Factors affecting swim bladder volume in rainbow trout (Oncorhynchus mykiss) held in gas supersaturated water

1990 ◽  
Vol 68 (5) ◽  
pp. 962-968 ◽  
Author(s):  
J. M. Shrimpton ◽  
D. J. Randall ◽  
L. E. Fidler
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Partial Pressure ◽  
Strong Dependence ◽  
Arterial System ◽  
Bladder Pressure ◽  
Small Fish ◽  
Swim Bladder ◽  
Factors Affecting ◽  
Rainbow Trout Oncorhynchus Mykiss

We examined the response of the rainbow trout (Oncorhynchus mykiss) swim bladder to gas supersaturated water. Cannulas positioned in the swim bladder of fish were connected to a pressure transducer, allowing direct measurement of swim bladder pressure. When denied access to the surface, fish held in supersaurated water showed an increase in swim bladder pressure. This response showed a strong dependence on the total gas pressure and the oxygen partial pressure of the water. The minimum level of gas supersaturation observed to cause this response corresponds to a ΔP of 27 mmHg [Formula: see text]; 1 mmHg = 133.3 Pa). The threshold ΔP for swim bladder inflation increased as the partial pressure of dissolved oxygen increased. Movement of supersaturated gases from the arterial system into the swim bladder is passive and causes a rise in swim bladder pressure until the diffusion gradient is nil or the gas is expelled through the pneumatic duct. The threshold for release of gas out the pneumatic duct is dependent on the size of the fish. Small fish have higher duct release pressures and are subject to a higher degree of pressure buildup within the swim bladder than larger fish.

Assessing the effects of positive buoyancy on rainbow trout (Oncorhynchus mykiss) held in gas supersaturated water

1990 ◽  
Vol 68 (5) ◽  
pp. 969-973 ◽  
Author(s):  
J. M. Shrimpton ◽  
D. J. Randall ◽  
L. E. Fidler
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Ambient Pressure ◽  
Large Change ◽  
Bladder Volume ◽  
Bladder Pressure ◽  
Small Fish ◽  
Swim Bladder ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
The Impact

We examined the effects of swim bladder overinflation associated with dissolved gas supersaturation on rainbow trout (Oncorhynchus mykiss). The change in swim bladder volume with increased swim bladder pressure was measured in fish subjected to a decrease in ambient pressure. An expansion of swim bladder volume occurs that is related to the excess swim bladder pressure. The volume change results in a decrease in density and positive buoyancy in the fish. Small fish are adversely affected when exposed to gas supersaturated water because of the high swim bladder pressure required to force gas out the pneumatic duct. Changes in behaviour and depth distribution of fish held in gas supersaturated water were measured in a 2 m deep observation column. A large change in density caused small fish to increase depth and compensate for the swim bladder expansion. Although swim bladder inflation occurs for all sizes of trout held in gas supersaturated water, the impact is greatest for small fish and they must compensate by seeking depth. However, adequate depth to compensate for positive buoyancy may not always exist. In such a case, fish must swim continuously in a head down position to overcome excess buoyancy. The power necessary for a fish to swim with an overinflated swim bladder is greatest for small fish that show the largest change in density.

scholarly journals THE EFFECTS OF BRANCHIAL CHLORIDE CELL PROLIFERATION ON RESPIRATORY FUNCTION IN THE RAINBOW TROUT ONCORHYNCHUS MYKISS

1994 ◽  
Vol 197 (1) ◽  
pp. 47-63
Author(s):  
S Bindon ◽  
K Gilmour ◽  
J Fenwick ◽  
S Perry
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Partial Pressure ◽  
Respiratory Function ◽  
Chloride Cell ◽  
Control Fish ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Arterial Blood ◽  
Environmental Hypoxia ◽  
Treated Fish

