The effects of transfer from steady-state to tidally-changing salinities on plasma and branchial osmoregulatory variables in adult Mozambique tilapia.

Autor: Pavlosky KK; Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI 96744, USA; Department of Molecular Biosciences and Bioengineering, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA., Yamaguchi Y; Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI 96744, USA; Faculty of Life and Environmental Science, Shimane University, Matsue, Shimane 690-8504, Japan., Lerner DT; Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI 96744, USA; University of Hawai'i Sea Grant College Program, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA., Seale AP; Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI 96744, USA; Department of Human Nutrition, Food and Animal Sciences, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA. Electronic address: seale@hawaii.edu.
Jazyk: angličtina
Zdroj: Comparative biochemistry and physiology. Part A, Molecular & integrative physiology [Comp Biochem Physiol A Mol Integr Physiol] 2019 Jan; Vol. 227, pp. 134-145. Date of Electronic Publication: 2018 Oct 11.
DOI: 10.1016/j.cbpa.2018.10.005
Abstrakt: The Mozambique tilapia, Oreochromis mossambicus, is a teleost fish native to estuarine waters that vary in salinity between fresh water (FW) and seawater (SW). The neuroendocrine system plays a key role in salinity acclimation by directing ion uptake and extrusion in osmoregulatory tissues such as gill. While most studies with O. mossambicus have focused on acclimation to steady-state salinities, less is known about the ability of adult fish to acclimate to dynamically-changing salinities. Plasma osmolality, prolactin (PRL) levels, and branchial gene expression of PRL receptors (PRLR1 and PRLR2), Na + /Cl - and Na + /K + /2Cl - co-transporters (NCC and NKCC), Na + /K + -ATPase (NKAα1a and NKAα1b), cystic fibrosis transmembrane conductance regulator (CFTR), and aquaporin 3 (AQP3) were measured in fish reared in FW and SW steady-state salinities, in a tidal regimen (TR) where salinities changed between FW and SW every six hours, and in fish transferred from FW or SW to TR. Regardless of rearing regimen, plasma osmolality was higher in fish in SW than in FW fish, while plasma PRL was lower in fish in SW. Furthermore, branchial gene expression of effectors of ion transport in TR fish showed greater similarity to those in steady-state SW fish than in FW fish. By seven days of transfer from steady-state FW or SW to TR, plasma osmolality, plasma PRL and branchial expression of effectors of ion transport were similar to those of fish reared in TR since larval stages. These findings demonstrate the ability of adult tilapia reared in steady-state salinities to successfully acclimate to dynamically-changing salinities. Moreover, the present findings suggest that early exposure to salinity changes does not significantly improve survivability in future challenge with dynamically-changing salinities.
(Copyright © 2018 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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