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Aaskov ML, Nelson D, Lauridsen H, Huong DTT, Ishimatsu A, Crossley DA, Malte H, Bayley M. Do air-breathing fish suffer branchial oxygen loss in hypoxic water? Proc Biol Sci 2023; 290:20231353. [PMID: 37700647 PMCID: PMC10498054 DOI: 10.1098/rspb.2023.1353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 08/18/2023] [Indexed: 09/14/2023] Open
Abstract
In hypoxia, air-breathing fish obtain O2 from the air but continue to excrete CO2 into the water. Consequently, it is believed that some O2 obtained by air-breathing is lost at the gills in hypoxic water. Pangasionodon hypophthalmus is an air-breathing catfish with very large gills from the Mekong River basin where it is cultured in hypoxic ponds. To understand how P. hypophthalmus can maintain high growth in hypoxia with the presumed O2 loss, we quantified respiratory gas exchange in air and water. In severe hypoxia (PO2: ≈ 1.5 mmHg), it lost a mere 4.9% of its aerial O2 uptake, while maintaining aquatic CO2 excretion at 91% of the total. Further, even small elevations in water PO2 rapidly reduced this minor loss. Charting the cardiovascular bauplan across the branchial basket showed four ventral aortas leaving the bulbus arteriosus, with the first and second gill arches draining into the dorsal aorta while the third and fourth gill arches drain into the coeliacomesenteric artery supplying the gut and the highly trabeculated respiratory swim-bladder. Substantial flow changes across these two arterial systems from normoxic to hypoxic water were not found. We conclude that the proposed branchial oxygen loss in air-breathing fish is likely only a minor inefficiency.
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Affiliation(s)
- Magnus L. Aaskov
- Division of Zoophysiology, Department of Biology, Aarhus University, 8000C Aarhus, Denmark
| | - Derek Nelson
- Department of Biological Sciences, University of North Texas, 1155 Union Circle, Denton, TX 76203, USA
| | - Henrik Lauridsen
- Comparative Medicine Lab, Department of Clinical Medicine, Aarhus, Denmark
| | - Do Thi Thanh Huong
- College of Aquaculture and Fisheries, Can Tho University, Can Tho, Vietnam
| | - Atsushi Ishimatsu
- Institute for East China Sea Research, Nagasaki University, Nagasaki, Japan
| | - Dane A. Crossley
- Department of Biological Sciences, University of North Texas, 1155 Union Circle, Denton, TX 76203, USA
| | - Hans Malte
- Division of Zoophysiology, Department of Biology, Aarhus University, 8000C Aarhus, Denmark
| | - Mark Bayley
- Division of Zoophysiology, Department of Biology, Aarhus University, 8000C Aarhus, Denmark
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2
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Ramírez JFP, Amanajás RD, Val AL. Ammonia Increases the Stress of the Amazonian Giant Arapaima gigas in a Climate Change Scenario. Animals (Basel) 2023; 13:1977. [PMID: 37370487 DOI: 10.3390/ani13121977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 06/02/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023] Open
Abstract
Ammonia is toxic to fish, and when associated with global warming, it can cause losses in aquaculture. In this study, we investigated the physiological and zootechnical responses of Arapaima gigas to the current scenarios and to RCP8.5, a scenario predicted by the IPCC for the year 2100 which is associated with high concentrations of environmental ammonia (HEA). Forty-eight chipped juvenile A. gigas were distributed in two experimental rooms (current scenario and RCP8.5) in aquariums with and without the addition of ammonia (0.0 mM and 2.44 mM) for a period of 30 days. The HEA, the RCP8.5 scenario, and the association of these factors affects the zootechnical performance, the ionic regulation pattern, and the levels of ammonia, glucose, triglycerides, sodium, and potassium in pirarucu plasma. The branchial activity of H+-ATPase was reduced and AChE activity increased, indicating that the species uses available biological resources to prevent ammonia intoxication. Thus, measures such as monitoring water quality in regard to production, densities, and the feed supplied need to be more rigorous and frequent in daily management in order to avoid the accumulation of ammonia in water, which, in itself, proved harmful and more stressful to the animals subjected to a climate change scenario.
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Affiliation(s)
- José Fernando Paz Ramírez
- Programa de Pós-Graduação em Aquicultura, Universidade Nilton Lins, Avenida Professor Nilton Lins, 3259, Parques das Laranjeiras, Manaus CEP 69058-030, Brazil
| | - Renan Diego Amanajás
- Laboratório de Ecofisiologia e Evolução Molecular, Instituto Nacional de Pesquisas da Amazônia, Avenida André Araújo, 2936, Petrópolis, Manaus CEP 69067-375, Brazil
- Programa de Pós-Graduação em Biologia de Água Doce e Pesca Interior, Instituto Nacional de Pesquisas da Amazônia, Avenida André Araújo, 2936, Petrópolis, Manaus CEP 69067-375, Brazil
| | - Adalberto Luis Val
- Laboratório de Ecofisiologia e Evolução Molecular, Instituto Nacional de Pesquisas da Amazônia, Avenida André Araújo, 2936, Petrópolis, Manaus CEP 69067-375, Brazil
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3
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Zaccone G, Capillo G, Aragona M, Alesci A, Cupello C, Lauriano ER, Guerrera MC, Kuciel M, Zuwala K, Germana A, Icardo JM. Gill structure and neurochemical markers in the African bonytongue (Heterotis niloticus): A preliminary study. Acta Histochem 2022; 124:151954. [PMID: 36174310 DOI: 10.1016/j.acthis.2022.151954] [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: 04/26/2022] [Revised: 09/13/2022] [Accepted: 09/15/2022] [Indexed: 11/01/2022]
Abstract
We have conducted a morphological and immunohistochemical study of the gills of juvenile specimens of the obligate air-breathing fish Heterotis niloticus. The study has been performed under normoxic and hypoxic conditions. The gills showed a reduced respiratory surface area by development of an interlamellar cellular mass (ILCM). The ILCM persisted without changes under both normoxia and hypoxia. Neuroepithelial cells (NECs), the major oxygen and hypoxia sensing cell type, were located in the distal end of the gill filaments and along the ILCM edges. These cells expressed 5HT, the neuronal isoform of the nitric oxide synthase (nNOS) and the vesicular acetylcholine transporter (VAChT). Furthermore, NECs appeared associated with nitrergic nerve fibres. The O2 levels did not modify the location, number or the immunohistochemical characteristics of NECs. Pavement cells covering the ILCM were also positive to nNOS and VAChT. The mechanisms of O2 sensing in the gills of Heterotis appears to involve several cell populations, the release of multiple neurotransmitters and a diversity of excitatory, inhibitory and modulatory mechanisms.
