Prolonged exposure to new thermal conditions induces compensatory changes in ion channel expression and function, which usually partially alleviate the direct effects of temperature on cardiac APs and heart rate. The most heat-sensitive molecular components contributing to the electrical excitation of the fish heart seem to be Na+ channels, which may set the upper thermal limit for the cardiac excitability by compromising the initiation of the cardiac AP at high temperatures. In cardiac and other excitable cells, the different temperature dependencies of the outward K+ current and inward Na+ current may compromise electrical excitability at temperature extremes, a hypothesis termed the temperature-dependent depression of electrical excitation.
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Affiliation(s)
- Matti Vornanen
- University of Eastern Finland, Department of Environmental and Biological Sciences, PO Box 111, Joensuu 80101, Finland
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20
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Horodysky AZ, Cooke SJ, Graves JE, Brill RW. Fisheries conservation on the high seas: linking conservation physiology and fisheries ecology for the management of large pelagic fishes. CONSERVATION PHYSIOLOGY 2016; 4:cov059. [PMID: 27382467 PMCID: PMC4922246 DOI: 10.1093/conphys/cov059] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 11/09/2015] [Accepted: 11/15/2015] [Indexed: 05/26/2023]
Abstract
Populations of tunas, billfishes and pelagic sharks are fished at or over capacity in many regions of the world. They are captured by directed commercial and recreational fisheries (the latter of which often promote catch and release) or as incidental catch or bycatch in commercial fisheries. Population assessments of pelagic fishes typically incorporate catch-per-unit-effort time-series data from commercial and recreational fisheries; however, there have been notable changes in target species, areas fished and depth-specific gear deployments over the years that may have affected catchability. Some regional fisheries management organizations take into account the effects of time- and area-specific changes in the behaviours of fish and fishers, as well as fishing gear, to standardize catch-per-unit-effort indices and refine population estimates. However, estimates of changes in stock size over time may be very sensitive to underlying assumptions of the effects of oceanographic conditions and prey distribution on the horizontal and vertical movement patterns and distribution of pelagic fishes. Effective management and successful conservation of pelagic fishes requires a mechanistic understanding of their physiological and behavioural responses to environmental variability, potential for interaction with commercial and recreational fishing gear, and the capture process. The interdisciplinary field of conservation physiology can provide insights into pelagic fish demography and ecology (including environmental relationships and interspecific interactions) by uniting the complementary expertise and skills of fish physiologists and fisheries scientists. The iterative testing by one discipline of hypotheses generated by the other can span the fundamental-applied science continuum, leading to the development of robust insights supporting informed management. The resulting species-specific understanding of physiological abilities and tolerances can help to improve stock assessments, develop effective bycatch-reduction strategies, predict rates of post-release mortality, and forecast the population effects of environmental change. In this synthesis, we review several examples of these interdisciplinary collaborations that currently benefit pelagic fisheries management.
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Affiliation(s)
- Andrij Z. Horodysky
- Department of Marine and Environmental Science, Hampton University, 100 East Queen Street, Hampton, VA 23668, USA
| | - Steven J. Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental Science, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada K1S 5B6
| | - John E. Graves
- Department of Fisheries Science, Virginia Institute of Marine Science, College of William & Mary, Gloucester Point, VA 23062, USA
| | - Richard W. Brill
- Department of Fisheries Science, Virginia Institute of Marine Science, College of William & Mary, Gloucester Point, VA 23062, USA
- Behavioral Ecology Branch, James J. Howard Marine Sciences Laboratory, Northeast Fisheries Science Center, National Marine Fisheries Service, NOAA, Highlands, NJ 07732, USA
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21
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Kubly KL, Stecyk JAW. Temperature-dependence of L-type Ca(2+) current in ventricular cardiomyocytes of the Alaska blackfish (Dallia pectoralis). J Comp Physiol B 2015; 185:845-58. [PMID: 26439127 DOI: 10.1007/s00360-015-0931-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 08/04/2015] [Accepted: 09/07/2015] [Indexed: 01/12/2023]
Abstract
To lend insight into the overwintering strategy of the Alaska blackfish (Dallia pectoralis), we acclimated fish to 15 or 5 °C and then utilized whole-cell patch clamp to characterize the effects of thermal acclimation and acute temperature change on the density and kinetics of ventricular L-type Ca(2+) current (I Ca). Peak I Ca density at 5 °C (-1.1 ± 0.1 pA pF(-1)) was 1/8th that at 15 °C (-8.8 ± 0.6 pA pF(-1)). However, alterations of the Ca(2+)- and voltage-dependent inactivation properties of L-type Ca(2+) channels partially compensated against the decrease. The time constant tau (τ) for the kinetics of inactivation of I Ca was ~4.5 times greater at 5 °C than at 15 °C, and the voltage for half-maximal inactivation was shifted from -23.3 ± 1.0 mV at 15 °C to -19.8 ± 1.2 mV at 5 °C. These modifications increase the open probability of the channel and culminate in an approximate doubling of the L-type Ca(2+) window current, which contributes to approximately 15% of the maximal Ca(2+) conductance at 5 °C. Consequently, the charge density of I Ca (Q Ca) and the total Ca(2+) transferred through the L-type Ca(2+) channels (Δ[Ca(2+)]) were not as severely reduced at 5 °C as compared to peak I Ca density. In combination, the results suggest that while the Alaska blackfish substantially down-regulates I Ca with acclimation to low temperature, there is sufficient compensation in the kinetics of the L-type Ca(2+) channel to support the level of cardiac performance required for the fish to remain active throughout the winter.
