Elimination of Hexachlorobenzene (HCB) by Rainbow Trout (Salmo gairdneri), and an Examination of its Kinetics in Lake Ontario Salmonids

1981 ◽  
Vol 38 (11) ◽  
pp. 1350-1356 ◽  
Author(s):  
A. J. Niimi ◽  
C. Y. Cho

Subadult rainbow trout (Salmo gairdneri) were fed diets containing hexachlorobenzene (HCB) to establish mean body burdens of 225 and 440 μg HCB per fish. They were sampled after 0, 24, 55, and 110 d to estimate the rate of elimination. The biological half-life or T[Formula: see text] of HCB for trout under the prescribed laboratory conditions was estimated to be at least 7 mo, and perhaps as long as several years. T[Formula: see text] was calculated using body burden or μg HCB per fish, and tissue concentrations or μg/kg HCB. Estimates of T[Formula: see text] derived from tissue concentrations ranged from 61 to 117 d, but this was shown to be due to a relative increase in body weight over the study period. The implications of increasing body weight on kinetics measurements are discussed, and an equation is presented that adjusts for changes in body weight where estimates of T[Formula: see text] are calculated using tissue concentrations.The results of this and other studies on HCB were used to examine the kinetics of HCB in salmonids collected from Lake Ontario. Using the information derived from laboratory studies on rainbow trout, good agreement was achieved between the expected level and that monitored in field samples of rainbow trout, but only a fair agreement was suggested for lake trout (Salvelinus namaycush) and coho salmon (Oncorhynchus kisutch). Differences in the HCB kinetics of these species may be attributed to body weight, age, and perhaps feeding habits. Concentrations of HCB reported in field sampling programs generally range from 1 to 100 μg/kg in fish, and it is suggested that these levels are primarily due to the limited availability of HCB in the Lake Ontario environment.Key words: contaminants, hexachlorobenzene (HCB), half-life, elimination, depuration, rainbow trout, Salmo gairdneri; Lake Ontario


1983 ◽  
Vol 40 (11) ◽  
pp. 1987-1994 ◽  
Author(s):  
J. W. Hilton ◽  
P. V. Hodson ◽  
H. E. Braun ◽  
J. L. Leatherland ◽  
S. J. Slinger

Juvenile rainbow trout were reared for 24 wk on practical-type diets formulated with fish meals derived from coho salmon (Oncorhynchus kisutch) taken from Lake Michigan, Lake Ontario, and the Pacific Ocean. Levels of contaminants (DDT, chlordane, dieldrin, mirex, and PCBs) increased 10-fold from control and Pacific Ocean salmon-based diets to Lake Ontario salmon-based diets. Rainbow trout accumulated contaminants in direct proportion to dietary levels. However, there were no significant differences in the final body weights, feed to gain ratios, or mortality rates of the trout reared on the different test diets. No signs of abnormal behavior or any indication of histopathological abnormalities were observed in any of the fish. There were no signs of thyroid hyperplasia or any significant decline in serum T3 or T4 levels with increasing dietary contaminant levels. Therefore, rainbow trout do not appear to have been affected by the uptake and accumulation of contaminants. However, the trout did not appear to regulate their body burden of contaminants; this ultimately could prove to be toxic and may adversely affect the ability of these fish to reproduce and survive. The final concentrations of mirex and PCBs in the Lake Ontario-fed fish exceeded the allowed limits to protect human health; therefore, fish meals produced from Lake Ontario salmon are unsuitable as a source of feed for aquaculture of rainbow trout intended for human consumption.



1969 ◽  
Vol 26 (7) ◽  
pp. 1801-1812 ◽  
Author(s):  
John T. Windell ◽  
David O. Norris ◽  
James F. Kitchell ◽  
James S. Norris

Quantitative data are presented for three laboratory experiments concerning rate of gastric evacuation of pellets (fed in gelatin capsules) and pellet components. Rainbow trout, Salmo gairdneri, acclimated to a constant water temperature of 15 C were killed 12 hr after consuming an experimental meal. Subtraction of amount of dry matter remaining at autopsy from dry matter consumed yielded amount of food digested or evacuated or both, from the stomach per unit time.Meals of encapsulated pellet were evacuated from the stomach more rapidly (65.8% decrease in 12 hr) than encapsulated corn oil (42.6%), gelatin (50.8%), a combination of corn oil and gelatin (47.3%), saturated fat (28.8%), or methyl cellulose (50.3%).Groups of fish consuming five capsules equal to approximately 0.65 % of their body weight evacuated 35.9, 45.1, 64.2, 95.5, and 100% at intervals after killing from 6 to 36 hr, respectively. Similar groups consuming seven capsules equal to approximately 1.0% of their body weight evacuated 23.7, 57.9, 70.5, and 86.6% at intervals after killing from 4 to 20 hr, respectively.Ten groups of trout consuming amounts of dry matter equal to 0.24, 0.40, 0.74, 1.11, 1.31, 1.19, 1.59, 1.56, 1.91, and 2.26% of their body weight evacuated 90.7, 81.3, 64.2, 57.9, 56.6, 52.5, 53.4, 51.3, 58.7, and 50.0% in 12 hr, respectively. Gastric motility remains relatively constant once food has entered the stomach. However, when larger meals are fed a greater quantity is evacuated per unit time. This could only be accomplished by changes in volume of gastric contents pumped per peristaltic stroke or number of strokes per unit time.



