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Moretto WI, Stahl AK, Mehta RS. Effects of acute temperature change on California moray prey manipulation and transport behavior. ZOOLOGY 2022; 154:126030. [PMID: 35905540 DOI: 10.1016/j.zool.2022.126030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/08/2022] [Accepted: 07/09/2022] [Indexed: 12/01/2022]
Abstract
California moray eels, Gymnothorax mordax, are benthic predatory residents of southern California kelp forest ecosystems. California morays around Catalina Island move vertically through the water column to feed, exposing them to a wide range of temperatures. For a predatory fish, morays have a relatively large prey handling repertoire that enable them to manipulate their prey before swallowing. Prey manipulation behaviors include shaking, spinning, knotting, and ramming prey against other objects. Morays also have observable transport mechanics where they protract and retract their pharyngeal jaws to swallow prey. We examined prey manipulation and transport behaviors at four temperature treatments that simulated the range of environmental temperatures morays encounter in the wild. We hypothesized that higher temperatures will increase the prevalence, duration, and rate of whole body prey manipulation behaviors and decrease the duration of prey transport time. Previous temperature studies focused on fishes occupying intermediate trophic levels. Therefore, understanding how acute temperature affects feeding behavior of the California moray eel, an abundant predatory fish, is especially important, as changes in environmental temperature may have disproportionate effects in their marine community. Five morays were acutely exposed to 15, 18, 21, 24 °C temperatures and their subsequent feeding behaviors were filmed and quantified. Individuals were offered the same relative prey mass (15 %) in relation to their body mass throughout the study. We compared the number of times each prey manipulation behavior occurred, the mean time morays employed each behavior, and the rate (number of times per second) each behavior was performed across different temperatures. Our data demonstrates that absolute time spent knotting varies significantly across temperature. Knotting, often used to remove pieces from larger prey, was most frequent at 21 and 24 °C. The average duration of knotting also increased with temperature. The rates of prey manipulation behaviors did not vary significantly with temperature. Finally, transport behavior did not vary across treatments. Our study shows that knotting behavior in the California moray is responsive to environmental temperatures and that morays may be able to manipulate larger prey in warmer waters. These behavioral data may have important implications for predator-prey relationships under dynamic and future ocean conditions.
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Affiliation(s)
- Wave I Moretto
- Department of Ecology and Evolutionary Biology, Long Marine Laboratory, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Allegra K Stahl
- Department of Ecology and Evolutionary Biology, Long Marine Laboratory, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Rita S Mehta
- Department of Ecology and Evolutionary Biology, Long Marine Laboratory, University of California Santa Cruz, Santa Cruz, CA 95060, USA.
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Mignucci A, Bourjea J, Forget F, Allal H, Dutto G, Gasset E, McKenzie DJ. Cardiac and behavioural responses to hypoxia and warming in free-swimming gilthead seabream, Sparus aurata. J Exp Biol 2021; 224:271040. [PMID: 34308993 DOI: 10.1242/jeb.242397] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 06/16/2021] [Indexed: 11/20/2022]
Abstract
Gilthead seabream were equipped with intraperitoneal biologging tags to investigate cardiac responses to hypoxia and warming, comparing when fish were either swimming freely in a tank with conspecifics or confined to individual respirometers. After tag implantation under anaesthesia, heart rate (fH) required 60 h to recover to a stable value in a holding tank. Subsequently, when undisturbed under control conditions (normoxia, 21°C), mean fH was always significantly lower in the tank than in the respirometers. In progressive hypoxia (100% to 15% oxygen saturation), mean fH in the tank was significantly lower than in the respirometers at oxygen levels down to 40%, with significant bradycardia in both holding conditions below this level. Simultaneous logging of tri-axial body acceleration revealed that spontaneous activity, inferred as the variance of external acceleration (VARm), was low and invariant in hypoxia. Warming (21 to 31°C) caused progressive tachycardia with no differences in fH between holding conditions. Mean VARm was, however, significantly higher in the tank during warming, with a positive relationship between VARm and fH across all temperatures. Therefore, spontaneous activity contributed to raising fH of fish in the tank during warming. Mean fH in respirometers had a highly significant linear relationship with mean rates of oxygen uptake, considering data from hypoxia and warming together. The high fH of confined seabream indicates that respirometry techniques may bias estimates of metabolic traits in some fishes, and that biologging on free-swimming fish will provide more reliable insight into cardiac and behavioural responses to environmental stressors by fish in their natural environment.
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Affiliation(s)
- Alexandre Mignucci
- MARBEC, Université de Montpelier, CNRS, IRD, Ifremer, 34200 Sète, France
| | - Jérôme Bourjea
- MARBEC, Université de Montpelier, CNRS, IRD, Ifremer, 34200 Sète, France
| | - Fabien Forget
- MARBEC, Université de Montpelier, CNRS, IRD, Ifremer, 34200 Sète, France
| | - Hossein Allal
- CHU de Montpellier, Service Chirurgie Pédiatrique, 34000 Montpellier, France
| | - Gilbert Dutto
- MARBEC, Université de Montpellier, CNRS, IRD, Ifremer, 34250, Palavas-les-Flots, France
| | - Eric Gasset
- MARBEC, Université de Montpellier, CNRS, IRD, Ifremer, 34250, Palavas-les-Flots, France
| | - David J McKenzie
- MARBEC, Université de Montpellier, CNRS, IRD, Ifremer, 34095 Montpellier, France
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3
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Wild Zebrafish Sentinels: Biological Monitoring of Site Differences Using Behavior and Morphology. TOXICS 2021; 9:toxics9070165. [PMID: 34357908 PMCID: PMC8309768 DOI: 10.3390/toxics9070165] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/03/2021] [Accepted: 07/09/2021] [Indexed: 12/19/2022]
Abstract
Environmental change poses a devastating risk to human and environmental health. Rapid assessment of water conditions is necessary for monitoring, evaluating, and addressing this global health danger. Sentinels or biological monitors can be deployed in the field using minimal resources to detect water quality changes in real time, quickly and cheaply. Zebrafish (Danio rerio) are ideal sentinels for detecting environmental changes due to their biomedical tool kit, widespread geographic distribution, and well-characterized phenotypic responses to environmental disturbances. Here, we demonstrate the utility of zebrafish sentinels by characterizing phenotypic differences in wild zebrafish between two field sites in India. Site 1 was a rural environment with flowing water, low-hypoxic conditions, minimal human-made debris, and high iron and lead concentrations. Site 2 was an urban environment with still water, hypoxic conditions, plastic pollution, and high arsenic, iron, and chromium concentrations. We found that zebrafish from Site 2 were smaller, more cohesive, and less active than Site 1 fish. We also found sexually dimorphic body shapes within the Site 2, but not the Site 1, population. Advancing zebrafish sentinel research and development will enable rapid detection, evaluation, and response to emerging global health threats.
