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Molina JM, Kunzmann A, Reis JP, Guerreiro PM. Metabolic Responses and Resilience to Environmental Challenges in the Sedentary Batrachoid Halobatrachus didactylus (Bloch & Schneider, 1801). Animals (Basel) 2023; 13:ani13040632. [PMID: 36830420 PMCID: PMC9951689 DOI: 10.3390/ani13040632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 02/06/2023] [Accepted: 02/10/2023] [Indexed: 02/16/2023] Open
Abstract
In the context of climate change, warming of the seas and expansion of hypoxic zones are challenges that most species of fish are, or will be subjected to. Understanding how different species cope with these changes in their environment at the individual level can shed light on how populations and ecosystems will be affected. We provide first-time estimates on the metabolic rates, thermal, and oxygen-related limits for Halobatrachus didactylus, a coastal sedentary fish that lives in intertidal environments of the Northeast Atlantic. Using respirometry in different experimental designs, we found that this species is highly resistant to acute thermal stress (CTmax: 34.82 ± 0.66 °C) and acute hypoxia (Pcrit: 0.59-1.97 mg O2 L-1). We found size-specific differences in this stress response, with smaller individuals being more sensitive. We also quantified its aerobic scope and daily activity patterns, finding this fish to be extremely sedentary, with one of the lowest standard metabolic rates found in temperate fish (SMR: 14.96 mg O2 kg-1h-1). H. didactylus activity increases at night, when its metabolic rate increases drastically (RMR: 36.01 mg O2 kg-1h-1). The maximum metabolic rate of H. didactylus was estimated to be 67.31 mg O2 kg-1h-1, producing an aerobic scope of 52.35 mg O2 kg-1h-1 (77.8% increase). The metrics obtained in this study prove that H. didactylus is remarkably resilient to acute environmental variations in temperature and oxygen content, which might enable it to adapt to the extreme abiotic conditions forecasted for the world's oceans in the near future.
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Affiliation(s)
- Juan Manuel Molina
- Instituto Argentino de Oceanografía (CONICET), Bahía Blanca B8000, Argentina
- Leibniz-Zentrum für Marine Tropenforschung (ZMT), 28359 Bremen, Germany
- Centro de Ciências do Mar (CCMAR), Universidade do Algarve, 8005-139 Faro, Portugal
- Correspondence:
| | - Andreas Kunzmann
- Leibniz-Zentrum für Marine Tropenforschung (ZMT), 28359 Bremen, Germany
| | - João Pena Reis
- Centro de Ciências do Mar (CCMAR), Universidade do Algarve, 8005-139 Faro, Portugal
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Killen SS, Christensen EAF, Cortese D, Závorka L, Norin T, Cotgrove L, Crespel A, Munson A, Nati JJH, Papatheodoulou M, McKenzie DJ. Guidelines for reporting methods to estimate metabolic rates by aquatic intermittent-flow respirometry. J Exp Biol 2021; 224:jeb242522. [PMID: 34520540 PMCID: PMC8467026 DOI: 10.1242/jeb.242522] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Interest in the measurement of metabolic rates is growing rapidly, because of the importance of metabolism in advancing our understanding of organismal physiology, behaviour, evolution and responses to environmental change. The study of metabolism in aquatic animals is undergoing an especially pronounced expansion, with more researchers utilising intermittent-flow respirometry as a research tool than ever before. Aquatic respirometry measures the rate of oxygen uptake as a proxy for metabolic rate, and the intermittent-flow technique has numerous strengths for use with aquatic animals, allowing metabolic rate to be repeatedly estimated on individual animals over several hours or days and during exposure to various conditions or stimuli. There are, however, no published guidelines for the reporting of methodological details when using this method. Here, we provide the first guidelines for reporting intermittent-flow respirometry methods, in the form of a checklist of criteria that we consider to be the minimum required for the interpretation, evaluation and replication of experiments using intermittent-flow respirometry. Furthermore, using a survey of the existing literature, we show that there has been incomplete and inconsistent reporting of methods for intermittent-flow respirometry over the past few decades. Use of the provided checklist of required criteria by researchers when publishing their work should increase consistency of the reporting of methods for studies that use intermittent-flow respirometry. With the steep increase in studies using intermittent-flow respirometry, now is the ideal time to standardise reporting of methods, so that - in the future - data can be properly assessed by other scientists and conservationists.
