scholarly journals Influence of Salinity on Physiological Response of the Bearded Horse Mussel Modiolus barbatus and Noah’s Ark Shell Arca noae

2018 ◽  
Vol 37 (4) ◽  
pp. 345-357
Author(s):  
Matea Vlašić ◽  
Nikša Glavić ◽  
Jakša Bolotin ◽  
Enis Hrustić ◽  
Iris Dupčić Radić

AbstractBearded horse mussel Modiolus barbatus and Noah’s ark shell Arca noae are a species of interest for the diversifying shellfish aquaculture on the south-eastern coast of the Adriatic. In this study, oxygen consumption (OC), total ammonia excretion (TAM) and clearance rate (CR) responses to the changes in seawater salinity (37, 30, 25 and 20) were investigated in the laboratory. There is a statistically significant influence of salinity on oxygen consumption and TAM excretion of Noah’s ark shell, while the time of exposure to different salinities is significantly correlated to TAM excretion by the bearded horse mussel. Mean OC of Noah’s ark shell ranged from 0.14 ± 0.06 to 0.54 ± 0.27 mg O2g−1h−1 and that of bearded horse mussel from 0.18 ± 0.17 to 0.26 ± 0.14 mg O2g−1h−1. Mean values of TAM excretion of Noah’s ark shell ranged from 2.14 ± 1.52 to 7.22 ± 6.04 μmol g−1 h−1 and for bearded horse mussel from 0.98 ± 0.53 to 2.78 ± 2.96 μmol g−1 h−1. Salinity and exposure time have a significant influence on the CR of Noah’s ark shell, whilst salinity has been found to be the determining factor for the bearded horse mussels’ CR. Mean values of Noah’s ark shell CR ranged from 0.96 ± 0.54 to 4.18 ± 1.15 l h−1g−1 and for bearded horse mussel from 2.43 ± 0.99 to 4.23 ± 0.84 l h−1g−1. Higher oxygen consumption to total ammonia excretion (O:N) ratios at lower salinities indicated the use of proteins as a metabolic substrate for both species. Noah’s ark shell has greater energy expenditure related to respiration and TAM excretion than the bearded horse mussel.

1979 ◽  
Vol 36 (6) ◽  
pp. 621-629 ◽  
Author(s):  
Betty A. Hillaby ◽  
David J. Randall

Acute ammonia toxicity in rainbow trout (Salmo gairdneri) was studied by intraarterial injection of NH4Cl and NH4HCO3. Hydrogen ion and total ammonia concentrations were measured in blood sampled from the dorsal aorta both before and after injection. Although injection of NH4HCO3 increased arterial blood pH, and injection of NH4Cl decreased arterial blood pH, the same dose of each was required to kill fish. While the un-ionized form of ammonia in water has been shown to be toxic, in the blood either the ionized form or the total ammonia load is toxic to fish. Ammonia levels were measured in pre- and postbranchial blood. Mean values were not significantly different, but paired values indicated a fall in blood ammonia due to excretion across the gills. There appears to be a more rapid excretion of ammonia following NH4HCO3 infusions, which result in higher un-ionized ammonia levels in blood compared with those following NH4Cl infusions. These results are consistent with the hypothesis that ammonia is excreted in the un-ionized form. Key words: un-ionized ammonia, ionized ammonia, gills, pH, blood


2014 ◽  
Vol 62 (4) ◽  
pp. 315-321 ◽  
Author(s):  
Vicente Gomes ◽  
Maria José de Arruda Campos Rocha Passos ◽  
Arthur José da Silva Rocha ◽  
Thais da Cruz Alves dos Santos ◽  
Fabio Matsu Hasue ◽  
...  

The energy budget of Antarctic stenothermic and/or stenohaline ectotherms is modulated by variations of temperature and salinity. The joint effects of these latter on polar organisms have been but little studied. Data on this subject are of great importance for an understanding of the energy demand of Antarctic animals such as amphipods, especially when considering their ecological importance and the possible impacts of global changes. Experiments were carried out at the Brazilian Antarctic Station "Comandante Ferraz" under controlled conditions. Specimens of Bovallia gigantea were collected in Admiralty Bay and acclimated to temperatures of 0ºC; 2.5ºC and 5ºC and to salinities of 35, 30 and 25. Thirty measurements were taken for each of the nine possible combinations of the three temperatures and the three salinities. Metabolic rates were assessed based on oxygen consumption and total ammonia nitrogenous excretion in sealed respirometers. At 0ºC and 2.5ºC, the metabolic rates of the animals that were acclimated to salinities of 30 or 35 were similar, indicating a possible mechanism of metabolic independence of temperature. However, the metabolic rates were always higher at 5.0ºC. The effects of temperature on oxygen consumption and on ammonia excretion rates were intensified by lower salinities. Individuals of B gigantea have a temperature-independent metabolic rate within a narrow temperature window that can be modified in accordance with salinity.