1976 ◽  
Vol 33 (12) ◽  
pp. 2699-2702 ◽  
Author(s):  
Gary A. Wedemeyer

Moving 4–5-in. coho salmon (Oncorhynchus kisutch) held in soft (20 ppm CaCO3) water from the relatively light loading density of 0.5 lb/ft3 to 1, 2, or 4 lb/ft3 (density index, DI = 0.1, 0.2, 0.4, 0.8) caused significant stress as indicated by loss of feeding behavior, but only minimal physiological disturbances, as indicated by lack of hyperglycemia or hypochloremia. However, moving them to 6 or 12 lb/ft3 (DI = 1.2, 2.4) caused significant physiological stress which required at least a week for recovery. Smolting coho salmon were physiologically stressed by population densities of 1 lb/ft3 or more and a subclinical corynebacterial kidney infection was activated. Rainbow trout (Salmo gairdneri) (4–5 in.) were physiologically stressed when moved and held at 1 lb/ft3 or more but retained normal feeding behavior. This indicates that handling and crowding stress will be minimized in softwater areas if densities in fish distribution trucks or in ponds or raceways during disease treatments are held to 0.1–0.5 lb/gal.



1983 ◽  
Vol 40 (3) ◽  
pp. 306-312 ◽  
Author(s):  
A. J. Niimi

Rainbow trout (Salmo gairdneri), white sucker (Catostomus commersoni), white bass (Morone chrysops), smallmouth bass (Micropterus dolomieui), and yellow perch (Perca flavescens) were collected from Lakes Ontario and Erie to examine the relationship between contaminant levels in females and their eggs. Factors such as the percent lipid in the fish and percent of total lipid deposited in the eggs significantly influenced (P < 0.01) contaminant transfer. The percentages of the 9–11 organic contaminants transferred generally showed less variation within a species than the percentages for a substance transferred among the five species examined. This relationship was consistent even though there was over a 10-fold range in contaminant concentrations within a given species. Mercury did not demonstrate this response because the percentage in eggs was low for all species. The levels of PCB monitored in eggs of rainbow trout collected from Lake Ontario suggest that egg and fry survival rates could be affected based on the toxicological evidence from other studies. An examination of the possible effects of spawning on the kinetics of contaminants among these species suggests that relative body concentrations of organic contaminants may be decreased by 5% or be increased by 10%, and mercury levels may be increased by 6–22% following the deposition of eggs. The amount of change varies with species and is influenced by the percent egg weight of body weight, and the rate of contaminant transfer from females to eggs.Key words: toxicology, contaminants, reproduction, Lake Ontario, Lake Erie



1973 ◽  
Vol 30 (9) ◽  
pp. 1301-1308 ◽  
Author(s):  
Dana C. Schmidt ◽  
L. J. Weber

The plasma half-life of sulfobromophthalein (BSP) for rainbow trout (Salmo gairdneri) was 13 min for doses of 5 and 10 mg/kg and 29 min for a dose of 15 mg/kg. The biliary BSP transport maximum (Tm) averaged 9.6 μg/min per kg for five fish while the blood clearance averaged 1.7 ml/min per kg for two fish. Normal bile flows of 0.87 μliter/min per kg in trout were increased upon anesthetization but were unaffected in fish allowed to recover from spinal transection. Spinal transection did not affect the plasma half-life of BSP.The data presented support the conclusion that the transport of BSP from liver cells to bile is the rate-limiting step in the excretion of this dye. When the BSP Tm of trout was compared to literature values for mammals and dogfish (Squalus acanthias), large differences were found which were probably caused by effects of different temperatures and blood flows. When the Tm values of the various species were based on blood clearance of BSP (reflecting liver blood flow) the differences were greatly reduced, suggesting similar abilities of the liver of the various species to excrete this dye.





1976 ◽  
Vol 33 (5) ◽  
pp. 1205-1208 ◽  
Author(s):  
Wilma M. Ord ◽  
Monique Le Berre ◽  
Pierre de Kinkelin

Rainbow trout (Salmo gairdneri) fry and yearlings were compared with hybrids of rainbow trout and coho salmon (Oncorhynchus kisutch) for susceptibility to viral hemorrhagic septicemia (VHS). In three trials, exposure to waterborne infectivity consistently resulted in a 77% mortality of rainbow trout fry while loss among the hybrid fry averaged only 11%. Tests showed survivors might be carriers of virus. Hybrid yearlings infected by gill brushing were fully refractory to VHS whereas mortality (3:8) and viremia were recorded among gill-infected rainbow trout yearlings.



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