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Affiliation(s)
- Giacomo Zaccone
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy.
| | - Gioele Capillo
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy; Institute for Marine Biological Resources and Biotechnology (IRBIM), National Research Council (CNR), 98122 Messina, Italy.
| | - Marialuisa Aragona
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy.
| | - Alessio Alesci
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale F. Stagno d'Alcontres 31, I-98166 Messina, Italy
| | - Camila Cupello
- Departamento de Zoologia, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier, 524, 20550-900, Rio de Janeiro, Brazil.
| | - Eugenia Rita Lauriano
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale F. Stagno d'Alcontres 31, I-98166 Messina, Italy.
| | - Maria Cristina Guerrera
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy.
| | - Michal Kuciel
- Poison Information Centre, Department of Toxicology and Environmental Disease, Faculty of Medicine, Jagellonian University, Kopernika 15, 30-501 Krakòw, Poland.
| | - Kristina Zuwala
- Department of Comparative Anatomy, Institute of Zoology and Biomedical Researches, Faculty of Biology, Jagiellonian University in Krakow, Krakow, Poland.
| | - Antonino Germana
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy.
| | - Josè Manuel Icardo
- Department of Anatomy and Cell Biology, Poligono de Cazoña, Faculty of Medicine, University of Cantabria, Santander, Spain.
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4
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Weber RE, Damsgaard C, Fago A, Val AL, Moens L. Ontogeny of hemoglobin‑oxygen binding and multiplicity in the obligate air-breathing fish Arapaima gigas. Comp Biochem Physiol A Mol Integr Physiol 2022; 268:111190. [PMID: 35331911 DOI: 10.1016/j.cbpa.2022.111190] [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: 02/15/2022] [Revised: 03/15/2022] [Accepted: 03/15/2022] [Indexed: 10/18/2022]
Abstract
The evolutionary and ontogenetic changes from water- to air-breathing result in major changes in the cardiorespiratory systems. However, the potential changes in hemoglobin's (Hb) oxygen binding properties during ontogenetic transitions to air-breathing remain poorly understood. Here we investigated Hb multiplicity and O2 binding in hemolysates and Hb components from juveniles and adults of the obligate air-breathing pirarucu (Arapaima gigas) that starts life as water-breathing hatchlings. Contrasting with previous electrophoresis studies that report one or two isoHbs in adults, isoelectric focusing (IEF) resolved the hemolysates from both stages into four major bands, which exhibited identical O2 binding properties (i.e. O2 affinities, cooperativity coefficients, and sensitivities to pH and the major organic phosphate effectors), also as compared to the cofactor-free hemolysates. Of note, the multiplicity pattern recurred upon reanalyses of the most-abundant fractions isolated from the juvenile and the adult stages, suggesting possible stabilization of different quaternary states with different isoelectric points during the purification procedure. The study demonstrates unchanged Hb-O2 binding properties during development, despite the pronounced differences in O2 availability between the two media, which harmonizes with findings based on a broader spectrum of interspecific comparisons. Taken together, these results disclose that obligate air-breathing in Arapaima is not contingent upon changes in Hb multiplicity and O2 binding characteristics.
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Affiliation(s)
- Roy E Weber
- Zoophysiology, Department of Biology, Aarhus University, Aarhus, Denmark.
| | - Christian Damsgaard
- Zoophysiology, Department of Biology, Aarhus University, Aarhus, Denmark; Aarhus Institute of Advanced Studies, Aarhus University, Aarhus, Denmark
| | - Angela Fago
- Zoophysiology, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Adalberto L Val
- Brazilian National Institute for Research of the Amazon, Manaus, Amazonas, Brazil
| | - Luc Moens
- Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
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5
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Luis Val A, Wood CM. Global change and physiological challenges for fish of the Amazon today and in the near future. J Exp Biol 2022; 225:275450. [PMID: 35582942 DOI: 10.1242/jeb.216440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Amazonia is home to 15% (>2700, in 18 orders) of all the freshwater fish species of the world, many endemic to the region, has 65 million years of evolutionary history and accounts for 20% of all freshwater discharge to the oceans. These characteristics make Amazonia a unique region in the world. We review the geological history of the environment, its current biogeochemistry and the evolutionary forces that led to the present endemic fish species that are distributed amongst three very different water types: black waters [acidic, ion-poor, rich in dissolved organic carbon (DOC)], white waters (circumneutral, particle-rich) and clear waters (circumneutral, ion-poor, DOC-poor). The annual flood pulse is the major ecological driver for fish, providing feeding, breeding and migration opportunities, and profoundly affecting O2, CO2 and DOC regimes. Owing to climate change and other anthropogenic pressures such as deforestation, pollution and governmental mismanagement, Amazonia is now in crisis. The environment is becoming hotter and drier, and more intense and frequent flood pulses are now occurring, with greater variation between high and low water levels. Current projections are that Amazon waters of the near future will be even hotter, more acidic, darker (i.e. more DOC, more suspended particles), higher in ions, higher in CO2 and lower in O2, with many synergistic effects. We review current physiological information on Amazon fish, focusing on temperature tolerance and ionoregulatory strategies for dealing with acidic and ion-poor environments. We also discuss the influences of DOC and particles on gill function, the effects of high dissolved CO2 and low dissolved O2, with emphasis on water- versus air-breathing mechanisms, and strategies for pH compensation. We conclude that future elevations in water temperature will be the most critical factor, eliminating many species. Climate change will likely favour predominantly water-breathing species with low routine metabolic rates, low temperature sensitivity of routine metabolic rates, high anaerobic capacity, high hypoxia tolerance and high thermal tolerance.
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Affiliation(s)
- Adalberto Luis Val
- Laboratory of Ecophysiology and Molecular Evolution, Brazilian National Institute for Research of the Amazon, Manaus, Brazil, 69080-971
| | - Chris M Wood
- Department of Zoology, University of British Columbia, Vancouver, BC, CanadaV6T 1Z4.,Department of Biology, McMaster University, Hamilton, ON, CanadaL8S 4K1
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6
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Aaskov ML, Jensen RJ, Skov PV, Wood CM, Wang T, Malte H, Bayley M. Arapaima gigas maintains gas exchange separation in severe aquatic hypoxia but does not suffer branchial oxygen loss. J Exp Biol 2022; 225:274291. [PMID: 35132994 DOI: 10.1242/jeb.243672] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 02/02/2022] [Indexed: 11/20/2022]
Abstract
One of the most air-reliant obligate air-breathing fish is the South American Arapaima gigas, with substantially reduced gills impeding gas diffusion, thought to be a result of recurring aquatic hypoxia in its habitat. In normoxic water, A. gigas is reported to satisfy 70-80% of its O2 requirement from the air while excreting 60-90% of its CO2 to the water. If this pattern of gas exchange were to continue in severely hypoxic water, O2 loss at the gills would be expected. We hypothesized therefore that partitioning of CO2 would shift to the air phase in severe aquatic hypoxia eliminating the risk of branchial O2 loss. By adapting a respirometer designed to measure aquatic MO2/MCO2 we were able to run intermittent closed respirometry on both water and air phase for both of these gasses as well as sample water for N-waste measurements (ammonia-N, urea-N) so as to calculate metabolic fuel utilization. In contrast to our prediction, we found that partitioning of CO2 excretion changed little between normoxia and severe hypoxia (83% vs 77% aquatic excretion respectively) and at the same time there was no evidence of branchial O2 loss in hypoxia. This indicates that A. gigas can utilize distinct transfer pathways for O2 and CO2. Routine and standard MO2, N-waste excretion, and metabolic fuel utilization did not change with water oxygenation. Metabolism was fueled mostly by protein oxidation (53%) while carbohydrates and lipids accounted for 27% and 20% respectively.
