scholarly journals A review on the activity of Na+/K+-ATPase in branchial ionocytes and its role in salinity adaptation among diadromous species

2020 ◽  
Vol 6 (2) ◽  
pp. 201-211
Author(s):  
Jumah Yashier Upling
Keyword(s):  
Salinity Adaptation ◽  
Diadromous Species

Interactive effects of salinity on metabolic rate, activity, growth and osmoregulation in the euryhaline milkfish (Chanos chanos)

1998 ◽  
Vol 201 (24) ◽  
pp. 3355-3366
Author(s):  
C Swanson
Keyword(s):  
Metabolic Rate ◽  
High Salinity ◽  
Swimming Performance ◽  
Interactive Effects ◽  
Routine Activity ◽  
Swimming Velocity ◽  
Activity Levels ◽  
Salinity Adaptation ◽  
Chanos Chanos ◽  
Wide Range

The euryhaline milkfish (Chanos chanos) is an excellent subject for studies of the physiological and behavioral processes involved in salinity adaptation. In this study, energy partitioning for metabolism, activity and growth, maximal activity performance and blood osmotic concentrations were assessed at two activity levels in juvenile milkfish fed equal rations and maintained at a relatively constant temperature (262 C) and at salinities(15, 35 and 55 ?) that represented a wide range of osmoregulatory challenges. Changes in the measured parameters were not consistently related to the magnitude of the trans-integumentary osmotic gradients. Routine oxygen consumption rates were high in 35 ? salinity (mean 1 s.e.m. 1678 mg O2 kg-1 h-1) and comparably low in 15 and 55 ? salinity (1336 and 1273 mg O2 kg-1 h-1, respectively). Routine activity levels (relative swimming velocity) were highest in 35 ? salinity (0. 960.04 L s-1), where L is standard length, intermediate in 15 ? salinity (0.770.03 L s-1) and lowest in 55 ? salinity (0.670.03 L s-1). Growth was significantly higher in 55 ? salinity (3.40.2 % increase in wet body mass per day) than in 35 ?salinity (2.40.2 % increase per day) and intermediate in 15 ? salinity(2.90.5 % increase per day). Maximum swimming velocities decreased with increases in salinity, from 9.90.7 L s-1 in 15 ? salinity to 6.60. 5 L s-1 in 55 ? salinity. Sustained swimming activity above routine levels for 2 h resulted in an increase in blood osmotic concentrations in milkfish in 55 ?salinity, but osmoregulation was re-established during the second 2 h of activity. Thus, patterns of variation in metabolic rate and growth were largely parallel to variations in routine activity although, comparing 15 and 55 ? salinity, elevated maintenance costs for osmoregulation at the high salinity were detectable. Reduced osmoregulatory abilities and reductions in maximal swimming performance suggest that high salinity may constrain activity. The results demonstrate that investigations of salinity adaptation in euryhaline fishes should take into account the interactive effects of salinity on physiology and behavior.

Transmembrane Activity Gradients of K and cl in the Muscle Fibres of Osmoconforming Marine Decapod Crustaceans

1978 ◽  
Vol 72 (1) ◽  
pp. 127-140
Author(s):  
ROBERT W. FREEL
Keyword(s):  
Sea Water ◽  
Membrane Potentials ◽  
Resting Potential ◽  
Muscle Fibres ◽  
Salinity Adaptation ◽  
Decapod Crustaceans ◽  
Marine Crustaceans ◽  
Equilibrium Distributions

1. The resting membrane potentials (Em) and the transmembrane activity gradients for K and Cl were measured in the muscle fibres of osmoconforming (Callianassa and Cancer) and weakly osmoregulating (Pachygrapsus) marine crustaceans acclimated to various osmotic conditions. 2. The muscle membranes of sea water acclimated crabs behave as good K electrodes. However, a slight contribution of Na to the resting potential was demonstrated in all species. The ratio PNa/PK was about 0.01. Equilibrium potentials (measured with ion-selective microelectrodes) for Cl were equal to Em, while EK was always more negative than Em as a result of the slight Na contribution. 3. Acclimation to dilute or concentrated sea water had little effect on the K electrode properties or Na permeabilities of these fibres. The muscle fibres were depolarized in crabs acclimated to concentrated sea water and were hyperpolarized in crabs adapted to dilute sea water. These changes resulted solely from alterations in (aK)i/ (aK)O which were in turn brought about by changes in cellular and haemolymph hydration. 4. Since the Na contribution to Em was so small in all conditions, it was concluded that the distributions of K and Cl are best considered in terms of Donnan equilibria, and that the cellular K and Cl adjustments observed during salinity adaptation reflect the passive re-establishment of new equilibrium distributions for these ions.

Characterization of the Low-Salinity Stress in Vibrio vulnificus

2008 ◽  
Vol 71 (2) ◽  
pp. 416-419 ◽  
Author(s):  
HIN-CHUNG WONG ◽  
SHU-HUI LIU
Keyword(s):  
Salinity Stress ◽  
Food Processing ◽  
Vibrio Vulnificus ◽  
Exponential Phase ◽  
Salinity Adaptation ◽  
Significant Protection ◽  
Low Salinity ◽  
Short Period ◽  
Nonculturable State

Vibrio vulnificus is a marine pathogenic bacterium commonly found in seawater or seafood. This organism encounters low-salinity stress in its natural environment and during food processing. This study was designed to investigate the response of V. vulnificus YJ03 to lethal low salinity (0.04% NaCl) and its adaptation to sublethal salinity (0.12% NaCl with 20 amino acids added). A short period in the nonculturable state was induced by lethal low-salinity stress followed by cell death after 30 min of stress. Addition of 1 mM glycine betaine or 0.5 mM sucrose reduced the damage. Low-salinity adaptation was achieved in the exponential-phase cells but not in the stationary-phase cells. Significant protection against lethal low-salinity stress was attained when the cells were adapted for as little as 1.5 min. The adapted cells were significantly protected against lethal low salinity and 2.4% sodium sorbate but sensitized to the challenge of heat (52°C) and acid (pH 3.2). Nonlethal lowsalinity treatment of seafood should be avoided to prevent stress adaptation of V. vulnificus.

Challenges for Diadromous Fishes in a Dynamic Global Environment

2009 ◽  
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Generalized Additive Models ◽  
Habitat Characteristics ◽  
Explanatory Variables ◽  
Temperature And Precipitation ◽  
Management Plans ◽  
The Face ◽  
Uncertain Future ◽  
Diadromous Species

<em>Abstract</em>.-Climate change can have an effect on species distributions. The 1900 distribution and potential future distribution of diadromous fish in Europe, North Africa, and the Middle East were explored using generalized additive models (GAMs) and selected habitat characteristics of 196 basins. Robust presence-absence models were built for 20 of the 28 diadromous species in the study area using longitude, annual temperature, drainage surface area, annual precipitation, and source elevation as explanatory variables. Inspection of the relationship between each variable and species presence-absence revealed that the GAMs were generally interpretable and plausible. Given the predicted rise in annual temperature in climate models ranging between 1°C and 7°C by 2100, the fish species were classified according to those losing suitable basins, those gaining suitable basins, and those showing little or no change. It was found that the climate envelopes based on temperature and precipitation for diadromous species would, in general, be shifted farther northeastwards by 2100, and these shifting ranges were comparable with those assessed in other studies. The uncertain future of some species was highlighted, and it was concluded that conservation policy and management plans will need to be revised in the face of climate change.

Challenges for Diadromous Fishes in a Dynamic Global Environment

2009 ◽  
Keyword(s):  
New Technology ◽  
Data Retrieval ◽  
Ecosystem Approach ◽  
Migration Behavior ◽  
Fully Integrated ◽  
Return Rates ◽  
Archival Tags ◽  
Acoustic Tags ◽  
Electronic Tags ◽  
Diadromous Species

<em>Abstract</em>.-Tagging fish with electronic tags can provide information on movement, migration, behavior, and stock structure while diadromous species are at sea. The state of the art technology for tracking fishes in the marine environment includes two families of tags. Archival tags store data and either relay them to satellites or require recapture for interrogation. Low return rates for diadromous species make these tags very expensive to use. A second type, acoustic tags, sends signals to passive receivers. Information is collected from the fish only when it is within range of a receiver. Technology is now being developed to mesh these tags into a fully integrated tag that will permit archived data to be transmitted acoustically over multiple frequencies to receivers allowing data retrieval without recapturing the animal. The new technology includes a "business card" tag that is a miniaturized receiver coupled with a coded pulse transmitter. These tags will exchange and record individual-specific codes when two animals carrying them come within acoustic range of each other, which will allow data from many animals to be moved ashore through few animals. These devices would be ideal for quantifying the degree of school fidelity (or, conversely, mixing) or the degree of at sea interaction of fishes from different river systems and provide ecological information to enhance management in an ecosystem approach to fisheries.

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