Physiological Effects of Brief Air Exposure in Exhaustively Exercised Rainbow Trout (Oncorhynchus mykiss): Implications for "Catch and Release" Fisheries

1992 ◽  
Vol 49 (6) ◽  
pp. 1157-1162 ◽  
Author(s):  
R. A. Ferguson ◽  
B. L. Tufts
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Blood Gases ◽  
Control Fish ◽  
Additional Stress ◽  
Physiological Effects ◽  
Air Exposure ◽  
Catch And Release ◽  
Extracellular Acidosis ◽  
Rainbow Trout Oncorhynchus Mykiss

Rainbow trout (Oncorhynchus mykiss) which were air exposed for 60 s after exhaustive exercise initially had a much larger extracellular acidosis than trout which were only exercised. In both groups, however, plasma pH returned to normal by 4 h. Blood lactate concentrations were also greater in the air-exposed fish and continued to increase throughout the experiment. During air exposure, there was retention of carbon dioxide in the blood, and oxygen tension (Po2) and hemoglobin:oxygen carriage (Hb:O2) both fell by over 80%. After 30 min of recovery, however, blood gases resembled those in fish which were only exercised. Finally, survival after 12 h was 10% in control fish and 88% in the exercised fish but fell to 62 and 28% in fish which were air exposed for 30 and 60 s, respectively, after exercise. These results indicate that the brief period of air exposure which occurs in many "catch and release" fisheries is a significant additional stress which may ultimately influence whether a released fish survives.

Consequences of Pulsed DC Electrofishing and Air Exposure to Rainbow Trout (Oncorhynchus mykiss)

1994 ◽  
Vol 51 (8) ◽  
pp. 1791-1798 ◽  
Author(s):  
C. J. A. Mitton ◽  
D. G. McDonald
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Additional Stress ◽  
Physical Damage ◽  
Early Recovery ◽  
Air Exposure ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Pulsed Dc ◽  
Fish Collection ◽  
Stimulation Of

Electrofishing, a technique widely used for fish collection, is a procedure that is often followed by handling and air exposure before fish are released. In this study the pathological and physiological consequences of capture with pulsed DC (pDC) electroshock with and without the additional disturbance of air exposure were examined on rainbow trout (Oncorhynchus mykiss). Electroshocked fish showed no evidence of direct mortality, and skeletal damage was only induced under the most severe conditions (~600-g fish, 600 V, 20 or 40 s). Physiological disturbances induced by pDC, in the absence of physical damage, consisted of lactacidosis and stimulation of the interrenal stress response. The acidosis was likely induced by tetany during immobilization and apnea during immobilization and early recovery. In fact, the physiological disturbances induced by pDC were similar in magnitude and duration to 2–3 min of exhaustive exercise and generally more severe than responses previously reported for nonpulsed (i.e., continous) DC gear. In addition, following pDC, fish appeared to experience a mild narcosis, as was evident by a reduced response to the additional stress of air exposure.

Effects of Electroshock, Air Exposure, and Forced Exercise on Swim Performance in Rainbow Trout (Oncorhynchus mykiss)

1994 ◽  
Vol 51 (8) ◽  
pp. 1799-1803 ◽  
Author(s):  
C. J. A. Mitton ◽  
D. G. McDonald
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Intracellular Ph ◽  
Physiological Effects ◽  
Air Exposure ◽  
Swim Performance ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Pulsed Dc ◽  
Identical Fashion

Swim performance of rainbow trout (Oncorhynchus mykiss) following forced exercise and pulsed DC electroshock both with and without subsequent air exposure was examined. Swim stamina was assessed by exercising fish at 39 cm/s until exhausted. Swim performance was impaired following all treatments. Increasing durations of air exposure (0–4 min) after electroshock resulted in progressively prolonged durations of swimming impairment (from 1 to 6 h). Electroshock reduced swimming stamina in a virtually identical fashion to that of 5 min of forced exercise. By comparison with the existing literature on the physiological effects of forced exercise, the impairment of swim performance most likely resulted from a reduction in intracellular pH.