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Affiliation(s)
- Magnus L Aaskov
- Zoophysiology, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Rasmus J Jensen
- Zoophysiology, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Peter Vilhelm Skov
- Technical University of Denmark, DTU Aqua, Section for Aquaculture, Hirtshals, Denmark
| | - Chris M Wood
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Tobias Wang
- Zoophysiology, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Hans Malte
- Zoophysiology, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Mark Bayley
- Zoophysiology, Department of Biology, Aarhus University, Aarhus, Denmark
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7
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Frommel AY, Kwan GT, Prime KJ, Tresguerres M, Lauridsen H, Val AL, Gonçalves LU, Brauner CJ. Changes in gill and air-breathing organ characteristics during the transition from water- to air-breathing in juvenile Arapaima gigas. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2021; 335:801-813. [PMID: 33819380 DOI: 10.1002/jez.2456] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 02/10/2021] [Accepted: 02/25/2021] [Indexed: 01/01/2023]
Abstract
The obligate air-breathing Amazonian fish, Arapaima gigas, hatch as water-breathing larvae but with development, they modify their swim bladder to an air-breathing organ (ABO) while reducing their gill filaments to avoid oxygen loss. Here, we show that significant changes already take place between 4 weeks (1.6 g) and 11 weeks (5 g) post hatch, with a reduction in gill lamellar surface area, increase in gill diffusion distance, and proliferation of the parenchyma in the ABO. By using a variety of methods, we quantified the surface area and diffusion distances of the gills and skin, and the swim bladder volume and anatomical complexity from hatch to 11-week-old juveniles. In addition, we identified the presence of two ionocyte types in the gills and show how these change with development. Until 1.6 g, A. gigas possess only the H+ -excreting/Na+ -absorbing type, while 5-g fish and adults have an additional ionocyte which likely absorbs H+ and Cl- and excretes HCO3 - . The ionocyte density on the gill filaments increased with age and is likely a compensatory mechanism for maintaining ion transport while reducing gill surface area. In the transition from water- to air-breathing, A. gigas likely employs a trimodal respiration utilizing gills, skin, and ABO and thus avoid a respiratory-ion regulatory compromise at the gills.
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Affiliation(s)
- Andrea Y Frommel
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada.,Institute of Oceans and Fisheries, University of British Columbia, Vancouver, British Columbia, Canada
| | - Garfield T Kwan
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Kaelan J Prime
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Martin Tresguerres
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Henrik Lauridsen
- Department of Clinical Medicine (Comparative Medicine Lab), Aarhus University, Aarhus, Denmark
| | - Adalberto L Val
- Brazilian National Institute for Research of the Amazon, Manaus, Amazonas, Brazil
| | - Ligia U Gonçalves
- Brazilian National Institute for Research of the Amazon, Manaus, Amazonas, Brazil
| | - Colin J Brauner
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
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8
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Survival, Growth, and Development in the Early Stages of the Tropical Gar Atractosteus tropicus: Developmental Critical Windows and the Influence of Temperature, Salinity, and Oxygen Availability. FISHES 2021. [DOI: 10.3390/fishes6010005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Alterations in fish developmental trajectories occur in response to genetic and environmental changes, especially during sensitive periods of development (critical windows). Embryos and larvae of Atractosteus tropicus were used as a model to study fish survival, growth, and development as a function of temperature (28 °C control, 33 °C, and 36 °C), salinity (0.0 ppt control, 4.0 ppt, and 6.0 ppt), and air saturation (control ~95% air saturation, hypoxia ~30% air saturation, and hyperoxia ~117% air saturation) during three developmental periods: (1) fertilization to hatch, (2) day 1 to day 6 post hatch (dph), and (3) 7 to 12 dph. Elevated temperature, hypoxia, and hyperoxia decreased survival during incubation, and salinity at 2 and 3 dph. Growth increased in embryos incubated at elevated temperature, at higher salinity, and in hyperoxia but decreased in hypoxia. Changes in development occurred as alterations in the timing of hatching, yolk depletion, acceptance of exogenous feeding, free swimming, and snout shape change, especially at high temperature and hypoxia. Our results suggest identifiable critical windows of development in the early ontogeny of A. tropicus and contribute to the knowledge of fish larval ecology and the interactions of individuals × stressors × time of exposure.
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9
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Gonzalez RJ, Hsu R, Mahaffey L, Rebagliatti D, Shami J. Examination of ionoregulatory characteristics of South American cichlids. Comp Biochem Physiol A Mol Integr Physiol 2020; 253:110854. [PMID: 33248286 DOI: 10.1016/j.cbpa.2020.110854] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/20/2020] [Accepted: 11/21/2020] [Indexed: 11/16/2022]
Abstract
We examined ionoregulatory traits of four cichlid species from South America, oscars (Astronotus ocellatus), Tapajos cichlids (Geophagus sp.), Macmaster's dwarf cichlids (Apistogramma macmasteri), and keyhole cichlids (Cleithracara maronii), all inhabitants of ion-poor waters. Km values for Na+ transport in fish held in 100 μmol L-1 Na+ water ranged from 49 to 143 μmol L-1, and Jmax values spanned 450 to 1205 nmol g-1 h-1. After one month in 1000 μmol L-1 Na+ water, kinetic parameters for Na+ uptake in three of the four species acclimated, but only oscars displayed the "typical" pattern of higher Km and lower Jmax values. Low pH water inhibited Na+ uptake (JinNa) in all, and stimulated Na+ efflux (JoutNa) 2.5 to 3.5-fold in three of the four species. Oscars alone had had a measurable JinNa at pH 3.5 and no stimulation of JoutNa. We measured JinNa in oscars and keyhole cichlids during exposure to 100 μmol L-1 Ethoxzolemide (EZ), an inhibitor of carbonic anhydrase, and 1 mmol L-1 NH4Cl (HEA). EZ inhibited JinNa by about 50% and HEA reduced JinNa by 80-90%. These results suggest that Na+ uptake involves H+ extrusion. Acute exposure to 1 μmol L-1 CuSO4 and 60 nmol L-1 AgNO3 inhibited JinNa in both species by 30-85%. Exposure of oscars to 5-fold higher concentrations of both metals did not further inhibit JinNa, but it did stimulate JoutNa 50-150%. The response to metals of both species are similar to other species that have been examined.