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Affiliation(s)
- Shaun S. Killen
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ, UK
| | - Emil A. F. Christensen
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ, UK
| | - Daphne Cortese
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ, UK
- PSL Université Paris: EPHE-UPVD-CNRS, USR 3278 CRIOBE, BP 1013, 98729 Papetoai, Moorea, French Polynesia
| | - Libor Závorka
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ, UK
- WasserCluster Lunz–Inter-university Centre for Aquatic Ecosystem Research, A-3293 Lunz am See, Austria
| | - Tommy Norin
- DTU Aqua: National Institute of Aquatic Resources, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Lucy Cotgrove
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ, UK
| | - Amélie Crespel
- Department of Biology, University of Turku, 20500 Turku, Finland
| | - Amelia Munson
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ, UK
- Department of Environmental Science and Policy, University of California, Davis, CA 95615, USA
| | - Julie J. H. Nati
- MARBEC, Université Montpellier, CNRS, Ifremer, IRD, 34000 Montpellier, France
| | - Magdalene Papatheodoulou
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ, UK
- Enalia Physis Environmental Research Centre (ENALIA), 2101 Nicosia, Cyprus
| | - David J. McKenzie
- MARBEC, Université Montpellier, CNRS, Ifremer, IRD, 34000 Montpellier, France
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Seibel BA, Andres A, Birk MA, Burns AL, Shaw CT, Timpe AW, Welsh CJ. Oxygen supply capacity breathes new life into critical oxygen partial pressure (Pcrit). J Exp Biol 2021; 224:jeb.242210. [PMID: 33692079 DOI: 10.1242/jeb.242210] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 03/01/2021] [Indexed: 12/11/2022]
Abstract
The critical oxygen partial pressure (Pcrit), typically defined as the PO2 below which an animal's metabolic rate (MR) is unsustainable, is widely interpreted as a measure of hypoxia tolerance. Here, Pcrit is defined as the PO2 at which physiological oxygen supply (α0) reaches its maximum capacity (α; µmol O2 g-1 h-1 kPa-1). α is a species- and temperature-specific constant describing the oxygen dependency of the maximum metabolic rate (MMR=PO2×α) or, equivalently, the MR dependence of Pcrit (Pcrit=MR/α). We describe the α-method, in which the MR is monitored as oxygen declines and, for each measurement period, is divided by the corresponding PO2 to provide the concurrent oxygen supply (α0=MR/PO2). The highest α0 value (or, more conservatively, the mean of the three highest values) is designated as α. The same value of α is reached at Pcrit for any MR regardless of previous or subsequent metabolic activity. The MR need not be constant (regulated), standardized or exhibit a clear breakpoint at Pcrit for accurate determination of α. The α-method has several advantages over Pcrit determination and non-linear analyses, including: (1) less ambiguity and greater accuracy, (2) fewer constraints in respirometry methodology and analysis, and (3) greater predictive power and ecological and physiological insight. Across the species evaluated here, α values are correlated with MR, but not Pcrit. Rather than an index of hypoxia tolerance, Pcrit is a reflection of α, which evolves to support maximum energy demands and aerobic scope at the prevailing temperature and oxygen level.
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Affiliation(s)
- Brad A Seibel
- College of Marine Science, University of South Florida, St Petersburg, FL 33701, USA
| | - Alyssa Andres
- College of Marine Science, University of South Florida, St Petersburg, FL 33701, USA
| | - Matthew A Birk
- College of Marine Science, University of South Florida, St Petersburg, FL 33701, USA
| | - Alexandra L Burns
- College of Marine Science, University of South Florida, St Petersburg, FL 33701, USA
| | - C Tracy Shaw
- College of Marine Science, University of South Florida, St Petersburg, FL 33701, USA
| | - Alexander W Timpe
- College of Marine Science, University of South Florida, St Petersburg, FL 33701, USA
| | - Christina J Welsh
- College of Marine Science, University of South Florida, St Petersburg, FL 33701, USA
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Hasenei A, Kerstetter DW, Horodysky AZ, Brill RW. Physiological limits to inshore invasion of Indo-Pacific lionfish (Pterois spp.): insights from the functional characteristics of their visual system and hypoxia tolerance. Biol Invasions 2020. [DOI: 10.1007/s10530-020-02241-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Wood AT, Andrewartha SJ, Elliott NG, Frappell PB, Clark TD. Hypoxia during incubation does not affect aerobic performance or haematology of Atlantic salmon ( Salmo salar) when re-exposed in later life. CONSERVATION PHYSIOLOGY 2019; 7:coz088. [PMID: 31798884 PMCID: PMC6880253 DOI: 10.1093/conphys/coz088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 08/26/2019] [Accepted: 10/15/2019] [Indexed: 05/26/2023]
Abstract
Hypoxia in aquatic ecosystems is becoming increasingly prevalent, potentially reducing fish performance and survival by limiting the oxygen available for aerobic activities. Hypoxia is a challenge for conserving and managing fish populations and demands a better understanding of the short- and long-term impacts of hypoxic environments on fish performance. Fish acclimate to hypoxia via a variety of short- and long-term physiological modifications in an attempt to maintain aerobic performance. In particular, hypoxia exposure during early development may result in enduring cardio-respiratory modifications that affect future hypoxia acclimation capacity, yet this possibility remains poorly investigated. We incubated Atlantic salmon (Salmo salar) in normoxia (~100% dissolved oxygen [DO, as percent air saturation]), moderate hypoxia (~63% DO) or cyclical hypoxia (100-25% DO daily) from fertilization until 113 days post-fertilization prior to rearing all groups in normoxia for a further 8 months. At ~11 months of age, subsets of each group were acclimated to hypoxia (50% DO) for up to 44 days prior to haematology, aerobic metabolic rate and hypoxia tolerance measurements. Hypoxia exposure during incubation (fertilization to 113 days post-fertilization) did not affect the haematology, aerobic performance or hypoxia tolerance of juvenile salmon in later life. Juveniles acclimated to hypoxia increased maximum aerobic metabolic rate and aerobic scope by ~23 and ~52%, respectively, when measured at 50% DO but not at 100% DO. Hypoxia-incubated juveniles also increased haematocrit and haemoglobin concentration but did not affect acute hypoxia tolerance (critical oxygen level and DO at LOE). Thus, while Atlantic salmon possess a considerable capacity to physiologically acclimate to hypoxia by improving aerobic performance in low oxygen conditions, we found no evidence that this capacity is influenced by early-life hypoxia exposure.