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Affiliation(s)
- Kerry L Kubly
- Department of Biological Sciences, University of Alaska Anchorage, 3211 Providence Drive, Conoco Philips Integrated Science Building, Anchorage, AK, 99508, USA.
| | - Jonathan A W Stecyk
- Department of Biological Sciences, University of Alaska Anchorage, 3211 Providence Drive, Conoco Philips Integrated Science Building, Anchorage, AK, 99508, USA
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22
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Whitlock RE, Hazen EL, Walli A, Farwell C, Bograd SJ, Foley DG, Castleton M, Block BA. Direct quantification of energy intake in an apex marine predator suggests physiology is a key driver of migrations. SCIENCE ADVANCES 2015; 1:e1400270. [PMID: 26601248 PMCID: PMC4643779 DOI: 10.1126/sciadv.1400270] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 07/01/2015] [Indexed: 05/26/2023]
Abstract
Pacific bluefin tuna (Thunnus orientalis) are highly migratory apex marine predators that inhabit a broad thermal niche. The energy needed for migration must be garnered by foraging, but measuring energy intake in the marine environment is challenging. We quantified the energy intake of Pacific bluefin tuna in the California Current using a laboratory-validated model, the first such measurement in a wild marine predator. Mean daily energy intake was highest off the coast of Baja California, Mexico in summer (mean ± SD, 1034 ± 669 kcal), followed by autumn when Pacific bluefin achieve their northernmost range in waters off northern California (944 ± 579 kcal). Movements were not always consistent with maximizing energy intake: the Pacific bluefin move out of energy rich waters both in late summer and winter, coincident with rising and falling water temperatures, respectively. We hypothesize that temperature-related physiological constraints drive migration and that Pacific bluefin tuna optimize energy intake within a range of optimal aerobic performance.
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Affiliation(s)
- Rebecca E. Whitlock
- Tuna Research and Conservation Center, Stanford University, Hopkins Marine Station, Oceanview Boulevard, Pacific Grove, CA 93950, USA
- Sveriges Lantbruksuniversitet, Sötvattenslaboratoriet, Stångholmsvägen 2, Drottningholm 178 93, Sweden
| | - Elliott L. Hazen
- Environmental Research Division, Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration (NOAA), 99 Pacific Street, Suite 255A, Monterey, CA 93940, USA
| | - Andreas Walli
- Tuna Research and Conservation Center, Stanford University, Hopkins Marine Station, Oceanview Boulevard, Pacific Grove, CA 93950, USA
| | - Charles Farwell
- Monterey Bay Aquarium, 886 Cannery Row, Monterey Bay, CA 93940, USA
| | - Steven J. Bograd
- Environmental Research Division, Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration (NOAA), 99 Pacific Street, Suite 255A, Monterey, CA 93940, USA
| | - David G. Foley
- Environmental Research Division, Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration (NOAA), 99 Pacific Street, Suite 255A, Monterey, CA 93940, USA
| | - Michael Castleton
- Tuna Research and Conservation Center, Stanford University, Hopkins Marine Station, Oceanview Boulevard, Pacific Grove, CA 93950, USA
| | - Barbara A. Block
- Tuna Research and Conservation Center, Stanford University, Hopkins Marine Station, Oceanview Boulevard, Pacific Grove, CA 93950, USA
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23
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Zhang F, Broughton RE. Heterogeneous natural selection on oxidative phosphorylation genes among fishes with extreme high and low aerobic performance. BMC Evol Biol 2015; 15:173. [PMID: 26306407 PMCID: PMC4549853 DOI: 10.1186/s12862-015-0453-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 08/12/2015] [Indexed: 02/07/2023] Open
Abstract