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Affiliation(s)
- R J Gonzalez
- Department of Biology, University of San Diego, 5998 Alcalá Park, San Diego, CA 92110, United States of America.
| | - R Hsu
- Department of Biology, University of San Diego, 5998 Alcalá Park, San Diego, CA 92110, United States of America
| | - L Mahaffey
- Department of Biology, University of San Diego, 5998 Alcalá Park, San Diego, CA 92110, United States of America
| | - D Rebagliatti
- Department of Biology, University of San Diego, 5998 Alcalá Park, San Diego, CA 92110, United States of America
| | - J Shami
- Department of Biology, University of San Diego, 5998 Alcalá Park, San Diego, CA 92110, United States of America
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10
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Wood CM, Pelster B, Braz-Mota S, Val AL. Gills versus kidney for ionoregulation in the obligate air-breathing Arapaima gigas, a fish with a kidney in its air-breathing organ. J Exp Biol 2020; 223:jeb232694. [PMID: 32895323 DOI: 10.1242/jeb.232694] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 08/19/2020] [Indexed: 12/19/2022]
Abstract
In Arapaima gigas, an obligate air-breather endemic to ion-poor Amazonian waters, a large complex kidney runs through the air-breathing organ (ABO). Previous indirect evidence suggested that the kidney, relative to the small gills, may be exceptionally important in ionoregulation and nitrogen (N) waste excretion, with support of kidney function by direct O2 supply from the airspace. We tested these ideas by continuous urine collection and gill flux measurements in ∼700 g fish. ATPase activities were many-fold greater in kidney than gills. In normoxia, gill Na+ influx and efflux were in balance, with net losses of Cl- and K+ Urine flow rate (UFR, ∼11 ml kg-1 h-1) and urinary ions (< 0.2 mmol l-1) were exceptional, with [urine]:[plasma] ratios of 0.02-0.002 for K+, Na+, and Cl-, indicating strong reabsorption with negligible urinary ion losses. Urinary [ammonia] was very high (10 mmol l-1, [urine]:[plasma] ∼17) indicating strong secretion. The kidney accounted for 21-24% of N excretion, with ammonia dominating (95%) over urea-N through both routes. High urinary [ammonia] was coupled to high urinary [HCO3-]. Aerial hypoxia (15.3 kPa) and aerial hyperoxia (>40.9 kPa) had no effects on UFR, but both inhibited branchial Na+ influx, revealing novel aspects of the osmorespiratory compromise. Aquatic hypoxia (4.1 kPa), but not aquatic hyperoxia (>40.9 kPa), inhibited gill Na+ influx, UFR and branchial and urinary ammonia excretion. We conclude that the kidney is more important than gills in ionoregulation, and is significant in N excretion. Although not definitive, our results do not indicate direct O2 supply from the ABO for kidney function.
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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
| | - Bernd Pelster
- Institute of Zoology, University of Innsbruck, Innsbruck A-6020, Austria
- Center for Molecular Biosciences, University Innsbruck, Innsbruck A-6020, Austria
| | - Susana Braz-Mota
- Laboratory of Ecophysiology and Molecular Evolution, Brazilian National Institute for Research of the Amazon, Manaus 69080-971, Brazil
| | - Adalberto L Val
- Laboratory of Ecophysiology and Molecular Evolution, Brazilian National Institute for Research of the Amazon, Manaus 69080-971, Brazil
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11
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Cellular oxygen consumption, ROS production and ROS defense in two different size-classes of an Amazonian obligate air-breathing fish (Arapaima gigas). PLoS One 2020; 15:e0236507. [PMID: 32730281 PMCID: PMC7392269 DOI: 10.1371/journal.pone.0236507] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 07/07/2020] [Indexed: 12/22/2022] Open
Abstract
In air-breathing fish a reduction of gill surface area reduces the danger of losing oxygen taken up in the air-breathing organ (ABO) to hypoxic water, but it also reduces the surface area available for ion exchange, so that ion regulation may at least in part be transferred to other organs, like the kidney or the gut. In the air-breathing Arapaima gigas, gill lamellae regress as development proceeds, and starting as a water-breathing embryo Arapaima turns into an obligate air-breathing fish with proceeding development, suggesting that ion regulation is shifted away from the gills as the fish grows. In Arapaima the kidney projects medially into the ABO and thus, probably a unique situation among fishes, is in close contact to the gas of the ABO. We therefore hypothesized that the kidney would be predestined to adopt an increased importance for ion homeostasis, because the elevated ATP turnover connected to ion transport can easily be met by aerobic metabolism based on the excellent oxygen supply directly from the ABO. We also hypothesized that in gill tissue the reduced ion regulatory activity should result in a reduced metabolic activity. High metabolic activity and exposure to high oxygen tensions are connected to the production of reactive oxygen species (ROS), therefore the tissues exposed to these conditions should have a high ROS defense capacity. Using in vitro studies, we assessed metabolic activity and ROS production of gill, kidney and ABO tissue, and determined the activity of ROS degrading enzymes in small (~ 5g, 2–3 weeks old) and larger (~ 670 g, 3–4 months old) A. gigas. Comparing the three tissues revealed that kidney tissue oxygen uptake by far exceeded the uptake measured in gill tissue or ABO. ROS production was particularly high in gill tissue, and all three tissues had a high capacity to degrade ROS. Gill tissue was characterized by high activities of enzymes involved in the glutathione pathway to degrade ROS. By contrast, the tissues of the ABO and in particular the kidney were characterized by high catalase activities, revealing different, tissue-specific strategies in ROS defense in this species. Overall the differences in the activity of cells taken from small and larger fish were not as pronounced as expected, while at the tissue level the metabolic activity of kidney cells by far exceeded the activity of ABO and gill cells.
