Respiration by the Opportunistic Spionid Polychaete <i>Streblospio gynobranchiata</i> during Adjustment to and Recovery from Moderate Hypoxia

Understanding the capacity of estuarine organisms to acclimate to stressful conditions provides insights into how communities cope within fluctuating environments. The opportunistic spionid polychaete, <i>Streblospio gynobranchiata</i> Rice and Levin, 1998, regularly experiences intermit...

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Main Authors: Alyssa D. Bennett, Chet F. Rakocinski
Format: Article
Language:English
Published: MDPI AG 2020-02-01
Series:Diversity
Subjects:
Online Access:https://www.mdpi.com/1424-2818/12/2/73
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author Alyssa D. Bennett
Chet F. Rakocinski
author_facet Alyssa D. Bennett
Chet F. Rakocinski
author_sort Alyssa D. Bennett
collection DOAJ
description Understanding the capacity of estuarine organisms to acclimate to stressful conditions provides insights into how communities cope within fluctuating environments. The opportunistic spionid polychaete, <i>Streblospio gynobranchiata</i> Rice and Levin, 1998, regularly experiences intermittent moderate hypoxia within shallow sedimentary habitats. To better understand fine-scale adjustments by this opportunistic species to short-term moderate hypoxia, the aerobic respiration response of three size classes was examined over a 12 h period and after 24 h of exposure to moderate hypoxia (i.e., 20% air saturation) at 25 &#176;C. In addition, the capacity to resume standard respiration was examined over a 12 h period following a 24 h period of exposure to moderate hypoxia. Mass-specific respiration varied with body size during both exposure and recovery from hypoxia. Small worms switched from an oxyregulating to an oxyconforming strategy within 6 h of exposure to moderate hypoxia at 25 &#176;C. After 24 h of hypoxia exposure, small worms hypo-regulated at 81% of the preceding 24 h normoxic reference level. By contrast, medium and large worms hyper-regulated during the first 12 h exposure period, but hypo-regulated at 70% and 79% of the preceding 24 h normoxic reference levels after 24 h of hypoxia exposure. Fluctuations in respiration levels during the recovery period revealed a temporal recovery pattern implying cycling energetic processes. The recovery pattern also indicated some respiration overshoot to compensate for oxygen debt. The timing of the cycling recovery pattern also differed with body size. The ability of <i>S. gynobranchiata</i> to dynamically adjust its metabolic response to low oxygen stress underscores the ecologically important role of tolerant organisms within estuarine benthic habitats subject to recurrent diel or intermittent hypoxia.
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spelling doaj.art-251e0d56288b4d75b4d4717c3349bd552022-12-22T04:01:25ZengMDPI AGDiversity1424-28182020-02-011227310.3390/d12020073d12020073Respiration by the Opportunistic Spionid Polychaete <i>Streblospio gynobranchiata</i> during Adjustment to and Recovery from Moderate HypoxiaAlyssa D. Bennett0Chet F. Rakocinski1Gulf Coast Research Laboratory, Division of Coastal Sciences, School of Ocean Science and Engineering, University of Southern Mississippi, Ocean Springs, MS 39564, USAGulf Coast Research Laboratory, Division of Coastal Sciences, School of Ocean Science and Engineering, University of Southern Mississippi, Ocean Springs, MS 39564, USAUnderstanding the capacity of estuarine organisms to acclimate to stressful conditions provides insights into how communities cope within fluctuating environments. The opportunistic spionid polychaete, <i>Streblospio gynobranchiata</i> Rice and Levin, 1998, regularly experiences intermittent moderate hypoxia within shallow sedimentary habitats. To better understand fine-scale adjustments by this opportunistic species to short-term moderate hypoxia, the aerobic respiration response of three size classes was examined over a 12 h period and after 24 h of exposure to moderate hypoxia (i.e., 20% air saturation) at 25 &#176;C. In addition, the capacity to resume standard respiration was examined over a 12 h period following a 24 h period of exposure to moderate hypoxia. Mass-specific respiration varied with body size during both exposure and recovery from hypoxia. Small worms switched from an oxyregulating to an oxyconforming strategy within 6 h of exposure to moderate hypoxia at 25 &#176;C. After 24 h of hypoxia exposure, small worms hypo-regulated at 81% of the preceding 24 h normoxic reference level. By contrast, medium and large worms hyper-regulated during the first 12 h exposure period, but hypo-regulated at 70% and 79% of the preceding 24 h normoxic reference levels after 24 h of hypoxia exposure. Fluctuations in respiration levels during the recovery period revealed a temporal recovery pattern implying cycling energetic processes. The recovery pattern also indicated some respiration overshoot to compensate for oxygen debt. The timing of the cycling recovery pattern also differed with body size. The ability of <i>S. gynobranchiata</i> to dynamically adjust its metabolic response to low oxygen stress underscores the ecologically important role of tolerant organisms within estuarine benthic habitats subject to recurrent diel or intermittent hypoxia.https://www.mdpi.com/1424-2818/12/2/73respirationhypoxiatolerant polychaeteoxyregulationoxygen debt
spellingShingle Alyssa D. Bennett
Chet F. Rakocinski
Respiration by the Opportunistic Spionid Polychaete <i>Streblospio gynobranchiata</i> during Adjustment to and Recovery from Moderate Hypoxia
Diversity
respiration
hypoxia
tolerant polychaete
oxyregulation
oxygen debt
title Respiration by the Opportunistic Spionid Polychaete <i>Streblospio gynobranchiata</i> during Adjustment to and Recovery from Moderate Hypoxia
title_full Respiration by the Opportunistic Spionid Polychaete <i>Streblospio gynobranchiata</i> during Adjustment to and Recovery from Moderate Hypoxia
title_fullStr Respiration by the Opportunistic Spionid Polychaete <i>Streblospio gynobranchiata</i> during Adjustment to and Recovery from Moderate Hypoxia
title_full_unstemmed Respiration by the Opportunistic Spionid Polychaete <i>Streblospio gynobranchiata</i> during Adjustment to and Recovery from Moderate Hypoxia
title_short Respiration by the Opportunistic Spionid Polychaete <i>Streblospio gynobranchiata</i> during Adjustment to and Recovery from Moderate Hypoxia
title_sort respiration by the opportunistic spionid polychaete i streblospio gynobranchiata i during adjustment to and recovery from moderate hypoxia
topic respiration
hypoxia
tolerant polychaete
oxyregulation
oxygen debt
url https://www.mdpi.com/1424-2818/12/2/73
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