Osmoregulatory adaptations of freshwater air-breathing snakehead fish (Channa striata) after exposure to brackish water

High-density lipoprotein remodeling affects the osmotic properties of plasma in goldfish under critical salinity

To investigate the stress response and physiological adaptations of goldfish (Carassius auratus) to critical salinity (CS) waters, we analyzed high-density lipoprotein (HDL) stoichiometry, stress markers (cortisol, glucose), and plasma osmotic properties (Na+ , osmolality, water content) using ichthyology, biochemistry, and proteomics approaches. After 21 days of exposure to CS, plasma concentrations of cortisol, glucose, and Na+ increased, indicating stress. Total plasma osmolality (Osmtotal ) and osmolality generated by inorganic (Osminorg ) and organic osmolytes (Osmorg ) also increased, the latter by ~2%. We associated the increase of Osmorg with (1) increased metabolite concentration (glucose), (2) dissociation of HDL particles resulting in increased HDL number per unit plasma volume (~1.5-2-fold) and (3) increased HDL osmotic activity. HDL remodeling may be the reason for the redistribution of bound and free water in plasma, which may contribute to water retention in plasma and, at the same time, to hemodynamic disturbances under CS conditions. The study's findings suggest that HDL remodeling is an important mechanism for maintaining osmotic homeostasis in fish, which is consistent with current capillary exchange models in vertebrates.

Toxic Heavy Metals and Their Risk Assessment of Exposure in Selected Freshwater and Marine Fish in Thailand

This study identified the levels of arsenic, cadmium, mercury, and lead in 15 species of commonly consumed fish in Thailand (7 freshwater species, 8 marine species), as well as the risk of these toxic elements for consumers. Inductively coupled plasma mass spectrometry (ICP-MS-MS) was used to identify toxic elements, while an exposure assessment was conducted by applying consumption amounts from the national food consumption survey to the toxic element contents in the fish samples. The results showed that the fish contained arsenic ranging from less than the limit of detection (LOD) to 8.51 mg/kg fresh weight (FW), cadmium ranging from the LOD to 0.04 mg/kg FW, and mercury ranging from the limit of quantitation (LOQ) to 0.38 mg/kg FW. Lead was found in small amounts ( Collapse

Key Words

• exposure
• fish
• risk assessment
• toxic elements

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Grants

• grant year 2021 Mahidol University

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Affiliation(s)

Prasit Sirisangarunroj Master of Science Program in Nutrition, Faculty of Medicine Ramathibodi Hospital and Institute of Nutrition, Mahidol University, Nakhon Pathom 73170, Thailand;
Nuntawat Monboonpitak Institute of Nutrition, Mahidol University, Salaya, Phutthamonthon, Nakhon Pathom 73170, Thailand; (N.M.); (P.S.)
Weeraya Karnpanit School of Science, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia;
Piyanut Sridonpai Institute of Nutrition, Mahidol University, Salaya, Phutthamonthon, Nakhon Pathom 73170, Thailand; (N.M.); (P.S.)
Alongkote Singhato Nutrition and Dietetics Division, Faculty of Allied Health Sciences, Burapha University, Chonburi 20131, Thailand;
Nunnapus Laitip Chemical Metrology and Biometry Department, National Institute of Metrology (Thailand), Pathum Thani 12120, Thailand; (N.L.); (N.O.); (C.Y.)
Nattikarn Ornthai Chemical Metrology and Biometry Department, National Institute of Metrology (Thailand), Pathum Thani 12120, Thailand; (N.L.); (N.O.); (C.Y.)
Charun Yafa Chemical Metrology and Biometry Department, National Institute of Metrology (Thailand), Pathum Thani 12120, Thailand; (N.L.); (N.O.); (C.Y.)
Kunchit Judprasong Institute of Nutrition, Mahidol University, Salaya, Phutthamonthon, Nakhon Pathom 73170, Thailand; (N.M.); (P.S.)

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Physiological responses to swimming fatigue in juvenile largemouth bronze gudgeon Coreius guichenoti

Stepped velocity tests were conducted on juvenile largemouth bronze gudgeon Coreius guichenoti in a swim tunnel respirometer, and oxygen consumption increased with swimming speed to fatigue and then decreased during recovery. Serum levels of total protein, glucose and triglycerides initially decreased, increased at fatigue and then decreased during recovery. Levels stabilized after 120 min, corresponding to the time necessary to recover from fatigue.