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Mucha S, Chapman LJ, Krahe R. The weakly electric fish, Apteronotus albifrons, actively avoids experimentally induced hypoxia. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2021; 207:369-379. [PMID: 33751182 PMCID: PMC8079295 DOI: 10.1007/s00359-021-01470-w] [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: 07/01/2020] [Revised: 02/16/2021] [Accepted: 02/18/2021] [Indexed: 11/15/2022]
Abstract
Anthropogenic environmental degradation has led to an increase in the frequency and prevalence of aquatic hypoxia (low dissolved oxygen concentration, DO), which may affect habitat quality for water-breathing fishes. The weakly electric black ghost knifefish, Apteronotus albifrons, is typically found in well-oxygenated freshwater habitats in South America. Using a shuttle-box design, we exposed juvenile A. albifrons to a stepwise decline in DO from normoxia (> 95% air saturation) to extreme hypoxia (10% air saturation) in one compartment and chronic normoxia in the other. On average, A. albifrons actively avoided the hypoxic compartment below 22% air saturation. Hypoxia avoidance was correlated with upregulated swimming activity. Following avoidance, fish regularly ventured back briefly into deep hypoxia. Hypoxia did not affect the frequency of their electric organ discharges. Our results show that A. albifrons is able to sense hypoxia at non-lethal levels and uses active avoidance to mitigate its adverse effects.
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Affiliation(s)
- Stefan Mucha
- Institute of Biology, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099, Berlin, Germany.
| | - Lauren J Chapman
- Department of Biology, McGill University, Montreal, QC, H3A 1B1, Canada
| | - Rüdiger Krahe
- Institute of Biology, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099, Berlin, Germany.,Department of Biology, McGill University, Montreal, QC, H3A 1B1, Canada
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Martos-Sitcha JA, Sosa J, Ramos-Valido D, Bravo FJ, Carmona-Duarte C, Gomes HL, Calduch-Giner JÀ, Cabruja E, Vega A, Ferrer MÁ, Lozano M, Montiel-Nelson JA, Afonso JM, Pérez-Sánchez J. Ultra-Low Power Sensor Devices for Monitoring Physical Activity and Respiratory Frequency in Farmed Fish. Front Physiol 2019; 10:667. [PMID: 31191358 PMCID: PMC6548888 DOI: 10.3389/fphys.2019.00667] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 05/09/2019] [Indexed: 01/31/2023] Open
Abstract
Integration of technological solutions aims to improve accuracy, precision and repeatability in farming operations, and biosensor devices are increasingly used for understanding basic biology during livestock production. The aim of this study was to design and validate a miniaturized tri-axial accelerometer for non-invasive monitoring of farmed fish with re-programmable schedule protocols. The current device (AE-FishBIT v.1s) is a small (14 mm × 7 mm × 7 mm), stand-alone system with a total mass of 600 mg, which allows monitoring animals from 30 to 35 g onwards. The device was attached to the operculum of gilthead sea bream (Sparus aurata) and European sea bass (Dicentrarchus labrax) juveniles for monitoring their physical activity by measurements of movement accelerations in x- and y-axes, while records of operculum beats (z-axis) served as a measurement of respiratory frequency. Data post-processing of exercised fish in swimming test chambers revealed an exponential increase of fish accelerations with the increase of fish speed from 1 body-length to 4 body-lengths per second, while a close relationship between oxygen consumption (MO2) and opercular frequency was consistently found. Preliminary tests in free-swimming fish kept in rearing tanks also showed that device data recording was able to detect changes in daily fish activity. The usefulness of low computational load for data pre-processing with on-board algorithms was verified from low to submaximal exercise, increasing this procedure the autonomy of the system up to 6 h of data recording with different programmable schedules. Visual observations regarding tissue damage, feeding behavior and circulating levels of stress markers (cortisol, glucose, and lactate) did not reveal at short term a negative impact of device tagging. Reduced plasma levels of triglycerides revealed a transient inhibition of feed intake in small fish (sea bream 50-90 g, sea bass 100-200 g), but this disturbance was not detected in larger fish. All this considered together is the proof of concept that miniaturized devices are suitable for non-invasive and reliable metabolic phenotyping of farmed fish to improve their overall performance and welfare. Further work is underway for improving the attachment procedure and the full device packaging.
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Affiliation(s)
- Juan Antonio Martos-Sitcha
- Nutrigenomics and Fish Growth Endocrinology Group, Institute of Aquaculture Torre de la Sal, Consejo Superior de Investigaciones Científicas (CSIC), Castellón, Spain.,Department of Biology, Faculty of Marine and Environmental Sciences, Instituto Universitario de Investigación Marina (INMAR), Campus de Excelencia Internacional del Mar (CEI-MAR), University of Cádiz, Cádiz, Spain
| | - Javier Sosa
- Institute for Applied Microelectronics (IUMA), University of Las Palmas de Gran Canaria, Las Palmas, Spain
| | - Dailos Ramos-Valido
- Institute for Applied Microelectronics (IUMA), University of Las Palmas de Gran Canaria, Las Palmas, Spain
| | - Francisco Javier Bravo
- Institute of Microelectronics of Barcelona (IMB-CNM), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain
| | - Cristina Carmona-Duarte
- Technological Centre for Innovation in Communications (iDeTIC), University of Las Palmas de Gran Canaria, Las Palmas, Spain
| | | | - Josep Àlvar Calduch-Giner
- Nutrigenomics and Fish Growth Endocrinology Group, Institute of Aquaculture Torre de la Sal, Consejo Superior de Investigaciones Científicas (CSIC), Castellón, Spain
| | - Enric Cabruja
- Institute of Microelectronics of Barcelona (IMB-CNM), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain
| | - Aurelio Vega
- Institute for Applied Microelectronics (IUMA), University of Las Palmas de Gran Canaria, Las Palmas, Spain
| | - Miguel Ángel Ferrer
- Technological Centre for Innovation in Communications (iDeTIC), University of Las Palmas de Gran Canaria, Las Palmas, Spain
| | - Manuel Lozano
- Institute of Microelectronics of Barcelona (IMB-CNM), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain
| | | | - Juan Manuel Afonso
- Aquaculture Research Group, Institute of Sustainable Aquaculture and Marine Ecosystems (IU-ECOAQUA), University of Las Palmas de Gran Canaria, Las Palmas, Spain
| | - Jaume Pérez-Sánchez
- Nutrigenomics and Fish Growth Endocrinology Group, Institute of Aquaculture Torre de la Sal, Consejo Superior de Investigaciones Científicas (CSIC), Castellón, Spain
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Sutton AO, Turko AJ, McLaughlin RL, Wright PA. Behavioral and Physiological Responses of an Amphibious, Euryhaline Mangrove Fish to Acute Salinity Exposure. COPEIA 2018. [DOI: 10.1643/cp-17-665] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Domenici P, Steffensen JF, Marras S. The effect of hypoxia on fish schooling. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0236. [PMID: 28673914 DOI: 10.1098/rstb.2016.0236] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2016] [Indexed: 11/12/2022] Open
Abstract
Low-oxygen areas are expanding in the oceans as a result of climate change. Work carried out during the past two decades suggests that, in addition to impairing basic physiological functions, hypoxia can also affect fish behaviour. Given that many fish species are known to school, and that schooling is advantageous for their survival, the effect of hypoxia on schooling behaviour may have important ecological consequences. Here, we review the effects of hypoxia on school structure and dynamics, together with the mechanisms that cause an increase in school volume and that ultimately lead to school disruption. Furthermore, the effect of hypoxia generates a number of trade-offs in terms of schooling positions and school structure. Field observations have found that large schools of fish can exacerbate hypoxic conditions, with potential consequences for school structure and size. Therefore, previous models that predict the maximum size attainable by fish schools in relation to oxygen levels are also reviewed. Finally, we suggest that studies on the effect of hypoxia on schooling need to be integrated with those on temperature and ocean acidifications within a framework aimed at increasing our ability to predict the effect of multiple stressors of climate change on fish behaviour.This article is part of the themed issue 'Physiological determinants of social behaviour in animals'.