2012 ◽  
Vol 21 (3) ◽  
pp. 639-653 ◽  
Author(s):  
Melita Peharda ◽  
Daria Ezgeta-Balić ◽  
John Davenport ◽  
Nedo Vrgoč

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8445
Author(s):  
Yazhou Jiang ◽  
Haifeng Jiao ◽  
Peng Sun ◽  
Fei Yin ◽  
Baojun Tang

Marine mollusks are commonly subjected to heat stress. To evaluate the effects of heat stress on the physiological metabolism of the ark shell Scapharca subcrenata, clams were exposed to different high temperatures (24, 28 and 32 °C) for 72 h. The oxygen consumption and ammonia excretion rates were measured at 2, 12, 24, 48 and 72 h. The results indicated that the metabolic rates of the ark shell significantly increased with increasing heat stress, accompanied by mortalities in response to prolonged exposure. A metabolomics approach based on gas chromatography coupled with mass spectrometry was further applied to assess the changes of metabolites in the mantle of the ark shell at 32 °C. Moreover, multivariate and pathway analyses were conducted for the different metabolites. The results showed that the heat stress caused changes in energy metabolism, amino acid metabolism, osmotic regulation, carbohydrate metabolism and lipid metabolism through different metabolic pathways. These results are consistent with the significant changes of oxygen consumption rate and ammonia excretion rate. The present study contributes to the understanding of the impacts of heat stress on intertidal bivalves and elucidates the relationship between individual-level responses and underlying molecular metabolic dynamics.


Author(s):  
Jose M.F. Babarro ◽  
María José Fernández-Reiriz ◽  
Uxío Labarta

Mussel seed Mytilus galloprovincialis (Bivalvia: Mytilidae) from two origins (rocky shore and collector ropes) was cultivated on a raft in the Ría de Arousa (north-west Spain), from seeding to thinning out, for 226 d (November 1995–July 1996) and two aspects of metabolism, oxygen consumption rate (VO2) and ammonia excretion rate (VNH4-N) were studied in situ.The model derived from multiple analysis of oxygen consumption accounted for 91.9% of the variance, based on dry weight of the mussels and the environmental factors quality of food (organic content) and mainly chlorophyll-a. Seed origin also showed significant influence. The seasonal pattern of the oxygen consumption can be attributed mainly to the variation of chlorophyll-a, which showed a higher range of values in the spring months.Origin of seed did not show a homogeneous effect on oxygen consumption throughout the cultivation period. Collector rope mussels showed higher oxygen consumption values at the beginning of the cultivation period and after the first 15 d, but the rocky shore mussels showed a higher oxygen consumption between days 22 and 110. Energy-conserving patterns and lower condition index at the onset of the experiment for rocky shore mussels could explain these initial differences.Multiple analysis on the variation of ammonia excretion rate provided a model that accounted for 72.6% of the variance based on dry weight of mussels, seed origin and the environmental parameters chlorophyll-a and total particulate matter. The rocky shore mussels showed a significantly higher excretion values for most of the cultivation period, although there was no constant tendency throughout. High excretion values were recorded between January and March, whilst for the rest of the cultivation period values were low.The O:N index was higher in collector rope mussels for most of the cultivation period, which may suggest a more favourable energy metabolism and/or a more appropriate nutritional state for these specimens.


2013 ◽  
Vol 304 (4) ◽  
pp. F422-F431 ◽  
Author(s):  
Jesse M. Bishop ◽  
Hyun-Wook Lee ◽  
Mary E. Handlogten ◽  
Ki-Hwan Han ◽  
Jill W. Verlander ◽  
...  

The ammonia transporter family member, Rh B Glycoprotein (Rhbg), is an ammonia-specific transporter heavily expressed in the kidney and is necessary for the normal increase in ammonia excretion in response to metabolic acidosis. Hypokalemia is a common clinical condition in which there is increased renal ammonia excretion despite the absence of metabolic acidosis. The purpose of this study was to examine Rhbg's role in this response through the use of mice with intercalated cell-specific Rhbg deletion (IC-Rhbg-KO). Hypokalemia induced by feeding a K+-free diet increased urinary ammonia excretion significantly. In mice with intact Rhbg expression, hypokalemia increased Rhbg protein expression in intercalated cells in the cortical collecting duct (CCD) and in the outer medullary collecting duct (OMCD). Deletion of Rhbg from intercalated cells inhibited hypokalemia-induced changes in urinary total ammonia excretion significantly and completely prevented hypokalemia-induced increases in urinary ammonia concentration, but did not alter urinary pH. We conclude that hypokalemia increases Rhbg expression in intercalated cells in the cortex and outer medulla and that intercalated cell Rhbg expression is necessary for the normal increase in renal ammonia excretion in response to hypokalemia.


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