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Affiliation(s)
- Andrew T Wood
- Commonwealth Scientific and Industrial Research Organisation, Agriculture and Food, 3-4 Castray Esplanade, Battery Point, Tasmania 7004, Australia
| | - Sarah J Andrewartha
- Tasmanian Institute of Agriculture, University of Tasmania, Private Bag 98, Hobart, 7001, Australia
| | - Nicholas G Elliott
- Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Tasmania 7004, Australia
| | - Peter B Frappell
- Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Tasmania 7004, Australia
| | - Timothy D Clark
- School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3216, Australia
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6
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Ultsch GR, Regan MD. The utility and determination of P crit in fishes. ACTA ACUST UNITED AC 2019; 222:222/22/jeb203646. [PMID: 31722971 DOI: 10.1242/jeb.203646] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The critical O2 tension (P crit) is the lowest P O2 at which an animal can maintain some benchmark rate of O2 uptake (Ṁ O2 ). This P O2 has long served as a comparator of hypoxia tolerance in fishes and aquatic invertebrates, but its usefulness in this role, particularly when applied to fishes, has recently been questioned. We believe that P crit remains a useful comparator of hypoxia tolerance provided it is determined using the proper methods and hypoxia tolerance is clearly defined. Here, we review the available methods for each of the three steps of P crit determination: (1) measuring the most appropriate benchmark Ṁ O2 state for P crit determination (Ṁ O2,std, the Ṁ O2 required to support standard metabolic rate); (2) reducing water P O2 ; and (3) calculating P crit from the Ṁ O2 versus P O2 curve. We make suggestions on best practices for each step and for how to report P crit results to maximize their comparative value. We also discuss the concept of hypoxia tolerance and how P crit relates to a fish's overall hypoxia tolerance. When appropriate methods are used, P crit provides useful comparative physiological and ecological information about the aerobic contributions to a fish's hypoxic survival. When paired with other hypoxia-related physiological measurements (e.g. lactate accumulation, calorimetry-based measurements of metabolic depression, loss-of-equilibrium experiments), P crit contributes to a comprehensive understanding of how a fish combines aerobic metabolism, anaerobic metabolism and metabolic depression in an overall strategy for hypoxia tolerance.
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Affiliation(s)
- Gordon R Ultsch
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Matthew D Regan
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706, USA
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7
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Negrete B, Esbaugh AJ. A methodological evaluation of the determination of critical oxygen threshold in an estuarine teleost. Biol Open 2019; 8:bio.045310. [PMID: 31649119 PMCID: PMC6899028 DOI: 10.1242/bio.045310] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
One measure of hypoxia tolerance is the critical oxygen threshold, Pcrit, which is the point where standard metabolism can no longer be maintained through aerobic processes. Traditionally, Pcrit was determined using closed respirometry, whereby the fish's respiration naturally lowered O2. More recently, intermittent flow techniques have been adopted, where N2 is used to displace O2, which ostensibly reduces end-product build-up. This study used a paired design on the marine teleost, red drum. Pcrit is comparable between closed (4.6±0.2 kPa; mean±s.e.m.) and intermittent flow (4.4±0.2 kPa; mean±s.e.m.) respirometry. pCO2, ammonia and pH changes within the chamber were measured prior to the onset of Pcrit and at the end of a typical Pcrit trial and revealed changes in water chemistry in both closed and intermittent flow. Pcrit values were similar in both methods of hypoxia induction regardless of subsequent water chemistry changes that occurred in both methods. Summary: The two leading methods of measuring the critical oxygen threshold in fishes are similar in their estimations, regardless of changes to water chemistry.
