Next Article in Journal
Structure of Rhodolith Beds and Surrounding Habitats at the Doce River Shelf (Brazil)
Previous Article in Journal
Livelihood, Food and Nutrition Security in Southern Africa: What Role Do Indigenous Cattle Genetic Resources Play?
Previous Article in Special Issue
Species Composition and Distribution of Jellyfish in a Seasonally Hypoxic Estuary, Hood Canal, Washington
Open AccessArticle

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

Gulf Coast Research Laboratory, Division of Coastal Sciences, School of Ocean Science and Engineering, University of Southern Mississippi, Ocean Springs, MS 39564, USA
*
Author to whom correspondence should be addressed.
Diversity 2020, 12(2), 73; https://doi.org/10.3390/d12020073
Received: 21 January 2020 / Revised: 5 February 2020 / Accepted: 7 February 2020 / Published: 12 February 2020
(This article belongs to the Special Issue The Effects of Hypoxia on Marine Food Webs and Ecosystems)
Understanding the capacity of estuarine organisms to acclimate to stressful conditions provides insights into how communities cope within fluctuating environments. The opportunistic spionid polychaete, Streblospio gynobranchiata 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 °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 °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 S. gynobranchiata 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.
Keywords: respiration; hypoxia; tolerant polychaete; oxyregulation; oxygen debt respiration; hypoxia; tolerant polychaete; oxyregulation; oxygen debt
MDPI and ACS Style

Bennett, A.D.; Rakocinski, C.F. Respiration by the Opportunistic Spionid Polychaete Streblospio gynobranchiata during Adjustment to and Recovery from Moderate Hypoxia. Diversity 2020, 12, 73.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop