caa a22 4500 605514488 CHVBK 20210128100704.0 cr unu---uuuuu 210128e20150701xx s 000 0 eng 10.1007/s00360-015-0902-z doi (NATIONALLICENCE)springer-10.1007/s00360-015-0902-z Osmoregulatory adaptations of freshwater air-breathing snakehead fish ( Channa striata ) after exposure to brackish water [Elektronische Daten] [La-iad Nakkrasae, Khanitha Wisetdee, Narattaphol Charoenphandhu] NaCl-rich rock salt dissolved in natural water source leads to salinity fluctuation that profoundly affects freshwater ecosystem and aquatic fauna. The snakehead (Channa striata) can live in saline water, but the osmoregulatory mechanisms underlying this ability remain unclear. Herein, we found that exposure to salinities ≥10‰ NaCl markedly elevated plasma cortisol and glucose levels, and caused muscle dehydration. In a study of time-dependent response after being transferred from fresh water (0‰ NaCl, FW) to salt-dissolved brackish water (10‰ NaCl, SW), FW-SW, cortisol increased rapidly along with elevations of plasma glucose and lactate. Interestingly, plasma cortisol returned to baseline after prolonged exposure, followed by a second peak that probably enhanced the branchial Na+/K+-ATPase activity. Under SW-FW condition, Na+/K+-ATPase activity was not altered as compared to SW-adapted fish. In conclusion, salinity change, especially FW-SW, induced a stress response and hence cortisol release in C. striata, which might increase plasma glucose and lactate to energize the branchial Na+/K+-ATPase. Springer-Verlag Berlin Heidelberg, 2015 Cortisol nationallicence Na+/K+-ATPase activity nationallicence Osmoregulation nationallicence Salinity fluctuation nationallicence Snakehead nationallicence Nakkrasae La-iad Department of Biology, Faculty of Science, Khon Kaen University, 40002, Khon Kaen, Thailand aut Wisetdee Khanitha Department of Biology, Faculty of Science, Khon Kaen University, 40002, Khon Kaen, Thailand aut Charoenphandhu Narattaphol Department of Physiology, Faculty of Science, Mahidol University, 10400, Bangkok, Thailand aut Journal of Comparative Physiology B Springer Berlin Heidelberg 185/5(2015-07-01), 527-537 0174-1578 185:5<527 2015 185 360 https://doi.org/10.1007/s00360-015-0902-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00360-015-0902-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Nakkrasae La-iad Department of Biology, Faculty of Science, Khon Kaen University, 40002, Khon Kaen, Thailand aut NATIONALLICENCE 700 1- Wisetdee Khanitha Department of Biology, Faculty of Science, Khon Kaen University, 40002, Khon Kaen, Thailand aut NATIONALLICENCE 700 1- Charoenphandhu Narattaphol Department of Physiology, Faculty of Science, Mahidol University, 10400, Bangkok, Thailand aut NATIONALLICENCE 773 0- Journal of Comparative Physiology B Springer Berlin Heidelberg 185/5(2015-07-01), 527-537 0174-1578 185:5<527 2015 185 360