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Affiliation(s)
- Benjamin Negrete
- Department of Marine Science, Marine Science Institute, The University of Texas at Austin, Port Aransas, TX 78373, USA
| | - Andrew J Esbaugh
- Department of Marine Science, Marine Science Institute, The University of Texas at Austin, Port Aransas, TX 78373, USA
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8
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Burggren WW, Arriaga-Bernal JC, Méndez-Arzate PM, Méndez-Sánchez JF. Metabolic physiology of the Mayan cichlid fish (Mayaheros uropthalmus): Re-examination of classification as an oxyconformer. Comp Biochem Physiol A Mol Integr Physiol 2019; 237:110538. [DOI: 10.1016/j.cbpa.2019.110538] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 08/05/2019] [Accepted: 08/07/2019] [Indexed: 11/16/2022]
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9
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Montgomery DW, Simpson SD, Engelhard GH, Birchenough SNR, Wilson RW. Rising CO 2 enhances hypoxia tolerance in a marine fish. Sci Rep 2019; 9:15152. [PMID: 31641181 PMCID: PMC6805886 DOI: 10.1038/s41598-019-51572-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 09/25/2019] [Indexed: 11/09/2022] Open
Abstract
Global environmental change is increasing hypoxia in aquatic ecosystems. During hypoxic events, bacterial respiration causes an increase in carbon dioxide (CO2) while oxygen (O2) declines. This is rarely accounted for when assessing hypoxia tolerances of aquatic organisms. We investigated the impact of environmentally realistic increases in CO2 on responses to hypoxia in European sea bass (Dicentrarchus labrax). We conducted a critical oxygen (O2crit) test, a common measure of hypoxia tolerance, using two treatments in which O2 levels were reduced with constant ambient CO2 levels (~530 µatm), or with reciprocal increases in CO2 (rising to ~2,500 µatm). We also assessed blood acid-base chemistry and haemoglobin-O2 binding affinity of sea bass in hypoxic conditions with ambient (~650 μatm) or raised CO2 (~1770 μatm) levels. Sea bass exhibited greater hypoxia tolerance (~20% reduced O2crit), associated with increased haemoglobin-O2 affinity (~32% fall in P50) of red blood cells, when exposed to reciprocal changes in O2 and CO2. This indicates that rising CO2 which accompanies environmental hypoxia facilitates increased O2 uptake by the blood in low O2 conditions, enhancing hypoxia tolerance. We recommend that when impacts of hypoxia on aquatic organisms are assessed, due consideration is given to associated environmental increases in CO2.
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Affiliation(s)
- Daniel W Montgomery
- Bioscience Department, College of Life and Environmental Sciences, University of Exeter, Exeter, UK.
| | - Stephen D Simpson
- Bioscience Department, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Georg H Engelhard
- Centre for Environment, Fisheries & Aquaculture Science (Cefas), Pakefield Road, Lowestoft, NR33 0HT, UK
- School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Silvana N R Birchenough
- Centre for Environment, Fisheries & Aquaculture Science (Cefas), Pakefield Road, Lowestoft, NR33 0HT, UK
| | - Rod W Wilson
- Bioscience Department, College of Life and Environmental Sciences, University of Exeter, Exeter, UK.
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10
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Reemeyer JE, Rees BB. Standardizing the determination and interpretation of P crit in fishes. ACTA ACUST UNITED AC 2019; 222:jeb.210633. [PMID: 31511343 DOI: 10.1242/jeb.210633] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 09/06/2019] [Indexed: 12/30/2022]
Abstract
The critical oxygen tension (P crit) for fishes is the oxygen level below which the rate of oxygen consumption (Ṁ O2 ) becomes dependent upon ambient oxygen partial pressure (P O2 ). We compare multiple curve-fitting approaches to estimate P crit of the Gulf killifish, Fundulus grandis, during closed and intermittent-flow respirometry. Fitting two line segments of Ṁ O2 versus P O2 produced high and variable estimates of P crit, as did nonlinear regression using a hyperbolic (Michaelis-Menten) function. Using nonlinear regression fit to an exponential (modified Weibull) function, or linear regression of Ṁ O2 versus P O2 at low P O2 , and determining P crit as the P O2 when Ṁ O2 equals standard metabolic rate (SMR) yielded values that were consistent across fish and among experimental trials. The magnitude of the difference in P crit determined by alternative calculation methods exceeded the differences determined in closed and intermittent-flow respirometry, highlighting the need to standardize analytical as well as experimental approaches in determining P crit.