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Affiliation(s)
- Paolo Domenici
- IAMC-CNR, Institute for the Coastal Marine Environment, National Research Council, Torregrande 09170, Oristano, Italy
| | - John F Steffensen
- Marine Biological Section, University of Copenhagen, Københavns Universitet, Strandpromenaden 5, DK-3000 Helsingør, Denmark
| | - Stefano Marras
- IAMC-CNR, Institute for the Coastal Marine Environment, National Research Council, Torregrande 09170, Oristano, Italy
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Townhill BL, Pinnegar JK, Righton DA, Metcalfe JD. Fisheries, low oxygen and climate change: how much do we really know? JOURNAL OF FISH BIOLOGY 2017; 90:723-750. [PMID: 27861866 DOI: 10.1111/jfb.13203] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 10/11/2016] [Indexed: 06/06/2023]
Abstract
As a result of long-term climate change, regions of the ocean with low oxygen concentrations are predicted to occur more frequently and persist for longer periods of time in the future. When low levels of oxygen are present, this places additional pressure on marine organisms to meet their metabolic requirements, with implications for growth, feeding and reproduction. Extensive research has been carried out on the effects of acute hypoxia, but far less on long-term chronic effects of low oxygen zones, especially with regard to commercially important fishes and shellfishes. To provide further understanding on how commercial species could be affected, the results of relevant experiments must support population and ecosystem models. This is not easy because individual effects are wide-ranging; for example, studies to date have shown that low oxygen zones can affect predator-prey relationships as some species are able to tolerate low oxygen more than others. Some fishes may move away from areas until oxygen levels return to acceptable levels, while others take advantage of a reduced start response in prey fishes and remain in the area to feed. Sessile or less mobile species such as shellfishes are unable to move out of depleted oxygen zones. Some species can tolerate low oxygen levels for only short periods of time, while others are able to acclimatize. To advance the knowledge-base further, a number of promising technological and modelling-based developments and the role of physiological data within these, are proposed. These include advances in remote telemetry (tagging) and sensor technologies, trait-based analyses to provide insight into how whole assemblages might respond in the future, research into long-term adaptability of species, population and ecosystem modelling techniques and quantification of economic effects. In addition, more detailed oxygen monitoring and projections are required to better understand the likely temporal and local-scale changes in oxygen.
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Affiliation(s)
- B L Townhill
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Pakefield Road, Lowestoft, Suffolk, NR33 0HT, U.K
| | - J K Pinnegar
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Pakefield Road, Lowestoft, Suffolk, NR33 0HT, U.K
- School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, U.K
| | - D A Righton
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Pakefield Road, Lowestoft, Suffolk, NR33 0HT, U.K
| | - J D Metcalfe
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Pakefield Road, Lowestoft, Suffolk, NR33 0HT, U.K
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9
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Marshall WS, Tait JC, Mercer EW. Salinity Preference in the Estuarine Teleost Fish Mummichog (Fundulus heteroclitus): Halocline Behavior. Physiol Biochem Zool 2016; 89:225-32. [DOI: 10.1086/686037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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10
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Badr A, El-Sayed MF, Vornanen M. Effects of seasonal acclimatization on temperature dependence of cardiac excitability in the roach, Rutilus rutilus. ACTA ACUST UNITED AC 2016; 219:1495-504. [PMID: 26994185 DOI: 10.1242/jeb.138347] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 03/03/2016] [Indexed: 01/06/2023]
Abstract
Temperature sensitivity of electrical excitability is a potential limiting factor for performance level and thermal tolerance of excitable tissues in ectothermic animals. To test whether the rate and rhythm of the heart acclimatize to seasonal temperature changes, thermal sensitivity of cardiac excitation in a eurythermal teleost, the roach (Rutilus rutilus), was examined. Excitability of the heart was determined from in vivo electrocardiograms and in vitro microelectrode recordings of action potentials (APs) from winter and summer roach acclimatized to 4 and 18°C, respectively. Under heat ramps (3°C h(-1)), starting from the acclimatization temperatures of the fish, heart rate increased to maximum values of 78±5 beats min(-1) (at 19.8±0.5°C) and 150±7 beats min(-1) (at 28.1±0.5°C) for winter and summer roach, respectively, and then declined in both groups. Below 20°C, heart rate was significantly higher in winter than in summer roach (P<0.05), indicating positive thermal compensation. Cardiac arrhythmias appeared with rising temperature as missing QRS complexes, increase in variability of heart rate, episodes of atrial tachycardia, ventricular bradycardia and complete cessation of the heartbeat (asystole) in both winter and summer roach. Unlike winter roach, atrial APs of summer roach had a distinct early repolarization phase, which appeared as shorter durations of atrial AP at 10% and 20% repolarization levels in comparison to winter roach (P<0.05). In contrast, seasonal acclimatization had only subtle effects on ventricular AP characteristics. Plasticity of cardiac excitation appears to be necessary for seasonal improvements in performance level and thermal resilience of the roach heart.
