Differing modes of growth performance induced by hypoxia and effects on oxidative defense and glycolysis metabolism in two marine Brachionus rotifer species

Autor: Chengyan Han, Atsushi Hagiwara
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Aquaculture. 567:739286
ISSN: 0044-8486
Popis: Hypoxia is often a concern in closed, recirculating aquaculture facilities. Here, we examined the effects of hypoxia (0.3–1.0 mg O2/L; two days of continuous exposure) on growth and metabolism in two marine rotifers, Brachionus plicatilis and Brachionus rotundiformis, having differing sizes and environmental acclimation abilities. The obtained results revealed that the super-small (SS)-type rotifer B. rotundiformis possesses higher tolerance to hypoxia during reproduction than the large (L)-type B. plicatilis. Exposure to hypoxia significantly inhibited the growth of B. plicatilis, whereas it had no influence on B. rotundiformis. While adaptive strategies, such as smaller body size and enhanced swimming speed, were detected in B. rotundiformis. To identify the underlying mechanisms of the phenomena, the activity of key biomarkers and enzymes involved in oxidative defense and glycolysis (energy) was examined. In B. plicatilis, although the level of antioxidants increased, hypoxia still induced the production of high levels of reactive oxygen species (ROS) and hypoxia-inducible factors (single-minded homolog 1 and aryl hydrocarbon receptor nuclear translocator). However, in B. rotundiformis, enhanced defensive responses (increment of manganese superoxide dismutase and glutathione S-transferase levels) successfully maintained the balance of ROS during hypoxia. Regarding energy metabolism, the expression of six key biomarkers involved in the glycolytic pathway was all significantly upregulated in B. plicatilis. Both B. plicatilis and B. rotundiformis increased ATP production, by 1.9- and 1.2-fold, respectively. Unlike B. plicatilis, B. rotundiformis may have used the produced ATP to swim faster and maintain reproductive homeostasis. The difference in resistance and growth/molecular responses to hypoxic exposure between B. plicatilis and B. rotundiformis may be attributed to their disparate mass-specific metabolic rates and habitat-evolutionary adaptations. The greater tolerance for hypoxia is beneficial to the rapid and high-density cultivation of B. rotundiformis in aquaculture facilities.
Aquaculture, 567, art. no. 739286; 2023
Databáze: OpenAIRE
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