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Affiliation(s)
- Jessica E Reemeyer
- Department of Biological Sciences, University of New Orleans, New Orleans, LA 70148, USA
| | - Bernard B Rees
- Department of Biological Sciences, University of New Orleans, New Orleans, LA 70148, USA
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11
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Nelson JA, Kraskura K, Lipkey GK. Repeatability of Hypoxia Tolerance of Individual Juvenile Striped Bass Morone saxatilis and Effects of Social Status. Physiol Biochem Zool 2019; 92:396-407. [PMID: 31141466 DOI: 10.1086/704010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Chesapeake Bay is the primary nursery for striped bass (Morone saxatilis), which are increasingly being exposed to hypoxic waters. Tolerance to hypoxia in fish is generally determined by a single exposure of an isolated individual or by exposing large groups of conspecifics to hypoxia without regard to social status. The importance of social context in determining physiological responses to stressors is being increasingly recognized. To determine whether social interactions influence hypoxia tolerance (HT) in striped bass, loss of equilibrium HT was assessed in the same fish while manipulating the social environment around it. Small group settings were used to be more representative of the normal sociality experienced by this species than the paired encounters typically used. After establishing the dominance hierarchy within a group of fish, HT was determined collectively for the individuals in that group, and then new groups were constructed from the same pool of fish. Individuals could then be followed across multiple settings for both repeatability of HT and hierarchy position ( X ¯ = 4.2 ± 0.91 SD groups per individual). HT increased with repeated exposures to hypoxia ( P < 0.001 ), with a significant increase by a third exposure ( P = 0.004 ). Despite this changing HT, rank order of HT was significantly repeatable across trials for 6 mo ( P = 0.012 ). Social status was significantly repeatable across trials of different group composition ( P = 0.02 ) and unrelated to growth rate but affected HT weakly in a complex interaction with size. Final HT was significantly correlated with blood [hemoglobin] and hematocrit. The repeatability and large intraspecific variance of HT in juvenile striped bass suggest that HT is potentially an important determinant of Darwinian fitness in an increasingly hypoxic Chesapeake Bay.
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Burggren WW, Mendez-Sanchez JF, Martínez Bautista G, Peña E, Martínez García R, Alvarez González CA. Developmental changes in oxygen consumption and hypoxia tolerance in the heat and hypoxia-adapted tabasco line of the Nile tilapia Oreochromis niloticus, with a survey of the metabolic literature for the genus Oreochromis. JOURNAL OF FISH BIOLOGY 2019; 94:732-744. [PMID: 30847924 DOI: 10.1111/jfb.13945] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Accepted: 03/01/2019] [Indexed: 06/09/2023]
Abstract
The genus Oreochromis is among the most popular of the tilapiine cichlid tribe for aquaculture. However, their temperature and hypoxia tolerance, if tested at all, is usually tested at temperatures of 20-25°C, rather than at the considerably higher temperatures of 30-35°C typical of tropical aquaculture. We hypothesized that both larvae and adults of the heat and hypoxia-adapted Tabasco-line of the Nile tilapia Oreochromis niloticus would be relatively hypoxia-tolerant. Oxygen consumption rate ( M ˙ O 2 ), Q10 and aquatic surface respiration (ASR) was measured using closed respirometry at 2 (c. 0.2 g), 30 (c. 2-5 g), 105 c. (10-15 g) and 240 (c. 250 g) days of development, at 25°C, 30°C and 35°C. M ˙ O 2 at 30°C was inversely related to body mass: c. 90 μM O2 g-1 /h in larvae down to c. 1 μM O2 g-1 /h in young adults. Q10 for M ˙ O 2 was typical for fish over the range 25-35°C of 1.5-2.0. ASR was exhibited by 50% of the fish at pO2 of 15-50 mmHg in a temperature-dependent fashion. However, the largest adults showed notable ASR only when pO2 fell to below 10 mmHg. Remarkably, pcrit for M ˙ O 2 was 12-17 mmHg at 25-30°C and still only 20-25 mmHg across development at 35°C. These values are among the lowest measured for teleost fishes. Noteworthy is that all fish maintain equilibrium, ventilated their gills and showed routine locomotor action for 10-20 min after M ˙ O 2 ceased at near anoxia and when then returned to oxygenated waters, all fish survived, further indicating a remarkable hypoxic tolerance. Remarkably, data assembled for M ˙ O 2 from >30 studies showed a > x2000 difference, which we attribute to calculation or conversion errors. Nonetheless, pcrit was very low for all Oreochromis sp. and lowest in the heat and hypoxia-adapted Tabasco line.
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Affiliation(s)
- Warren W Burggren
- Developmental Integrative Biology Group, Department of Biology, University of North Texas, Denton, Texas, USA
| | - Jose F Mendez-Sanchez
- Laboratorio de Ecofisiología Animal, Facultad de Ciencias, Universidad Autónoma del Estado de México, Toluca, Mexico
| | - Gil Martínez Bautista
- Laboratorio de Acuicultura Tropical, División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Mexico
| | - Emyr Peña
- Laboratorio de Acuicultura Tropical, División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Mexico
| | - Rafael Martínez García
- Laboratorio de Acuicultura Tropical, División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Mexico
| | - Carlos A Alvarez González
- Laboratorio de Acuicultura Tropical, División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Mexico
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13
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Intertidal triplefin fishes have a lower critical oxygen tension (Pcrit), higher maximal aerobic capacity, and higher tissue glycogen stores than their subtidal counterparts. J Comp Physiol B 2019; 189:399-411. [DOI: 10.1007/s00360-019-01216-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 03/16/2019] [Accepted: 03/20/2019] [Indexed: 01/12/2023]
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14
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Svendsen MBS, Johansen JL, Bushnell PG, Skov PV, Norin T, Domenici P, Steffensen JF, Abe A. Are all bony fishes oxygen regulators? Evidence for oxygen regulation in a putative oxygen conformer, the swamp eel Synbranchus marmoratus. JOURNAL OF FISH BIOLOGY 2019; 94:178-182. [PMID: 30421417 DOI: 10.1111/jfb.13861] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 10/30/2018] [Indexed: 06/09/2023]
Abstract
This study investigated the oxygen consumption of the putative oxygen conformer marbled swamp eel Synbranchus marmoratus during progressive hypoxia. Earlier studies have not reached an agreement on whether S. marmoratus is a conformer or a regulator. Our results support the view that S. marmoratus is an oxygen regulator, like most bony fishes.