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Affiliation(s)
- A Badr
- Department of Environmental and Biological Sciences, Faculty of Science and Forestry, University of Eastern Finland, 80101 Joensuu, Finland Department of Zoology, Faculty of Science, Sohag University, 82524 Sohag, Egypt
| | - M F El-Sayed
- Department of Zoology, Faculty of Science, Sohag University, 82524 Sohag, Egypt
| | - M Vornanen
- Department of Environmental and Biological Sciences, Faculty of Science and Forestry, University of Eastern Finland, 80101 Joensuu, Finland
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Sopinka NM, Donaldson MR, O’Connor CM, Suski CD, Cooke SJ. Stress Indicators in Fish. FISH PHYSIOLOGY 2016. [DOI: 10.1016/b978-0-12-802728-8.00011-4] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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12
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Metcalfe JD, Wright S, Tudorache C, Wilson RP. Recent advances in telemetry for estimating the energy metabolism of wild fishes. JOURNAL OF FISH BIOLOGY 2016; 88:284-97. [PMID: 26592370 DOI: 10.1111/jfb.12804] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 08/20/2015] [Indexed: 05/26/2023]
Abstract
Metabolic rate is a critical factor in animal biology and ecology, providing an objective measure that can be used in attributing a cost to different activities and to assessing what animals do against some optimal behaviour. Ideally, metabolic rate would be estimated directly by measuring heat output but, until recently, this has not been easily tractable with fishes so instead metabolic rate is usually estimated using indirect methods. In the laboratory, oxygen consumption rate is the indirect method most frequently used for estimating metabolic rate, but technical requirements preclude the measurement of either heat output or oxygen consumption rate in free-ranging fishes. There are other field methods for estimating metabolic rate that can be used with mammals and birds but, again, these cannot be used with fishes. Here, the use of electronic devices that record body acceleration in three dimensions (accelerometry) is considered. Accelerometry is a comparatively new telemetric method for assessing energy metabolism in animals. Correlations between dynamic body acceleration (DBA) and oxygen consumption rate demonstrate that this will be a useful proxy for estimating activity-specific energy expenditure from fishes in mesocosm or field studies over extended periods where other methods (e.g. oxygen consumption rate) are not feasible. DBA therefore has potential as a valuable tool for attributing cost to different activities. This could help in gaining a full picture of how fishes make energy-based trade-offs between different levels of activity when faced with conflicting or competing demands arising from increased and combined environmental stressors.
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Affiliation(s)
- J D Metcalfe
- Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft NR33 0HT, U.K
| | - S Wright
- Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft NR33 0HT, U.K
- College of Science, Swansea University, Singleton Park, Swansea SA2 8PP, U.K
| | - C Tudorache
- Sylvius Laboratory, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
| | - R P Wilson
- College of Science, Swansea University, Singleton Park, Swansea SA2 8PP, U.K
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Metcalfe JD, Le Quesne WJF, Cheung WWL, Righton DA. Conservation physiology for applied management of marine fish: an overview with perspectives on the role and value of telemetry. Philos Trans R Soc Lond B Biol Sci 2012; 367:1746-56. [PMID: 22566680 DOI: 10.1098/rstb.2012.0017] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Physiological studies focus on the responses of cells, tissues and individuals to stressors, usually in laboratory situations. Conservation and management, on the other hand, focus on populations. The field of conservation physiology addresses the question of how abiotic drivers of physiological responses at the level of the individual alter requirements for successful conservation and management of populations. To achieve this, impacts of physiological effects at the individual level need to be scaled to impacts on population dynamics, which requires consideration of ecology. Successfully realizing the potential of conservation physiology requires interdisciplinary studies incorporating physiology and ecology, and requires that a constructive dialogue develops between these traditionally disparate fields. To encourage this dialogue, we consider the increasingly explicit incorporation of physiology into ecological models applied to marine fish conservation and management. Conservation physiology is further challenged as the physiology of an individual revealed under laboratory conditions is unlikely to reflect realized responses to the complex variable stressors to which it is exposed in the wild. Telemetry technology offers the capability to record an animal's behaviour while simultaneously recording environmental variables to which it is exposed. We consider how the emerging insights from telemetry can strengthen the incorporation of physiology into ecology.
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Affiliation(s)
- J D Metcalfe
- Centre for Environment Fisheries and Aquaculture Science, Lowestoft Laboratory, Pakefield Road, Lowestoft, Suffolk NR33 0HT, UK.
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15
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Svendsen JC, Steffensen JF, Aarestrup K, Frisk M, Etzerodt A, Jyde M. Excess posthypoxic oxygen consumption in rainbow trout (Oncorhynchus mykiss): recovery in normoxia and hypoxia. CAN J ZOOL 2012. [DOI: 10.1139/z11-095] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Under certain conditions, a number of fish species may perform brief excursions into severe hypoxia and return to water with a higher oxygen content. The term severe hypoxia describes oxygen conditions that are below the critical oxygen saturation (Scrit), defined here as the oxygen threshold at which the standard metabolic rate becomes dependent upon the ambient oxygen content. Using rainbow trout ( Oncorhynchus mykiss (Walbaum, 1792), this study quantified the excess posthypoxic oxygen consumption (EPHOC) occurring after exposure to oxygen availability below Scrit. Tests showed that Scrit was 13.5% air saturation (O2sat). Fish were exposed to 10% O2sat for 0.97 h, and the EPHOC was quantified in normoxia (≥95% O2sat) and hypoxia (30% O2sat) to test the hypothesis that reduced oxygen availability would decrease the peak metabolic rate (MO2peak) and prolong the duration of the metabolic recovery. Results showed that MO2peak during the recovery was reduced from 253 to 127 mg O2·kg–1·h–1 in hypoxia compared with normoxia. Metabolic recovery lasted 5.2 h in normoxia and 9.8 h in hypoxia. The EPHOC, however, did not differ between the two treatments. Impeded metabolic recovery in hypoxia may have implications for fish recovering from exposure to oxygen availability below Scrit.