Background Oxidative phosphorylation (OXPHOS) is the primary source of ATP in eukaryotes and serves as a mechanistic link between variation in genotypes and energetic phenotypes. While several physiological and anatomical factors may lead to increased aerobic capacity, variation in OXPHOS proteins may influence OXPHOS efficiency and facilitate adaptation in organisms with varied energy demands. Although there is evidence that natural selection acts on OXPHOS genes, the focus has been on detection of directional (positive) selection on specific phylogenetic branches where traits that increase energetic demands appear to have evolved. We examined patterns of selection in a broader evolutionary context, i.e., on multiple lineages of fishes with extreme high and low aerobic performance. Results We found that patterns of natural selection on mitochondrial OXPHOS genes are complex among fishes with different swimming performance. Positive selection is not consistently associated with high performance taxa and appears to be strongest on lineages containing low performance taxa. In contrast, within high performance lineages, purifying (negative) selection appears to predominate. Conclusions We provide evidence that selection on OXPHOS varies in both form and intensity within and among lineages through evolutionary time. These results provide evidence for fluctuating selection on OXPHOS associated with divergence in aerobic performance. However, in contrast to previous studies, positive selection was strongest on low performance taxa suggesting that adaptation of OXPHOS involves many factors beyond enhancing ATP production in high performance taxa. The broader pattern indicates a complex interplay between organismal adaptations, ATP demand, and OXPHOS function. Electronic supplementary material The online version of this article (doi:10.1186/s12862-015-0453-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Feifei Zhang
- Oklahoma Biological Survey and Department of Biology, University of Oklahoma, 111 E Chesapeake Street, Norman, OK, 73019, USA.
| | - Richard E Broughton
- Oklahoma Biological Survey and Department of Biology, University of Oklahoma, 111 E Chesapeake Street, Norman, OK, 73019, USA.
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Joyce W, Simonsen M, Gesser H, Wang T. The effects of hypoxic bradycardia and extracellular HCO3−/CO2 on hypoxic performance in the eel heart. J Exp Biol 2015; 219:302-5. [DOI: 10.1242/jeb.130971] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 11/16/2015] [Indexed: 10/22/2022]
Abstract
During hypoxia fishes exhibit a characteristic ‘hypoxic bradycardia’, the functional significance of which remains debated. Here, we investigated the hypothesis that hypoxic bradycardia primarily safeguards cardiac performance. In preparations from the European eel (Anguilla anguilla), a decrease in stimulation frequency from 40 to 15 beats per minute, which replicates hypoxic bradycardia in vivo, vastly improved cardiac performance during hypoxia in vitro. As eels display dramatic shifts in extracellular HCO3−/CO2, we further investigated the effect this has upon hypoxic cardiac performance. Elevations from 10 mM HCO3−/ 1% to 40 mM HCO3−/ 4% CO2 had few effects on performance, however further, but still physiologically relevant, increases to 70 mM HCO3−/ 7% CO2 compromised hypoxia tolerance. We revealed a four-way interaction between HCO3−/CO2, contraction frequency, hypoxia and performance over time, whereby the benefit of hypoxic bradycardia was most prolonged at 10 mM HCO3−/ 1% CO2. Together, our data suggest that hypoxic bradycardia greatly benefits cardiac performance, but its significance may be context-specific.
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Affiliation(s)
- William Joyce
- Zoophysiology, Department of Bioscience, Aarhus University, Building 1131, Universitetsparken, 8000 Aarhus C, Denmark
| | - Maj Simonsen
- Zoophysiology, Department of Bioscience, Aarhus University, Building 1131, Universitetsparken, 8000 Aarhus C, Denmark
| | - Hans Gesser
- Zoophysiology, Department of Bioscience, Aarhus University, Building 1131, Universitetsparken, 8000 Aarhus C, Denmark
| | - Tobias Wang
- Zoophysiology, Department of Bioscience, Aarhus University, Building 1131, Universitetsparken, 8000 Aarhus C, Denmark
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