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Affiliation(s)
| | - Jacob L Johansen
- Marine Biology Laboratory, New York University -Abu Dhabi, Abu Dhabi, UAE
| | - Peter G Bushnell
- Department of Biological Sciences, Indiana University South Bend, South Bend, Indiana, USA
| | - Peter V Skov
- Technical University of Denmark, DTU Aqua, Section for Aquaculture, The North Sea Research Centre, Hirtshals, Denmark
| | - Tommy Norin
- Technical University of Denmark, DTU Aqua: National Institute of Aquatic Resources, Kongens Lyngby, Denmark
| | - Paolo Domenici
- IAS-CNR Istututo per lo studio degli impatti Antropici e Sostenibilità in ambiente marino
| | - John F Steffensen
- Marine Biological Section, Department of Biology, University of Copenhagen, Elsinore, Denmark
| | - Augusto Abe
- Department of Zoology, São Paulo State University, São Paulo Unesp, Biosciences Institute, Rio Claro, Brazil
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15
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Wood CM. The fallacy of the P crit - are there more useful alternatives? ACTA ACUST UNITED AC 2018; 221:221/22/jeb163717. [PMID: 30420494 DOI: 10.1242/jeb.163717] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
P crit - generally defined as the P O2 below which the animal can no longer maintain a stable rate of O2 consumption (Ṁ O2 ), such that Ṁ O2 becomes dependent upon P O2 - provides a single number into which a vast amount of experimental effort has been invested. Here, with specific reference to water-breathers, I argue that this focus on the P crit is not useful for six reasons: (1) calculation of P crit usually involves selective data editing; (2) the value of P crit depends greatly on the way it is determined; (3) there is no good theoretical justification for the concept; (4) P crit is not the transition point from aerobic to anaerobic metabolism, and it disguises what is really going on; (5) P crit is not a reliable index of hypoxia tolerance; and (6) P crit carries minimal information content. Preferable alternatives are loss of equilibrium (LOE) tests for hypoxia tolerance, and experimental description of full Ṁ O2 versus P O2 profiles accompanied by measurements of ventilation, lactate appearance and metabolic rate by calorimetry. If the goal is to assess the ability of the animal to regulate Ṁ O2 from this profile in a mathematical fashion, promising, more informative alternatives to P crit are the regulation index and Michaelis-Menten or sigmoidal allosteric analyses.
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Affiliation(s)
- Chris M Wood
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada V6T 1Z4 .,Department of Biology, McMaster University, Hamilton, ON, Canada L8S 4K1.,Rosenstiel School of Marine and Atmospheric Science, University of Miami, FL 33149, USA
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16
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Herbert NA, Bröhl S, Springer K, Kunzmann A. Clownfish in hypoxic anemones replenish host O 2 at only localised scales. Sci Rep 2017; 7:6547. [PMID: 28747629 PMCID: PMC5529556 DOI: 10.1038/s41598-017-06695-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 06/16/2017] [Indexed: 11/28/2022] Open
Abstract
The clownfish-anemone association exemplifies a symbiosis where both members benefit from nutrient exchange and protection from predators. Clownfish also perform aeration-like behaviour in their host anemones at night, but it is not yet known whether this is stimulated by the onset of hypoxia, and whether both members benefit from O2 replenishment. Oxygen at 3 distances above the sea anemone Entacmaea quadricolor (0.2, 1.2 and 2.2 cm) therefore was measured under 3 light levels (photon flux density = 0, 55 and 110 µmol m−2 s−1), with and without the anemonefish Amphiprion frenatus. Hypoxia (O2 < 50% air saturation) was recorded in the anemone, but only at 0.2 cm away from the anemone surface under dark conditions when A. frenatus was absent. This localised layer of hypoxia was eliminated by the presence of A. frenatus exhibiting aeration-like behaviour. Respirometry revealed that A. frenatus is extremely hypoxia tolerant (Scrit = 14.3% at 25 °C), suggesting that aeration behaviour does not provide a major metabolic advantage to clownfish because they do not breathe water at 0.2 cm and are not metabolically constrained by O2 at distances ≥ 1.2 cm. That the aeration behaviour of A. frenatus facilitates only the metabolism of its O2-conforming host reveals a unique aspect of this symbiotic relationship.