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Affiliation(s)
- Jon Christian Svendsen
- University of Copenhagen, Marine Biological Laboratory, Biological Institute, Strandpromenaden 5, DK-3000 Helsingør, Denmark
| | - John Fleng Steffensen
- University of Copenhagen, Marine Biological Laboratory, Biological Institute, Strandpromenaden 5, DK-3000 Helsingør, Denmark
| | - Kim Aarestrup
- Technical University of Denmark, National Institute of Aquatic Resources, Freshwater Fisheries, Vejlsøvej 39, DK-8600 Silkeborg, Denmark
| | - Michael Frisk
- University of Copenhagen, Marine Biological Laboratory, Biological Institute, Strandpromenaden 5, DK-3000 Helsingør, Denmark
| | - Anne Etzerodt
- University of Copenhagen, Marine Biological Laboratory, Biological Institute, Strandpromenaden 5, DK-3000 Helsingør, Denmark
| | - Mads Jyde
- University of Copenhagen, Marine Biological Laboratory, Biological Institute, Strandpromenaden 5, DK-3000 Helsingør, Denmark
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Cook DG, Wells RMG, Herbert NA. Anaemia adjusts the aerobic physiology of snapper (Pagrus auratus) and modulates hypoxia avoidance behaviour during oxygen choice presentations. ACTA ACUST UNITED AC 2011; 214:2927-34. [PMID: 21832136 DOI: 10.1242/jeb.057091] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The effect of altered oxygen transport potential on behavioural responses to environmental hypoxia was tested experimentally in snapper, Pagrus auratus, treated with a haemolytic agent (phenylhydrazine) or a sham protocol. Standard metabolic rate was not different between anaemic and normocythaemic snapper (Hct=6.7 and 25.7 g dl(-1), respectively), whereas maximum metabolic rate, and hence aerobic scope (AS), was consistently reduced in anaemic groups at all levels of water P(O(2)) investigated (P<0.01). This reduction of AS conferred a higher critical oxygen limit (P(crit)) to anaemic fish (8.6±0.6 kPa) compared with normocythaemic fish (5.3±0.4 kPa), thus demonstrating reduced hypoxic tolerance in anaemic groups. In behavioural choice experiments, the critical avoidance P(O(2)) in anaemic fish was 6.6±2.5 kPa compared with 2.9±0.5 kPa for controls (P<0.01). Behavioural avoidance was not associated with modulation of swimming speed. Despite differences in physiological and behavioural parameters, both groups avoided low P(O(2)) just below their P(crit), indicating that avoidance was triggered consistently when AS limits were reached and anaerobic metabolism was unavoidable. This was confirmed by high levels of plasma lactate in both treatments at the point of avoidance. This is the first experimental demonstration of avoidance behaviour being modulated by internal physiological state. From an ecological perspective, fish with disturbed oxygen delivery potential arising from anaemia, pollution or stress are likely to avoid environmental hypoxia at a higher P(O(2)) than normal fish.
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Affiliation(s)
- Denham G Cook
- Leigh Marine Laboratory, The University of Auckland, Leigh, Warkworth 0941, New Zealand
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Poulsen SB, Jensen LF, Nielsen KS, Malte H, Aarestrup K, Svendsen JC. Behaviour of rainbow trout Oncorhynchus mykiss presented with a choice of normoxia and stepwise progressive hypoxia. JOURNAL OF FISH BIOLOGY 2011; 79:969-979. [PMID: 21967584 DOI: 10.1111/j.1095-8649.2011.03069.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The objective of this study was to identify behavioural adjustments leading to avoidance of hypoxia. Using the oxygen-sensitive species rainbow trout Oncorhynchus mykiss as a model, individual fish were recorded while moving freely between two sides of a test arena: one with normoxia and one with stepwise progressive hypoxia [80-30% dissolved oxygen (DO) air saturation]. The results demonstrated a gradual decrease in the total time spent in hypoxia starting at 80% DO air saturation. At this DO level, the avoidance of hypoxia could not be attributed to changes in spontaneous swimming speed, neither in normoxia nor in hypoxia. Reducing the DO level to 60% air saturation resulted in decreased spontaneous swimming speed in normoxia, yet the number of trips to the hypoxic side of the test arena remained unchanged. Moreover, data revealed increased average residence time per trip in normoxia at DO levels ≤60% air saturation and decreased average residence time per trip in hypoxia at DO levels ≤50% air saturation. Finally, the spontaneous swimming speed in hypoxia increased at DO levels ≤40% air saturation and the number of trips to hypoxia decreased at the 30% DO air saturation level. Thus, avoidance of the deepest hypoxia was connected with a reduced number of trips to hypoxia as well as decreased and increased spontaneous swimming speed in normoxia and hypoxia, respectively. Collectively, the data support the conclusions that the mechanistic basis for avoidance of hypoxia may (1) not involve changes in swimming speed during mild hypoxia and (2) depend on the severity of hypoxia.
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Affiliation(s)
- S B Poulsen
- Fisheries and Maritime Museum, DK-6710 Esbjerg V, Denmark.
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18
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Petersen LH, Gamperl AK. Cod (Gadus morhua) cardiorespiratory physiology and hypoxia tolerance following acclimation to low-oxygen conditions. Physiol Biochem Zool 2011; 84:18-31. [PMID: 21050128 DOI: 10.1086/657286] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Previous research has shown that hypoxia-acclimated Atlantic cod (Gadus morhua) have significantly reduced cardiac function but can consume more oxygen for a given cardiac output (Q). However, it is not known (1) which physiological changes permit a greater "oxygen pulse" (oxygen consumed per mL of blood pumped) in hypoxia-acclimated individuals or (2) whether chronic exposure to low-oxygen conditions improves the hypoxia tolerance of cod. Thus, we exposed normoxia- and hypoxia-acclimated (> 6 wk at a water oxygen partial pressure [P(w)O(2)] ~8-9 kPa) cod to a graded normoxia challenge until loss of equilibrium occurred while recording the following cardiorespiratory variables: oxygen consumption (MO(2)), ventilatory rate, cardiac function (Q, heart rate f(H), and stroke volume S(V)), ventral aortic blood pressure (P(VA)), venous oxygen partial pressure (P(v)O(2)) and oxygen content (C(v)O(2)), plasma catecholamines, and blood hemoglobin ([Hb]) and hematocrit (Hct). In addition, we performed in vitro hemoglobin oxygen binding curves to examine whether hypoxia acclimation influences hemoglobin functional properties. Numerous physiological adjustments occurred in vivo during the > 6 wk of hypoxia acclimation: that is, increased f(H), decreased S(V) and Q, elevated [Hb], enhanced tissue oxygen extraction (by 10% at a P(w)O(2) of 20 kPa), and a more robust stress response as evidenced by circulating catecholamine levels that were two to eight times higher when fish were acutely exposed to severe hypoxia. In contrast, chronic hypoxia had no significant effect on the affinity of hemoglobin for oxygen, on in vitro hemoglobin oxygen carrying capacity, or on the cod's hypoxia tolerance (H(crit); the P(w)O(2) at which the fish lost equilibrium, which was 4.3 ± 0.2 and 4.8 ± 0.3 kPa in normoxia- and hypoxia-acclimated fish, respectively). These data suggest that while chronic hypoxia results in numerous physiological adjustments, these changes do not improve the cod's capacity to tolerate low-oxygen conditions.