Acclimation of Rainbow Trout (Oncorhynchus mykiss) to Low Environmental pH Does Not Involve an Activation of the Pituitary-interrenal Axis, but Evokes Adjustments in Branchial Ultrastructure

1993 ◽  
Vol 50 (12) ◽  
pp. 2532-2541 ◽  
Author(s):  
P. H. M. Balm ◽  
T. G. Pottinger
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Acid Stress ◽  
Ultrastructural Changes ◽  
Control Fish ◽  
Chloride Cells ◽  
Additional Stress ◽  
Exposed Fish ◽  
Rainbow Trout Oncorhynchus Mykiss

Two strains of rainbow trout (Oncorhynchus mykiss) were exposed to soft water at pH 4.0 for 14 days, after ambient pH was reduced gradually. Several parameters, either indicators of acid stress, or reportedly involved in the adaptive response to low pH, were monitored. No mortality occurred during the exposure period; feeding behavior, haematocrit, and plasma protein levels were not affected. A transient depression of leucocrit was observed. A minor, but significant, hypochloremia and perturbations in plasma glucose levels occurred in acid-exposed fish from one strain only. There was no evidence of activation of the pituitary-interrenal axis in acid-exposed fish. Baseline plasma ACTH and Cortisol levels were indistinguishable from those of control fish, and there was no evidence of sensitization to additional stress in acid-exposed fish, in vitro baseline and ACTH-stimulated Cortisol secretion was not significantly different in the two groups. Ultrastructural evidence indicated an increased turnover rate of chloride cells and leucocyte infiltration in gills of acid-exposed fish. These results suggest that interrenal activation and catastrophic ion loss are not inevitable consequences of exposure of rainbow trout to pH 4.0 and that ultrastructural changes in the gills indicate locally regulated adaptive mechanisms.

scholarly journals Immune Response of Rainbow Trout (Oncorhynchus mykiss) to Selected Antigens of Yersinia ruckeri

2009 ◽  
Vol 78 (1) ◽  
pp. 145-150 ◽  
Author(s):  
Unal Ispir ◽  
H. Bayram Gokhan ◽  
Mikail Ozcan ◽  
Mustafa Dorucu ◽  
Naim Saglam
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Metabolic Activity ◽  
Control Fish ◽  
Phagocytic Index ◽  
Control Group ◽  
Yersinia Ruckeri ◽  
Whole Cells ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Fish Group

In this study, effects of Yersinia ruckeri antigens on the immune mechanisms of rainbow trout (Oncorhynchus mykiss) were examined. The weight of the 120 fish used in this study was 20–30 g. After injecting 1 mg of formalin-inactivated whole cells (FKC) and O-antigen (Ag-O) intraperitoneally, blood was taken from the caudal vein of anaesthetized fish and metabolic activity of leukocytes (Nitroblue tetrazolium (NBT) activities), phagocytic activity (PA), phagocytic index (PI), serum protein and serum total immunoglobulin (TIg) levels were determined on day 30 after the first immunization. The same procedure was conducted in the control group. In all the experimental groups, considerable increases in the immune indicators were found and significant differences detected between the control and experimental groups (p < 0.05). Metabolic activity of leukocytes decreased significantly (p < 0.05) during the following treatment with antigens compared to the control fish group.

The adrenergic volume changes of immature and mature rainbow trout (Oncorhynchus mykiss) erythrocytes

2000 ◽  
Vol 203 (19) ◽  
pp. 3025-3031 ◽  
Author(s):  
T. Lecklin ◽  
A. Tuominen ◽  
M. Nikinmaa
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Large Fraction ◽  
Control Fish ◽  
Volume Distribution ◽  
Volume Changes ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Before And After ◽  
Volume Response ◽  
Fluorescence Polarisation