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Affiliation(s)
- N A Herbert
- Leigh Marine Laboratory, Institute of Marine Science, University of Auckland, PO Box 349, Warkworth, 0941, New Zealand.
| | - S Bröhl
- Leibniz Center for Tropical Marine Research (ZMT), Fahrenheitstraße 6, 28359, Bremen, Germany
| | - K Springer
- Marine Botany BreMarE, University of Bremen, Leobenerstr.1, 28359, Bremen, Germany
| | - A Kunzmann
- Leibniz Center for Tropical Marine Research (ZMT), Fahrenheitstraße 6, 28359, Bremen, Germany
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17
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Regan MD, Richards JG. Rates of hypoxia induction alter mechanisms of O 2 uptake and the critical O 2 tension of goldfish. ACTA ACUST UNITED AC 2017; 220:2536-2544. [PMID: 28476894 DOI: 10.1242/jeb.154948] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 05/02/2017] [Indexed: 12/23/2022]
Abstract
The rate of hypoxia induction (RHI) is an important but overlooked dimension of environmental hypoxia that may affect an organism's survival. We hypothesized that, compared with rapid RHI, gradual RHI will afford an organism more time to alter plastic phenotypes associated with O2 uptake and subsequently reduce the critical O2 tension (Pcrit) of the rate of O2 uptake (ṀO2 ). We investigated this by determining Pcrit values for goldfish exposed to short (∼24 min), typical (∼84 min) and long (∼480 min) duration Pcrit trials to represent different RHIs. Consistent with our predictions, long duration Pcrit trials yielded significantly lower Pcrit values (1.0-1.4 kPa) than short and typical duration trials, which did not differ (2.6±0.3 and 2.5±0.2 kPa, respectively). Parallel experiments revealed these time-related shifts in Pcrit were associated with changes to aspects of the O2 transport cascade that took place over the hypoxia exposures: gill surface areas and haemoglobin-O2 binding affinities were significantly higher in fish exposed to gradual RHIs over 480 min than fish exposed to rapid RHIs over 60 min. Our results also revealed that the choice of respirometric technique (i.e. closed versus intermittent) does not affect Pcrit or routine ṀO2 , despite the significantly reduced water pH and elevated CO2 and ammonia levels measured following closed-circuit Pcrit trials of ∼90 min. Together, our results demonstrate that gradual RHIs result in alterations to physiological parameters that enhance O2 uptake in hypoxic environments. An organism's innate Pcrit is therefore most accurately determined using rapid RHIs (<90 min) so as to avoid the confounding effects of hypoxic acclimation.
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Affiliation(s)
- Matthew D Regan
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia, Canada V6T 1Z4
| | - Jeffrey G Richards
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia, Canada V6T 1Z4
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18
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Pan YK, Ern R, Esbaugh AJ. Hypoxia tolerance decreases with body size in red drum Sciaenops ocellatus. JOURNAL OF FISH BIOLOGY 2016; 89:1488-1493. [PMID: 27328965 DOI: 10.1111/jfb.13035] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 04/18/2016] [Indexed: 06/06/2023]
Abstract
Mass-specific oxygen consumption rate, i.e. standard metabolic rate (Rs ) and critical oxygen tension (Pcrit ) of red drum Sciaenops ocellatus were measured and scaled over a 2500-fold range in mass (MF ; 0·26-686 g). Rs conformed to well established models (Rs = 3·73·91 MF (-0·21) ; r(2) = 0·86) while Pcrit increased over the size range (Pcrit = 3·15 log10 MF + 16·19; r(2) = 0·44). This relationship may be ecologically advantageous as it would allow smaller S. ocellatus to better utilize hypoxic zones as habitat and refuge from predators.