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Affiliation(s)
- L H Petersen
- Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, A1C 5S7 Newfoundland, Canada
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Behrens JW, Petersen JK, Aertebjerg G, Steffensen JF. Influence of moderate and severe hypoxia on the diurnal activity pattern of lesser sandeel Ammodytes tobianus. JOURNAL OF FISH BIOLOGY 2010; 77:538-551. [PMID: 20701639 DOI: 10.1111/j.1095-8649.2010.02697.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The influence of prolonged moderate (c. 60% oxygen saturation) and severe hypoxia (c. 35% oxygen saturation) on the diurnal activity pattern of sandeel Ammodytes tobianus was examined. In moderate hypoxia, the emerging and burying rates were significantly higher compared to that in normoxia, whereas fewer fish (c. 10%) were present in the water column. In contrast, severe hypoxia resulted in twice as many or more fish being present in the water column compared to that in normoxia. The increased number of swimming fish was not just a relative change due to an effect from hypoxia treatment, but the behaviour of the fish was also changed. The summed activity (emerging plus burying events) was lower in severe hypoxia compared to normoxia except during hours of dim light. All fish were buried during night-time, regardless of treatment, with the exception of some in severe hypoxia during the first couple of hours of darkness.
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Affiliation(s)
- J W Behrens
- Marine Biological Laboratory, University of Copenhagen, Strandpromenaden 5, DK-3000 Helsingør, Denmark.
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20
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Brady DC, Targett TE. Characterizing the escape response of juvenile summer flounder Paralichthys dentatus to diel-cycling hypoxia. JOURNAL OF FISH BIOLOGY 2010; 77:137-152. [PMID: 20646143 DOI: 10.1111/j.1095-8649.2010.02663.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Swimming speed, angular correlation and expected displacement were measured in juvenile summer flounder Paralichthys dentatus acclimated to either oxygen saturation (c. 7.8 mg O(2) l(-1); saturation-acclimated fish) or diel-cycling hypoxia (cycling between 11.0 and 2.0 mg O(2) l(-1)) for 10 days and subsequently exposed to more severe diel-cycling hypoxia (cycling between 7.0 and 0.4 mg O(2) l(-1)). Saturation-acclimated P. dentatus exhibited an active response to declining dissolved oxygen (DO) by increasing swimming speed, angular correlation and expected displacement to peak levels at 1.4 mg O(2) l(-1) that were 3.5, 5.5 and 4.2 fold, respectively, greater than those at DO saturation. Diel-cycling hypoxia-acclimated P. dentatus also exhibited an active response to declining DO, although it was relatively less pronounced. Diel-cycling hypoxia-acclimated P. dentatus swimming speed, however, still doubled as DO decreased from 7.0 to 2.8 mg O(2) l(-1). Diel-cycling hypoxia-acclimated P. dentatus did not recover as well from low DO exposure as did saturation-acclimated fish. This was reflected in their relatively more random swimming (low angular correlation between successive moves) and poor maintenance of rank order between individuals during the recovery phase. Even saturation-acclimated P. dentatus did not resume swimming at speeds observed at saturation until DO was 4.2 mg O(2) l(-1). Paralichthys dentatus were very sensitive to decreasing DO, even at DO levels that were not lethal or growth limiting. This sensitivity and their poor recovery may preclude juvenile P. dentatus from using highly productive nursery habitats affected by diel-cycling hypoxia.
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Affiliation(s)
- D C Brady
- Department of Civil and Environmental Engineering, University of Delaware, School of Marine Science and Policy, 700 Pilottown Rd, Lewes, DE 19958, USA.
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21
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Petersen LH, Gamperl AK. Effect of acute and chronic hypoxia on the swimming performance, metabolic capacity and cardiac function of Atlantic cod (Gadus morhua). ACTA ACUST UNITED AC 2010; 213:808-19. [PMID: 20154197 DOI: 10.1242/jeb.033746] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Low water oxygen content (hypoxia) is a common feature of many freshwater and marine environments. However, we have a poor understanding of the degree to which diminished cardiac function contributes to the reduction in fish swimming performance concomitant with acute exposure to hypoxia, or how fish cardiorespiratory physiology is altered by, or adapts to, chronic hypoxia. Thus, we acclimated adult Atlantic cod (Gadus morhua) to either approximately 8-9 kPa O(2) (40-45% air saturation) or approximately 21 kPa O(2) (100% air saturation; normoxia) for 6-12 weeks at 10 degrees C, and subsequently measured metabolic variables [routine oxygen consumption (M(O(2)), maximum (M(O(2)), metabolic scope] and cardiac function (cardiac output, Q; heart rate, f(H); and stroke volume, V(S)) in these fish during critical swimming speed (U(crit)) tests performed at both levels of water oxygenation. Although surgery (flow probe implantation) reduced the U(crit) of normoxia-acclimated cod by 14% (from 1.74 to 1.50 BL s(-1)) under normoxic conditions, exposure to acute hypoxia lowered the U(crit) of both groups (surgery and non-surgery) by approximately 30% (to 1.23 and 1.02 BL s(-1), respectively). This reduction in swimming performance was associated with large decreases in maximum M(O(2)) and metabolic scope (> or = 50%), and maximum f(H) and Q (by 16 and 22%), but not V(S). Long-term acclimation to hypoxia resulted in a significant elevation in normoxic metabolic rate as compared with normoxia-acclimated fish (by 27%), but did not influence normoxic or hypoxic values for U(crit), maximum M(O(2)) or metabolic scope. This was surprising given that resting and maximum values for Q were significantly lower in hypoxia-acclimated cod at both levels of oxygenation, because of lower values for V(S). However, hypoxia-acclimated cod were able to consume more oxygen for a given cardiac output. These results provide important insights into how fish cardiorespiratory physiology is impacted by short-term and prolonged exposure to hypoxia, and further highlight the tremendous capacity of the fish cardiorespiratory system to deal with environmental challenges.
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Affiliation(s)
- L H Petersen
- Ocean Sciences Centre, Memorial University of Newfoundland, St John's, NL, Canada, A1C 5S7
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22
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Neuenfeldt S, Andersen KH, Hinrichsen HH. Some Atlantic cod Gadus morhua in the Baltic Sea visit hypoxic water briefly but often. JOURNAL OF FISH BIOLOGY 2009; 75:290-4. [PMID: 20738498 DOI: 10.1111/j.1095-8649.2009.02281.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Individual behaviour of Atlantic cod Gadus morhua in the presence of hypoxic water was measured in situ in the vertically stratified Bornholm Basin of the Baltic Sea. Considering all recaptured individuals, the use of hypoxic habitat was comparable to data derived by traditional survey data, but some G. morhua had migrated towards the centre of the c.100 m deep basin and spent about a third of their time at oxygen saturation <50%, possibly to forage on zoobenthos. Maximal residence time per visit in such hypoxic water was limited to a few hours, allowing for the digestion of consumed prey items in waters with sufficient dissolved oxygen.