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Pelster B, Wood CM, Braz-Mota S, Val AL. Gills and air-breathing organ in O 2 uptake, CO 2 excretion, N-waste excretion, and ionoregulation in small and large pirarucu (Arapaima gigas). J Comp Physiol B 2020; 190:569-583. [PMID: 32529591 DOI: 10.1007/s00360-020-01286-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 05/15/2020] [Accepted: 05/29/2020] [Indexed: 01/11/2023]
Abstract
In the pirarucu (Arapaima gigas), gill surface area and thus gas exchange capacity of the gills are reduced with proceeding development. It, therefore, is expected that A. gigas, starting as a water breather, progressively turns into an obligate air-breathing fish using an air-breathing organ (ABO) for gas exchange. We assessed the air-breathing activity, O2 and CO2 exchange into air and water, ammonia-N and urea-N excretion, ion flux rates, and activities of ion transport ATPases in large versus small pirarucu. We found that even very young A. gigas (4-6 g, 2-3 weeks post-hatch) with extensive gills are air-breathers (18.1 breaths*h-1) and cover most (63%) of their O2 requirements from the air whereas 600-700-g animals (about 3-4 months post-hatch), with reduced gills, obtain 75% of their O2 from the air (10.8 breaths*h-1). Accordingly, the reduction in gill surface area hardly affected O2 uptake, but development had a significant effect on aerial CO2 excretion, which was very low (3%) in small fish and increased to 12% in larger fish, yielding a hyper-allometric scaling coefficient (1.12) in contrast to 0.82-0.84 for aquatic and total CO2 excretion. Mass-specific ammonia excretion decreased in approximate proportion to mass-specific O2 consumption as the fish grew, but urea-N excretion dropped from 18% (at 4-6 g) to 8% (at 600-700 g) of total N-excretion; scaling coefficients for all these parameters were 0.70-0.80. Mass-specific sodium influx and efflux rates, as well as potassium net loss rates, departed from this pattern, being greater in larger fish; hyper-allometric scaling coefficients were > 1.0. Gill V-type H+ ATPase activities were greater than Na+, K+-ATPase activities, but levels were generally low and comparable in large and small fish, and similar activities were detected in the ABO. A. gigas is a carnivorous fish throughout its lifecycle, and, despite fasting, protein oxidation accounted for the major portion (61-82%) of aerobic metabolism in both large and small animals. ABO PO2 and PCO2 (measured in 600-700-g fish) were quite variable, and aerial hypoxia resulted in lower ABO PO2 values. Under normoxic conditions, a positive correlation between breath volume and ABP PO2 was detected, and on average with a single breath more than 50% of the ABO volume was exchanged. ABO PCO2 values were in the range of 1.95-3.89 kPa, close to previously recorded blood PCO2 levels. Aerial hypoxia (PO2 down to 12.65 kPa) did not increase either air-breathing frequency or breath volume.
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Affiliation(s)
- Bernd Pelster
- Institute of Zoology, University of Innsbruck, Innsbruck, Austria
- Center for Molecular Biosciences, University of Innsbruck, Innsbruck, Austria
| | - Chris M Wood
- Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
- Department of Biology, McMaster University, Hamilton, ON, L8S 4K1, Canada.
| | - Susana Braz-Mota
- Laboratory of Ecophysiology and Molecular Evolution, Brazilian National Institute for Research of the Amazon, Manaus, Brazil
| | - Adalberto L Val
- Laboratory of Ecophysiology and Molecular Evolution, Brazilian National Institute for Research of the Amazon, Manaus, Brazil
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Scadeng M, McKenzie C, He W, Bartsch H, Dubowitz DJ, Stec D, St. Leger J. Morphology of the Amazonian Teleost Genus Arapaima Using Advanced 3D Imaging. Front Physiol 2020; 11:260. [PMID: 32395105 PMCID: PMC7197331 DOI: 10.3389/fphys.2020.00260] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 03/06/2020] [Indexed: 11/13/2022] Open
Abstract
The arapaima is the largest of the extant air-breathing freshwater fishes. Their respiratory gas bladder is arguably the most striking of all the adaptations to living in the hypoxic waters of the Amazon basin, in which dissolved oxygen can reach 0 ppm (0 mg/l) at night. As obligatory air-breathers, arapaima have undergone extensive anatomical and physiological adaptations in almost every organ system. These changes were evaluated using magnetic resonance and computed tomography imaging, gross necropsy, and histology to create a comprehensive morphological assessment of this unique fish. Segmentation of advanced imaging data allowed for creation of anatomically accurate and quantitative 3D models of organs and their spatial relationships. The deflated gas bladder [1.96% body volume (BV)] runs the length of the coelomic cavity, and encompasses the kidneys (0.35% BV). It is compartmentalized by a highly vascularized webbing comprising of ediculae and inter-edicular septa lined with epithelium acting as a gas exchange surface analogous to a lung. Gills have reduced surface area, with severe blunting and broadening of the lamellae. The kidneys are not divided into separate regions, and have hematopoietic and excretory tissue interspersed throughout. The heart (0.21% BV) is encased in a thick layer of lipid rich tissue. Arapaima have an unusually large telencephalon (28.3% brain volume) for teleosts. The characteristics that allow arapaima to perfectly exploit their native environment also make them easy targets for overfishing. In addition, their habitat is at high risk from climate change and anthropogenic activities which are likely to result is fewer specimens living in the wild, or achieving their growth potential of up to 4.5 m in length.
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Affiliation(s)
- Miriam Scadeng
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
- Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
| | | | - Weston He
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
- NOVA Southeastern University, Fort Lauderdale, FL, United States
| | - Hauke Bartsch
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
- Mohn Medical Imaging and Visualization Centre, Haukeland University Hospital, Bergen, Norway
| | - David J. Dubowitz
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
- Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
| | - Dominik Stec
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
| | - Judy St. Leger
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
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Zaccone G, Cupello C, Capillo G, Kuciel M, Nascimento ALR, Gopesh A, Germanà GP, Spanò N, Guerrera MC, Aragona M, Crupi R, Icardo JM, Lauriano ER. Expression of Acetylcholine- and G protein coupled Muscarinic receptor in the Neuroepithelial cells (NECs) of the obligated air-breathing fish, Arapaima gigas (Arapaimatidae: Teleostei). ZOOLOGY 2020; 139:125755. [PMID: 32088527 DOI: 10.1016/j.zool.2020.125755] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 01/28/2020] [Accepted: 01/30/2020] [Indexed: 01/18/2023]
Abstract
The air-breathing specialization has evolved idependently in vertebrates, as many different organs can perfom gas exchange. The largest obligate air-breathing fish from South America Arapaima gigas breathe air using its gas bladder, and its dependence on air breathing increases during its growth. During its development, gill morphology shows a dramatic change, remodeling with a gradual reduction of gill lamellae during the transition from water breathing to air breathing . It has been suggested that in this species the gills remain the main site of O2 and CO2 sensing. Consistent with this, we demonstrate for the first time the occurrence of the neuroepithelial cells (NECs) in the glottis, and in the gill filament epithelia and their distal halves. These cells contain a broader spectrum of neurotransmitters (5-HT, acetylcholine, nNOS), G-protein subunits and the muscarininic receptors that are coupled to G proteins (G-protein coupled receptors). We report also for the first time the presence of G alpha proteins coupled with muscarinic receptors on the NECs, that are thought as receptors that initiate the cardiorespiratory reflexes in aquatic vertebrates. Based on the specific orientation in the epithelia and their closest vicinity to efferent vasculatures, the gill and glottal NECs of A. gigas could be regarded as potential O2 and CO2 sensing receptors. However, future studies are needed to ascertain the neurophysiological characterization of these cells.