In this study, we examined whether the adrenergic volume response of teleost erythrocytes is related to cell maturity. Rainbow trout (Oncorhynchus mykiss) were made anaemic by reducing their haematocrit to approximately 50 % of the original value. After 3–4 weeks, small, young erythrocytes were seen in the circulation. By measuring the volume distribution of blood samples from anaemic fish before and after noradrenaline stimulation (10 min, 10(−5)mol l(−1) final concentration), we were able to show that the volume response of young, immature erythrocytes to catecholamine stimulation was greater than that of mature erythrocytes. In addition, the membrane fluidity, measured using the steady-state fluorescence polarisation method, was greater in anaemic fish after 24 days of recovery from bleeding than in control fish. Since blood from anaemic fish contained a large fraction of immature erythrocytes, this result indicates that the fluidity of the membrane of immature erythrocytes is greater than that of mature erythrocytes.

Effects of Intermittent Chloramine-T Exposure on Growth, Serum Biochemistry, and Fin Condition of Juvenile Rainbow Trout (Oncorhynchus mykiss)

1994 ◽  
Vol 51 (8) ◽  
pp. 1728-1736 ◽  
Author(s):  
Mark D. Powell ◽  
David J. Speare ◽  
Neil MacNair
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Skin Diseases ◽  
Growth Parameters ◽  
Serum Biochemistry ◽  
Control Fish ◽  
Plasma Sodium ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Chloramine T

Chloramine-T is a commonly used therapeutic agent for the treatment of bacterial gill and skin diseases in the intensive aquaculture of salmonids; however, little is known about its effects on healthy fish. Juvenile rainbow trout (Oncorhynchus mykiss) were exposed weekly to 5, 10, and 20 mg active chloramine-T ingredient∙L−1 in a 20-tank replicate flow-through facility. Control fish were treated with tank water only. Growth parameters and haematocrits were taken twice weekly and serum biochemistry was measured on termination of the experiment. Absolute growth rates were suppressed but only statistically significantly in fish treated with 20 mg chloramine-T∙L−1 compared with controls. Fish exposed to 10 and 20 mg chloramine-T∙L−1 showed significant predisposition to an erosive dermatitis of the caudal fin which appeared to be caused by opportunistic pathogens of the genus Pseudomonas spp. and Flavobacter spp. Haematocrits decreased in controls and ail treatments. A significant concentration-dependent decrease in plasma sodium and chloride was observed. Plasma glucose levels did not vary and were similar to those reported for unstressed trout. We recommend that care be taken when using chloramine-T prophylactically and that concentrations of less than 10 mg∙L−1 be used.

Cell-mediated Immune Response of Rainbow Trout (Oncorhynchus mykiss) to Larval Pseudoterranova decipiens (Nematoda; Ascaridoidea) following Sensitization to Live Sealworm, Sealworm Extract, and Nonhomologous Extracts

1993 ◽  
Vol 50 (1) ◽  
pp. 60-65 ◽  
Author(s):  
N. R. Ramakrishna ◽  
M. D. B. Burt ◽  
B. M. MacKinnon
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Cell Function ◽  
Secondary Response ◽  
Control Fish ◽  
Cell Mediated Immunity ◽  
Specific Response ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Pseudoterranova Decipiens ◽  
Test Fish

The delaved-type hypersensitivity (DTH) reaction (an in vivo manifestation of cell-mediated immunity) was studied in rainbow trout (Oncorhynchus mykiss) exposed to sealworm Pseudoterranova decipiens infections. Test fish immunized with sealworm extract and live intact worms, were compared with control fish which received either phosphate-buffered saline (negative control) or nonhomologous cestode or nematode antigens (positive control). Test fish immunized with sealworm extract produced a typical DTH reaction to live sealworm, challenge. The DTH reaction was similar to that in mammals and showed lymphoid and mononuclear cell infiltration. The electron microscopical studies revealed the presence of activated macrophages and plasma cells in the reaction zone. The specific response, following immunization with homologous antigens, supports the existence of T-cell function with anamnesis in rainbow trout exposed to sealworm antigens. However, when the test fish were immunized with live sealworms and later challenged with live sealworms, the secondary response was poor and showed no difference from controls and naive fish.

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