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Affiliation(s)
- S Neuenfeldt
- Technical University of Denmark, National Institute of Aquatic Resources, Charlottenlund Castle, DK-2920 Charlottenlund, Denmark.
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23
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Sanderson H, Fauser P, Thomsen M, Sørensen PB. Human health risk screening due to consumption of fish contaminated with chemical warfare agents in the Baltic Sea. JOURNAL OF HAZARDOUS MATERIALS 2009; 162:416-422. [PMID: 18573611 DOI: 10.1016/j.jhazmat.2008.05.059] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2008] [Revised: 05/09/2008] [Accepted: 05/12/2008] [Indexed: 05/26/2023]
Abstract
Chemical warfare agents (CWAs) have been disposed of in various fashions over the past decades. Significant amounts of CWA, roughly 11,000ton, have been dumped in the Baltic Sea east of the island Bornholm following the disarmament of Germany after World War II. This has caused concerns over potential human and environmental health risks, and resulted in restrictions on fishing in the dumpsite area. The purpose of this paper is to assess the potential indirect human health risks due to consumption of CWA-contaminated fish from the dumpsite area east of Bornholm. Earlier studies suggest that the fish community may be at risk from CWA exposure in the Bornholm basin. Moreover, elevated frequencies of lesions on fish caught in a CWA dumpsite in the Mediterranean Sea have been observed. The fish at the Mediterranean dumpsite had elevated total arsenic (As) concentrations in their tissue, and elevated total As levels were also observed in the sediment. Elevated total sediment As concentrations have also been recorded in CWA dumpsites in the Skagerrak and the Baltic Sea. Triphenylarsine and sulfur mustard gas (Yperite) are the CWAs with the greatest indirect human health risk potential. There are recognized uncertainties concerning Yperite's and CWA-derived arsenical's fate and speciation in the environment, as well as their inherent toxicity, warranting caution and further site-specific environmental and human health risk assessments of CWAs dumped in the Bornholm basin.
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Affiliation(s)
- Hans Sanderson
- Department of Policy Analysis, University of Aarhus Frederiksborgvej 399, Post Box 358, DK-4000 Roskilde, Denmark.
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24
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25
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Claireaux G, Lefrançois C. Linking environmental variability and fish performance: integration through the concept of scope for activity. Philos Trans R Soc Lond B Biol Sci 2008; 362:2031-41. [PMID: 17472923 PMCID: PMC2442852 DOI: 10.1098/rstb.2007.2099] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Investigating the biological mechanisms linking environmental variability to fish production systems requires the disentangling of the interactions between habitat, environmental adaptation and fitness. Since the number of environmental variables and regulatory processes is large, straightening out the environmental influences on fish performance is intractable unless the mechanistic analysis of the 'fish-milieu' system is preceded by an understanding of the properties of that system. While revisiting the key points in our currently poorly integrated understanding of fish ecophysiology, we have highlighted the explanatory potential contained within Fry's (Fry 1947 Univ. Toronto Stud. Biol. Ser. 55, 1-62) concept of metabolic scope and categorization of environmental factors. These two notions constitute a pair of powerful tools for conducting an external (at the emerging property level) analysis of the environmental influences on fish, as well as an internal (mechanistic) examination of the behavioural, morphological and physiological processes involved. Using examples from our own and others work, we have tried to demonstrate that Fry's framework represents a valuable conceptual basis leading to a broad range of testable ecophysiological hypotheses.
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Affiliation(s)
- Guy Claireaux
- Centre National de la Recherche Scientifique, Station Méditerranéenne de l'Environnement Littoral, 1 Quai de la Daurade, Sète 34200, France.
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26
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Chabot D, Claireaux G. Environmental hypoxia as a metabolic constraint on fish: the case of Atlantic cod, Gadus morhua. MARINE POLLUTION BULLETIN 2008; 57:287-294. [PMID: 18508091 DOI: 10.1016/j.marpolbul.2008.04.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Revised: 03/31/2008] [Accepted: 04/02/2008] [Indexed: 05/26/2023]
Abstract
Hypoxia is known to provoke a wide range of effects on aquatic animals. Here we use laboratory and field data on Atlantic cod, Gadus morhua, to illustrate that many of these responses can be explained within the metabolic scope (MS) framework, i.e. taking into account the directive and limiting effects of dissolved oxygen (DO) on the ability of animals to acquire energy for growth and activity. A MS model for cod shows that scope for activity (swimming, feeding, etc.) is proportional to DO and becomes nil, jeopardising survival, when DO is < approximately 20% air saturation. Laboratory studies have confirmed this lethal threshold and demonstrated that growth and food ingestion were significantly reduced below 70% sat. This loss of appetite has been linked to a reduction of the peak value and an increase in duration of postprandial metabolism, in agreement with the MS model. Dwindling MS during hypoxia imposes an upper limit to swimming performance. Cod may also opt to reduce spontaneous swimming activity to spare oxygen for other activities such as digestion. In the Kattegat, the Baltic Sea, and the Gulf of St. Lawrence, eastern Canada, cod completely avoid waters where their MS is near zero. Furthermore, cod density increases exponentially with DO up to approximately 70% sat in the Gulf of St. Lawrence. Although hypoxia results in other direct and indirect effects as well, the MS framework allows modelling of many of the responses to hypoxia for individual cod that ought to be reflected at the population and community levels. The MS framework is also useful to compare species responses. We show that the impact of hypoxia on MS is similar, when expressed as a proportion of MS in normoxia, in cod, European sea bass (Dicentrarchus labrax), the common sole (Solea solea) and turbot (Psetta maxima). Data are required for other species to evaluate how general these findings are.
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Affiliation(s)
- D Chabot
- Direction des sciences halieutiques et aquaculture, Ministère des Pêches et des Océans, Institut Maurice-Lamontagne, C.P. 1000, Mont-Joli, QC, Canada G5H 3Z4.