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Affiliation(s)
- Giacomo Zaccone
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Polo Universitario dell'Annunziata, I-98168 Messina, Italy
| | - Camila Cupello
- Departamento de Zoologia, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier, 524, 20550-900, Rio de Janeiro, Brazil
| | - Gioele Capillo
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy.
| | - Michal Kuciel
- Poison Information Centre, Department of Toxicology and Environmental Disease, Faculty of Medicine, Jagellonian University, Kpernika 15, 30-501 Krakòw, Poland
| | - Ana L R Nascimento
- Departamento de Histologia e Embriologia, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, Avenida 28 de Setembro, 87, 20551-030, Rio de Janeiro, Brazil
| | - Anita Gopesh
- Department of Zoology, University of Allahabad, Allahabad 211002, U.P., India
| | - Germana Patrizia Germanà
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy
| | - Nunziacarla Spanò
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Polo Universitario dell'Annunziata, I-98168 Messina, Italy
| | - Maria Cristina Guerrera
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy
| | - Marialuisa Aragona
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy
| | - Rosalia Crupi
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy
| | - Jose Manuel Icardo
- Department of Anatomy and Cell Biology, Poligono de Cazona, Faculty of Medicine, University of Cantabria, Santander, Spain
| | - Eugenia Rita Lauriano
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale F. Stagno d'Alcontres 31, I-98166 Messina, Italy
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Burggren W, Bautista N. Invited review: Development of acid-base regulation in vertebrates. Comp Biochem Physiol A Mol Integr Physiol 2019; 236:110518. [DOI: 10.1016/j.cbpa.2019.06.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 06/24/2019] [Accepted: 06/25/2019] [Indexed: 12/26/2022]
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Effect of water pH and calcium on ion balance in five fish species of the Mekong Delta. Comp Biochem Physiol A Mol Integr Physiol 2019; 232:34-39. [DOI: 10.1016/j.cbpa.2019.02.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 02/27/2019] [Accepted: 02/28/2019] [Indexed: 11/21/2022]
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Thinh PV, Thanh Huong DT, Gam LTH, Damsgaard C, Phuong NT, Bayley M, Wang T. Renal acid excretion contributes to acid-base regulation during hypercapnia in air-exposed swamp eel ( Monopterus albus). ACTA ACUST UNITED AC 2019; 222:jeb.198259. [PMID: 30975740 DOI: 10.1242/jeb.198259] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 04/07/2019] [Indexed: 02/02/2023]
Abstract
The swamp eel (Monopterus albus) uses its buccal cavity to air breathe, while the gills are strongly reduced. It burrows into mud during the dry season, is highly tolerant of air exposure, and experiences severe hypoxia both in its natural habitat and in aquaculture. To study the ability of M. albus to compensate for respiratory acidosis, we implanted catheters to sample both arterial blood and urine during hypercapnia (4% CO2) in either water or air, or during whole-animal air exposure. These hypercapnic challenges caused an immediate reduction in arterial pH, followed by progressive compensation through a marked elevation of plasma HCO3 - over the course of 72 h. There was no appreciable rise in urinary acid excretion in fish exposed to hypercapnia in water, although urine pH was reduced and ammonia excretion did increase. In the air-exposed fish, however, hypercapnia was attended by a large elevation of ammonia in the urine and a large rise in titratable acid excretion. The time course of the increased renal acid excretion overlapped with the time period required to elevate plasma HCO3 -, and we estimate that the renal compensation contributed significantly to whole-body acid-base compensation.
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Affiliation(s)
- Phan Vinh Thinh
- College of Aquaculture and Fisheries, Can Tho University, Can Tho City, Vietnam.,Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
| | - Do Thi Thanh Huong
- College of Aquaculture and Fisheries, Can Tho University, Can Tho City, Vietnam
| | - Le Thi Hong Gam
- College of Aquaculture and Fisheries, Can Tho University, Can Tho City, Vietnam
| | - Christian Damsgaard
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
| | - Nguyen Thanh Phuong
- College of Aquaculture and Fisheries, Can Tho University, Can Tho City, Vietnam
| | - Mark Bayley
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
| | - Tobias Wang
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark .,Aarhus Institute of Advanced Studies, Aarhus University, 8000 Aarhus C, Denmark
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Pelster B, Wood CM. Ionoregulatory and oxidative stress issues associated with the evolution of air-breathing. Acta Histochem 2018; 120:667-679. [PMID: 30177382 DOI: 10.1016/j.acthis.2018.08.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Aquatic areas frequently face hypoxic conditions. In order to get sufficient oxygen to support aerobic metabolism, a number of freshwater fish resort to aerial respiration to supplement gill respiration especially in situations with reduced oxygen availability in the water. In many species a concomitant reduction in gill surface area or in gill perfusion reduces possible loss of aerially acquired oxygen to the water at the gills, but it also compromises the ion regulatory capacity of gill tissue. In consequence, the reduced gill contact area with water requires appropriate compensation to maintain ion and acid-base homeostasis, often with important ramifications for other organs. Associated modifications in the structure and function of the gills themselves, the skin, the gut, the kidney, and the physiology of water exchange and ion-linked acid-base regulation are discussed. In air-breathing fish, the gut may gain particular importance for the uptake of ions. In addition, tissues frequently exposed to environmental air encounter much higher oxygen partial pressures than typically observed in fish tissues. Physostomous fish using the swimbladder for aerial respiration, for example, will encounter aerial oxygen partial pressure at the swimbladder epithelium when frequently gulping air in hypoxic water. Hyperoxic conditions or rapid changes in oxygen partial pressures result in an increase in the production of reactive oxygen species (ROS). Accordingly, in air-breathing fish, strategies of ionoregulation may be greatly modified, and the ROS defense capacity of air-exposed tissues is improved.