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Affiliation(s)
- Y K Pan
- University of Texas Marine Science Institute, 750 Channel View Dr, Port Aransas, TX, 78373, U.S.A
| | - R Ern
- University of Texas Marine Science Institute, 750 Channel View Dr, Port Aransas, TX, 78373, U.S.A
| | - A J Esbaugh
- University of Texas Marine Science Institute, 750 Channel View Dr, Port Aransas, TX, 78373, U.S.A
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19
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Rogers NJ, Urbina MA, Reardon EE, McKenzie DJ, Wilson RW. A new analysis of hypoxia tolerance in fishes using a database of critical oxygen level (P crit). CONSERVATION PHYSIOLOGY 2016; 4:cow012. [PMID: 27293760 PMCID: PMC4849809 DOI: 10.1093/conphys/cow012] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 03/17/2016] [Accepted: 03/19/2016] [Indexed: 05/19/2023]
Abstract
Hypoxia is a common occurrence in aquatic habitats, and it is becoming an increasingly frequent and widespread environmental perturbation, primarily as the result of anthropogenic nutrient enrichment and climate change. An in-depth understanding of the hypoxia tolerance of fishes, and how this varies among individuals and species, is required to make accurate predictions of future ecological impacts and to provide better information for conservation and fisheries management. The critical oxygen level (P crit) has been widely used as a quantifiable trait of hypoxia tolerance. It is defined as the oxygen level below which the animal can no longer maintain a stable rate of oxygen uptake (oxyregulate) and uptake becomes dependent on ambient oxygen availability (the animal transitions to oxyconforming). A comprehensive database of P crit values, comprising 331 measurements from 96 published studies, covering 151 fish species from 58 families, provides the most extensive and up-to-date analysis of hypoxia tolerance in teleosts. Methodologies for determining P crit are critically examined to evaluate its usefulness as an indicator of hypoxia tolerance in fishes. Various abiotic and biotic factors that interact with hypoxia are analysed for their effect on P crit, including temperature, CO2, acidification, toxic metals and feeding. Salinity, temperature, body mass and routine metabolic rate were strongly correlated with P crit; 20% of variation in the P crit data set was explained by these four variables. An important methodological issue not previously considered is the inconsistent increase in partial pressure of CO2 within a closed respirometer during the measurement of P crit. Modelling suggests that the final partial pressure of CO2 reached can vary from 650 to 3500 µatm depending on the ambient pH and salinity, with potentially major effects on blood acid-base balance and P crit itself. This database will form part of a widely accessible repository of physiological trait data that will serve as a resource to facilitate future studies of fish ecology, conservation and management.
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Affiliation(s)
- Nicholas J Rogers
- Biosciences, College of Life and Environmental Sciences, Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Mauricio A Urbina
- Biosciences, College of Life and Environmental Sciences, Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Erin E Reardon
- Biosciences, College of Life and Environmental Sciences, Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - David J McKenzie
- Centre for Marine Biodiversity Exploitation and Conservation (Marbec), UMR 9190 CNRS-Université Montpellier-Ifremer-IRD, Université Montpellier, Place Eugène Bataillon, Montpellier cedex 5 34095, France
| | - Rod W Wilson
- Biosciences, College of Life and Environmental Sciences, Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
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20
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Chabot D, McKenzie DJ, Craig JF. Metabolic rate in fishes: definitions, methods and significance for conservation physiology. JOURNAL OF FISH BIOLOGY 2016; 88:1-9. [PMID: 26768969 DOI: 10.1111/jfb.12873] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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21
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Regan MD, Gill I, Richards JG. Calorespirometry reveals that goldfish prioritize aerobic metabolism over metabolic rate depression in all but near-anoxic environments. J Exp Biol 2016; 220:564-572. [DOI: 10.1242/jeb.145169] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 11/21/2016] [Indexed: 10/20/2022]
Abstract
Metabolic rate depression (MRD) has long been proposed as the key metabolic strategy of hypoxic survival, but surprisingly the effects of changes in hypoxic O2 tensions (PwO2) on MRD are largely unexplored. We simultaneously measured the O2 consumption rate (ṀO2) and metabolic heat of goldfish using calorespirometry to test the hypothesis that MRD is employed at hypoxic PwO2s and initiated just below Pcrit, the PwO2 below which ṀO2 is forced to progressively decline as the fish oxyconforms to decreasing PwO2. Specifically, we used closed-chamber and flow-through calorespirometry together with terminal sampling experiments to examine the effects of PwO2 and time on ṀO2, metabolic heat and anaerobic metabolism (lactate and ethanol production). The closed-chamber and flow-through experiments yielded slightly different results. Under closed-chamber conditions with a continually decreasing PwO2, goldfish showed a Pcrit of 3.0±0.3 kPa and metabolic heat production was only depressed at PwO2 between 0 and 0.67 kPa. Under flow-through conditions with PwO2 held at a variety of oxygen tensions for 1 and 4 h, goldfish also initiated MRD between 0 and 0.67 kPa but maintained ṀO2 to 0.67 kPa, indicating that Pcrit is at or below this PwO2. Anaerobic metabolism was strongly activated at PwO2 ≤1.3 kPa, but only used within the first hour at 1.3 and 0.67 kPa as anaerobic end-products did not accumulate between 1 and 4 h exposure. Taken together, it appears that goldfish reserve MRD for near-anoxia, supporting routine metabolic rate at sub-Pcrit PwO2s with the help of anaerobic glycolysis in the closed-chamber experiments, and aerobically after an initial (<1 h) activation of anaerobic metabolism in the flow-through experiments, even at 0.67 kPa PwO2.
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Affiliation(s)
- Matthew D. Regan
- Department of Zoology, University of British Columbia, 6270 University Blvd., Vancouver, BC V6T 1Z4, Canada
| | - Ivan Gill
- Department of Zoology, University of British Columbia, 6270 University Blvd., Vancouver, BC V6T 1Z4, Canada
| | - Jeffrey G. Richards
- Department of Zoology, University of British Columbia, 6270 University Blvd., Vancouver, BC V6T 1Z4, Canada
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