The objectives of this study were to induce chloride cell (CC) proliferation on the gill lamellae of rainbow trout Oncorhynchus mykiss and to evaluate the consequences for respiratory function. Chronic elevation of hormone levels was used to induce CC proliferation; fish were injected with a combination of cortisol (8 mg kg-1 intramuscularly every day for 10 days) and ovine growth hormone (2 mg kg-1 intraperitoneally every second day for 10 days). The extent of CC proliferation was quantified using scanning electron microscopy and a two-dimensional analysis. An extracorporeal preparation in combination with environmental hypoxia was used to assess the effects of CC proliferation on respiratory function. Arterial blood was routed from the coeliac artery through an external circuit in which pH (pHa), partial pressure of oxygen (PaO2) and partial pressure of carbon dioxide (PaCO2) were monitored continuously. Environmental hypoxia was imposed by gassing a water equilibration column supplying the experimental chamber with N2. The hormone treatment increased the average CC surface area by 2.7-fold and CC density by 2.2-fold; the combined effect was a fivefold increase in CC fractional area. While the PaO2 values of hormone-treated and control fish were similar at PwO2>12.0 kPa, the arterial O2 tensions of treated fish were significantly lower than those of the control group for PwO2¾12.0 kPa. In comparison with control fish at all environmental O2 tensions, the hormone-treated fish exhibited elevated PaCO2 values and a significant acidosis. The effects of CC proliferation on blood gas variables in hormone-treated fish were accompanied by a significantly elevated ventilation amplitude and a lowered ventilation frequency. The results of this study demonstrated (i) that impairment of respiratory gas transfer coincides with CC proliferation, (ii) that O2 and CO2 transfer are influenced differently and (iii) that partial compensation is achieved through physiological adjustments.

scholarly journals In-depth analysis of swim bladder-associated microbiota in rainbow trout (Oncorhynchus mykiss)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Alejandro Villasante ◽  
Carolina Ramírez ◽  
Héctor Rodríguez ◽  
Natalia Catalán ◽  
Osmán Díaz ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Swim Bladder ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Depth Analysis

scholarly journals Dietary low-glucosinolate rapeseed meal affects thyroid status and nutrient utilization in rainbow trout (Oncorhynchus mykiss)

2000 ◽  
Vol 83 (6) ◽  
pp. 653-664 ◽  
Author(s):  
Christine Burel ◽  
Thierry Boujard ◽  
Anne-Marie Escaffre ◽  
Sadasivam J. Kaushik ◽  
Gilles Boeuf ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Fish Meal ◽  
Rapeseed Meal ◽  
Nutrient Utilization ◽  
Antinutritional Factors ◽  
Type I ◽  
Growth Depression ◽  
Factors Affecting ◽  
Rainbow Trout Oncorhynchus Mykiss

Two rapeseed (Brassica napus) meals, RM1 and RM2, with two levels of glucosinolates (GLS; 5 and 41 μmol/g DM respectively) were incorporated at the levels of 300 and 500 g/kg of the diets of juvenile rainbow trout (Oncorhynchus mykiss) in replacement of fish meal, and compared with a fish-meal-based diet. A decrease in the digestibility of the DM, protein, gross energy and P was observed with high-rapeseed meal (RM) incorporation. In trout fed on RM-based diets, growth performance was reduced even after only 3 weeks of feeding. Feed efficiency was adversely affected by RM and GLS intake. Protein and energy retention coefficients were significantly lower in fish fed on the diet containing the higher level of GLS. P retention was significantly lower with all the RM-based diets than with the fish-meal diet. Irrespective of the degree of growth inhibition, fish fed on RM-based diets exhibited similar typical features of hypothyroid condition due to GLS intake, expressed by lower plasma levels of triiodothyronine and especially thyroxine and a hyperactivity of the thyroid follicles. This hypothyroidal condition led to a strong adjustment of the deiodinase activities in the liver, the kidney and the brain. A significant increase of the outer ring deiodinase activities (deiodinases type I and II respectively) and a decrease of the inner ring deiodinase activity (deiodinase type III) were observed. It is concluded that the observed growth depression could be attributed to the concomitant presence of GLS, depressing the thyroid function, and of other antinutritional factors affecting digestibility and the metabolic utilization of dietary nutrients and energy.

Physiological factors affecting triploid production in rainbow trout, Oncorhynchus mykiss

Aquaculture ◽  
1993 ◽  
Vol 114 (1-2) ◽  
pp. 33-40 ◽  
Author(s):  
N.F. Diaz ◽  
P. Iturra ◽  
A. Veloso ◽  
F. Estay ◽  
N. Colihueque
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Physiological Factors ◽  
Factors Affecting ◽  
Rainbow Trout Oncorhynchus Mykiss
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