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19
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Ramos CA, da Costa OTF, Duncan WLP, Fernandes MN. Morphofunctional description of mucous cells in the gills of the Arapaimidae Arapaima gigas
(Cuvier) during its development. Anat Histol Embryol 2018; 47:330-337. [DOI: 10.1111/ahe.12358] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 04/07/2018] [Indexed: 11/29/2022]
Affiliation(s)
- C. A. Ramos
- Department of Morphology; Federal University of Amazon; Coroado; Manaus Brazil
| | - O. T. F. da Costa
- Department of Morphology; Federal University of Amazon; Coroado; Manaus Brazil
| | - W. L. P. Duncan
- Department of Morphology; Federal University of Amazon; Coroado; Manaus Brazil
| | - M. N. Fernandes
- Physiological Sciences Department; Federal University of São Carlos; São Carlos Brazil
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Molecular and functional characterization of a fads2 orthologue in the Amazonian teleost, Arapaima gigas. Comp Biochem Physiol B Biochem Mol Biol 2017; 203:84-91. [DOI: 10.1016/j.cbpb.2016.09.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 09/08/2016] [Accepted: 09/27/2016] [Indexed: 02/08/2023]
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21
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Burggren WW, Bautista GM, Coop SC, Couturier GM, Delgadillo SP, García RM, González CAA. Developmental cardiorespiratory physiology of the air-breathing tropical gar, Atractosteus tropicus. Am J Physiol Regul Integr Comp Physiol 2016; 311:R689-R701. [PMID: 27465731 DOI: 10.1152/ajpregu.00022.2016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 07/08/2016] [Indexed: 12/18/2022]
Abstract
The physiological transition to aerial breathing in larval air-breathing fishes is poorly understood. We investigated gill ventilation frequency (fG), heart rate (fH), and air breathing frequency (fAB) as a function of development, activity, hypoxia, and temperature in embryos/larvae from day (D) 2.5 to D30 posthatch of the tropical gar, Atractosteus tropicus, an obligate air breather. Gill ventilation at 28°C began at approximately D2, peaking at ∼75 beats/min on D5, before declining to ∼55 beats/min at D30. Heart beat began ∼36-48 h postfertilization and ∼1 day before hatching. fH peaked between D3 and D10 at ∼140 beats/min, remaining at this level through D30. Air breathing started very early at D2.5 to D3.5 at 1-2 breaths/h, increasing to ∼30 breaths/h at D15 and D30. Forced activity at all stages resulted in a rapid but brief increase in both fG and fH, (but not fAB), indicating that even in these early larval stages, reflex control existed over both ventilation and circulation prior to its increasing importance in older fishes. Acute progressive hypoxia increased fG in D2.5-D10 larvae, but decreased fG in older larvae (≥D15), possibly to prevent branchial O2 loss into surrounding water. Temperature sensitivity of fG and fH measured at 20°C, 25°C, 28°C and 38°C was largely independent of development, with a Q10 between 20°C and 38°C of ∼2.4 and ∼1.5 for fG and fH, respectively. The rapid onset of air breathing, coupled with both respiratory and cardiovascular reflexes as early as D2.5, indicates that larval A. tropicus develops "in the fast lane."
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Affiliation(s)
- Warren W Burggren
- Developmental Integrative Biology Group, Department of Biology, University of North Texas, Denton, Texas; and
| | - Gil Martinez Bautista
- Laboratorio de Acuicultura Tropical, División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco, Mexico
| | - Susana Camarillo Coop
- Laboratorio de Acuicultura Tropical, División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco, Mexico
| | - Gabriel Márquez Couturier
- Laboratorio de Acuicultura Tropical, División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco, Mexico
| | - Salomón Páramo Delgadillo
- Laboratorio de Acuicultura Tropical, División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco, Mexico
| | - Rafael Martínez García
- Laboratorio de Acuicultura Tropical, División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco, Mexico
| | - Carlos Alfonso Alvarez González
- Laboratorio de Acuicultura Tropical, División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco, Mexico
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22
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Air breathing and aquatic gas exchange during hypoxia in armoured catfish. J Comp Physiol B 2016; 187:117-133. [DOI: 10.1007/s00360-016-1024-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 06/23/2016] [Accepted: 07/19/2016] [Indexed: 10/21/2022]
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Damsgaard C, Gam LTH, Dang DT, Van Thinh P, Huong DTT, Wang T, Bayley M. High capacity for extracellular acid-base regulation in the air-breathing fish Pangasianodon hypophthalmus. J Exp Biol 2015; 218:1290-4. [DOI: 10.1242/jeb.117671] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 03/09/2015] [Indexed: 02/03/2023]
Abstract
The evolution of accessory air-breathing structures is typically associated with reduction of the gills, although branchial ion transport remains pivotal for acid-base and ion-regulation. Therefore, air-breathing fishes are believed to have a low capacity for extracellular pH regulation during a respiratory acidosis. In the present study, we investigated acid-base regulation during hypercapnia in the air-breathing fish Pangasianodon hypophthalmus in normoxic and hypoxic water at 28-30°C. Contrary to previous studies, we show that this air-breathing fish has a pronounced ability to regulate pHe during hypercapnia, with complete metabolic compensation of extracellular pH within 72 h of exposure to hypoxic hypercapnia with CO2 levels above 34 mmHg. The high capacity for pHe regulation relies on a pronounced ability to increase [HCO3−]plasma. Our study illustrates the diversity in the physiology of air-breathing fishes, such that generalizations across phylogenies may be difficult.
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Affiliation(s)
| | - Le Thi Hong Gam
- College of Aquaculture and Fisheries, Can Tho University, Can Tho City, Vietnam
| | - Diem Tuong Dang
- College of Aquaculture and Fisheries, Can Tho University, Can Tho City, Vietnam
| | - Phan Van Thinh
- College of Aquaculture and Fisheries, Can Tho University, Can Tho City, Vietnam
| | - Do Thi Thanh Huong
- College of Aquaculture and Fisheries, Can Tho University, Can Tho City, Vietnam
| | - Tobias Wang
- Zoophysiology, Institute for Bioscience, Aarhus University, Aarhus, Denmark
| | - Mark Bayley
- Zoophysiology, Institute for Bioscience, Aarhus University, Aarhus, Denmark
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Shartau RB, Brauner CJ. Acid-base and ion balance in fishes with bimodal respiration. JOURNAL OF FISH BIOLOGY 2014; 84:682-704. [PMID: 24502749 DOI: 10.1111/jfb.12310] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The evolution of air breathing during the Devonian provided early fishes with bimodal respiration with a stable O2 supply from air. This was, however, probably associated with challenges and trade-offs in terms of acid-base balance and ionoregulation due to reduced gill:water interaction and changes in gill morphology associated with air breathing. While many aspects of acid-base and ionoregulation in air-breathing fishes are similar to water breathers, the specific cellular and molecular mechanisms involved remain largely unstudied. In general, reduced ionic permeability appears to be an important adaptation in the few bimodal fishes investigated but it is not known if this is a general characteristic. The kidney appears to play an important role in minimizing ion loss to the freshwater environment in the few species investigated, and while ion uptake across the gut is probably important, it has been largely unexplored. In general, air breathing in facultative air-breathing fishes is associated with an acid-base disturbance, resulting in an increased partial pressure of arterial CO2 and a reduction in extracellular pH (pHE ); however, several fishes appear to be capable of tightly regulating tissue intracellular pH (pHI ), despite a large sustained reduction in pHE , a trait termed preferential pHI regulation. Further studies are needed to determine whether preferential pHI regulation is a general trait among bimodal fishes and if this confers reduced sensitivity to acid-base disturbances, including those induced by hypercarbia, exhaustive exercise and hypoxia or anoxia. Additionally, elucidating the cellular and molecular mechanisms may yield insight into whether preferential pHI regulation is a trait ultimately associated with the early evolution of air breathing in vertebrates.