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27
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Mendonça PC, Genge AG, Deitch EJ, Gamperl AK. Mechanisms responsible for the enhanced pumping capacity of the in situ winter flounder heart (Pseudopleuronectes americanus). Am J Physiol Regul Integr Comp Physiol 2007; 293:R2112-9. [PMID: 17761512 DOI: 10.1152/ajpregu.00202.2007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In situ Starling and power output curves and in vitro pressure-volume curves were determined for winter flounder hearts, as well as the hearts of two other teleosts (Atlantic salmon and cod). In situ maximum cardiac output was not different between the three species (approximately 62 ml.min(-1).kg(-1)). However, because of the small size of the flounder heart, maximum stroke volume per milliliter per gram ventricle was significantly greater (2.3) compared with cod (1.7) and salmon (1.4) and is the highest reported for teleosts. The maximum power output of the flounder heart (7.6 mW/g) was significantly lower than that measured in the salmon (9.7) and similar to the cod (7.8) but was achieved at a much lower output pressure (4.9 vs. 8.0 and 6.2 kPa, respectively). Although the flounder heart could not perform resting levels of cardiac function at subambient pressures, it was much more sensitive to filling pressure, a finding supported by pressure-volume curves, which showed that the flounder's heart chambers were more compliant. Finally, we report that the flounder's bulbus:ventricle mass ratio (0.59) was significantly higher than in the cod (0.37) and salmon (0.22). These data, which support previous studies suggesting that the flatfish cardiovascular system is a high-volume, low-pressure design, show that vis-à-fronte filling is not important in flatfish, and that some fish can achieve high levels of cardiac output by vis-à-tergo filling alone; and suggest that a large compliant bulbus assists the flounder heart in delivering extremely large stroke volumes at pressures that do not become limiting.
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Affiliation(s)
- Paula C Mendonça
- Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, NL, Canada A1C 5S7
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28
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Sloman KA, Wood CM, Scott GR, Wood S, Kajimura M, Johannsson OE, Almeida-Val VMF, Val AL. Tribute to R. G. Boutilier: The effect of size on the physiological and behavioural responses of oscar,Astronotus ocellatus, to hypoxia. J Exp Biol 2006; 209:1197-205. [PMID: 16547292 DOI: 10.1242/jeb.02090] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARYThe physiological and behavioural responses of two size groups of oscar(Astronotus ocellatus) to hypoxia were studied. The physiological responses were tested by measuring ṀO2 during decreasing environmental oxygen tensions. Larger oscars were better able to maintain oxygen consumption during a decrease in PO2, regulating routine ṀO2 to a significantly lower PO2 threshold (50 mmHg)than smaller oscars (70 mmHg). Previous studies have also demonstrated a longer survival time of large oscars exposed to extreme hypoxia, coupled with a greater anaerobic enzymatic capability. Large oscars began aquatic surface respiration (ASR) at the oxygen tension at which the first significant decrease in ṀO2was seen (50 mmHg). Interestingly, smaller oscars postponed ASR to around 22 mmHg, well beyond the PO2 at which they switched from oxyregulation to oxyconformation. Additionally, when given the choice between an hypoxic environment containing aquatic macrophyte shelter and an open normoxic environment, small fish showed a greater preference for the hypoxic environment. Thus shelter from predators appears particularly important for juveniles, who may accept a greater physiological compromise in exchange for safety. In response to hypoxia without available shelter, larger fish reduced their level of activity (with the exception of aggressive encounters) to aid metabolic suppression whereas smaller oscars increased their activity, with the potential benefit of finding oxygen-rich areas.
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Affiliation(s)
- Katherine A Sloman
- School of Biological Sciences, University of Plymouth, Devon, PL4 8AA, UK.
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Staples JF, Webber DM, Boutilier RG. Environmental hypoxia does not constrain the diurnal depth distribution of free-swimming Nautilus pompilius. Physiol Biochem Zool 2004; 76:644-51. [PMID: 14671712 DOI: 10.1086/376428] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2003] [Indexed: 11/03/2022]
Abstract
The behaviour of Nautilus pompilius swimming freely in a controlled mesocosm (tower tank, 4 m diameter x 10.5 m deep) was monitored using ultrasonic depth telemetry. Initially depths were monitored in water equilibrated with air. Then the bottom 3.5 m were rendered hypoxic (Po(2) <20 mmHg) and depths monitored again. A thermocline at 7-m depth (17 degrees C below, 20 degrees C above) prevented mixing with the top, normoxic water. Mean depth was significantly greater during the light phase (8.9 m) of the 12L : 12D photoperiod than the dark phase (5.6 m), but this was not affected by hypoxia. During the light phase animals preferred the bottom 2.5 m of the tank but showed no specific preference for any depth range during the dark phase. Hypoxia did not alter these patterns of depth preference, though one animal made regular excursions toward normoxic water during the light phase. Vertical swimming activity was almost twofold greater during the dark phase and was not affected by hypoxia. These data suggest that, at least over the short term, Nautilus are not constrained from entering areas with low dissolved oxygen. This hypoxia tolerance may be attributed to the large onboard oxygen stores and suppressed metabolism during hypoxia.
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Affiliation(s)
- James F Staples
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, England.
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30
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Bunt CM, Cooke SJ, Schreer JF, Philipp DP. Effects of incremental increases in silt load on the cardiovascular performance of riverine and lacustrine rock bass, Ambloplites rupestris. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2004; 128:437-444. [PMID: 14720485 DOI: 10.1016/j.envpol.2003.09.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2003] [Accepted: 09/12/2003] [Indexed: 05/24/2023]
Abstract
Rock bass (Ambloplites rupestris) are a widespread centrarchid species with both riverine and lacustrine populations. After precipitation events, rivers often carry elevated silt loads, where as lakes generally remain free from suspended silt and sediment. To examine the physiological effects of silt on rock bass, we conducted a series of experiments using fish from Lake Opinicon and the Grand River in Ontario. Ultrasonic Doppler flow probes were surgically affixed around the ventral aorta to monitor cardiovascular performance. After recovery from surgery replicated treatment groups were exposed to incremental increases in silt load (made from bentonite slurry), while cardiac output and its two components, heart rate and stroke volume, were measured simultaneously. Although both groups of rock bass responded significantly to low concentrations of silt (10 NTU), the response by riverine rock bass was rapidly extinguished by acclimation or physiological adjustment. Compensatory mechanisms to minimize cardiac (and respiratory) disruption attributable to increases in suspended silt appear to be inherent in rock bass of riverine origin. These fish appear to fully compensate for interference in gas exchange at the gill surfaces 60 min after initial exposure. In contrast, individual lacustrine rock bass were highly variable in their response to elevated silt concentrations. Changes in stroke volume and cardiac output suggested no clear compensatory mechanism or strategy to cope with increased silt levels.
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Affiliation(s)
- Christopher M Bunt
- Biotactic Inc, 691 Hidden Valley Rd, Kitchener, Ontario, Canada N2C 2S4.
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31
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Sullivan AB, Jager HI, Myers R. Modeling white sturgeon movement in a reservoir: the effect of water quality and sturgeon density. Ecol Modell 2003. [DOI: 10.1016/s0304-3800(03)00169-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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