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Affiliation(s)
- R B Shartau
- Department of Zoology, University of British Columbia, 6270 University Blvd., Vancouver, BC, V6T 1Z4 Canada
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Ramos CA, Fernandes MN, da Costa OTF, Duncan WP. Implications for osmorespiratory compromise by anatomical remodeling in the gills of Arapaima gigas. Anat Rec (Hoboken) 2013; 296:1664-75. [PMID: 23956000 DOI: 10.1002/ar.22758] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Accepted: 05/22/2013] [Indexed: 11/05/2022]
Abstract
The gill structure of the Amazonian fish Arapaima gigas, an obligatory air breather, was investigated during its transition from water breathing to the obligatory air breathing modes of respiration. The gill structure of A. gigas larvae is similar to that of most teleost fish; however, the morphology of the gills changes as the fish grow. The main morphological changes in the gill structure of a growing fish include the following: (1) intense cell proliferation in the filaments and lamellae, resulting in increasing epithelial thickness and decreasing interlamellar distance; (2) pillar cell system atrophy, which reduces the blood circulation through the lamellae; (3) the generation of long cytoplasmic processes from the epithelial cells into the intercellular space, resulting in continuous and sinuous paracellular channels between the epithelial cells of the filament and lamella that may be involved in gas, ion, and nutrient transport to epithelial cells; and (4) intense mitochondria-rich cell (MRC) proliferation in the lamellar epithelium. All of these morphological changes in the gills contribute to a low increase of the respiratory surface area for gas exchange and an increase in the water-blood diffusion distance increasing their dependence on air-breathing as fish developed. The increased proliferation of MRCs may contribute to increased ion uptake, which favors the regulation of ion content and pH equilibrium.
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Affiliation(s)
- Cleverson Agner Ramos
- Departamento de Ciências Fisiológicas, Universidade Federal de São Carlos, Rodovia Washington Luís, KM 235 Caixa Postal 676, São Carlos, SP, Brasil; Departamento de Morfologia, Universidade Federal do Amazonas, Avenida General, Rodrigo Octávio Jordão Ramos, 3000. 69.077-000, Manaus, Amazonas, Brazil
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Morphometric partitioning of the respiratory surface area and diffusion capacity of the gills and swim bladder in juvenile Amazonian air-breathing fish, Arapaima gigas. Micron 2012; 43:961-70. [DOI: 10.1016/j.micron.2012.03.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 03/16/2012] [Accepted: 03/23/2012] [Indexed: 11/19/2022]
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Lefevre S, Jensen FB, Huong DTT, Wang T, Phuong NT, Bayley M. Haematological and ion regulatory effects of nitrite in the air-breathing snakehead fish Channa striata. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2012; 118-119:48-53. [PMID: 22516674 DOI: 10.1016/j.aquatox.2012.03.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Revised: 03/16/2012] [Accepted: 03/20/2012] [Indexed: 05/31/2023]
Abstract
The tolerance and effects of nitrite on ion balance and haematology were investigated in the striped snakehead, Channa striata Bloch 1793, which is an air-breathing fish with reduced gills of importance for aquaculture in South East Asia. C. striata was nitrite tolerant with a 96 h LC50 of 4.7 mM. Effects of sub-lethal exposures to nitrite (0mM, 1.4mM, and 3.0mM) were determined during a 7-day exposure period. Plasma nitrite increased, but the internal concentration remained well below ambient levels. Extracellular nitrate rose by several mM, indicating that a large proportion of the nitrite taken up was converted to nitrate. Nitrite reacted with erythrocyte haemoglobin (Hb) causing methaemoglobin (metHb) to increase to 30% and nitrosylhaemoglobin (HbNO) to increase to 10% of total Hb. Both metHb and HbNO stabilised after 4 days, and functional Hb levels accordingly never fell below 60% of total Hb. Haematocrit and total Hb were unaffected by nitrite. Although the effects of nitrite exposure seemed minor in terms of plasma nitrite and metHb increases, ion balance was strongly affected. In the high exposure group, total osmolality decreased from 320 mOsm to 260 mOsm, and plasma sodium from 150 mM to 120 mM, while plasma chloride fell from 105 mM to 60mM and plasma bicarbonate rose from 12 mM in controls to 20mM in exposed fish. The extreme changes in ion balance in C. striata are different from the response reported in other fish, and further studies are needed to investigate the mechanism behind the observed changes in regulation.
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Affiliation(s)
- Sjannie Lefevre
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark.
| | - Frank B Jensen
- Institute of Biology, University of Southern Denmark, Odense, Denmark
| | - Do T T Huong
- College of Aquaculture and Fisheries, Can Tho University, Can Tho City, Viet Nam
| | - Tobias Wang
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Nguyen T Phuong
- College of Aquaculture and Fisheries, Can Tho University, Can Tho City, Viet Nam
| | - Mark Bayley
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
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Brauner CJ, Rombough PJ. Ontogeny and paleophysiology of the gill: new insights from larval and air-breathing fish. Respir Physiol Neurobiol 2012; 184:293-300. [PMID: 22884973 DOI: 10.1016/j.resp.2012.07.011] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 07/13/2012] [Accepted: 07/17/2012] [Indexed: 11/17/2022]
Abstract
There are large changes in gill function during development associated with ionoregulation and gas exchange in both larval and air-breathing fish. Physiological studies of larvae indicate that, contrary to accepted dogma but consistent with morphology, the initial function of the gill is primarily ionoregulatory and only secondarily respiratory. In air-breathing fish, as the gill becomes progressively less important in terms of O(2) uptake with expansion of the air-breathing organ, it retains its roles in CO(2) excretion, ion exchange and acid-base balance. The observation that gill morphology and function is strongly influenced by ionoregulatory needs in both larval and air-breathing fish may have evolutionary implications. In particular, it suggests that the inability of the skin to maintain ion and acid-base balance as protovertebrates increased in size and became more active may have been more important in driving gill development than O(2) insufficiency.
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Affiliation(s)
- Colin J Brauner
- Department of Zoology, University of British Columbia, Vancouver, BC V6 T 1Z4, Canada.
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29
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Brauner CJ, Gonzalez RJ, Wilson JM. Extreme Environments: Hypersaline, Alkaline, and Ion-Poor Waters. FISH PHYSIOLOGY 2012. [DOI: 10.1016/b978-0-12-396951-4.00009-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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30
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Gonzales TT, Katoh M, Ghaffar MA, Ishimatsu A. Gross and fine anatomy of the respiratory vasculature of the mudskipper, Periophthalmodon schlosseri (Gobiidae: Oxudercinae). J Morphol 2011; 272:629-40. [DOI: 10.1002/jmor.10944] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2010] [Revised: 09/30/2010] [Accepted: 11/06/2010] [Indexed: 11/11/2022]
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