Contaminant Accumulation and Physiological Response in Rainbow Trout (Salmo gairdneri) Reared on Naturally Contaminated Diets

1983 ◽  
Vol 40 (11) ◽  
pp. 1987-1994 ◽  
Author(s):  
J. W. Hilton ◽  
P. V. Hodson ◽  
H. E. Braun ◽  
J. L. Leatherland ◽  
S. J. Slinger
Keyword(s):  
Rainbow Trout ◽  
Pacific Ocean ◽  
Lake Michigan ◽  
Coho Salmon ◽  
Body Burden ◽  
Lake Ontario ◽  
Abnormal Behavior ◽  
Salmo Gairdneri ◽  
Human Consumption ◽  
Thyroid Hyperplasia

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.

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
Keyword(s):  
Body Weight ◽  
Rainbow Trout ◽  
Half Life ◽  
Coho Salmon ◽  
Feeding Habits ◽  
Lake Ontario ◽  
Salmo Gairdneri ◽  
Tissue Concentrations ◽  
Field Samples ◽  
Kinetics Of

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

Electrophysiological Studies of Morpholine-Imprinted Coho Salmon (Oncorhynchus kisutch) and Rainbow Trout (Salmo gairdneri)

1976 ◽  
Vol 33 (4) ◽  
pp. 688-694 ◽  
Author(s):  
Jon C. Cooper ◽  
Arthur D. Hasler
Keyword(s):  
Rainbow Trout ◽  
Lake Michigan ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Control Fish ◽  
Salmo Gairdneri ◽  
Paired Group ◽  
Naturally Occurring ◽  
Data Support ◽  
Electrophysiological Studies

Two groups of coho salmon (Oncorhynchus kisutch) were exposed to a 5 × 10−5 mg/liter concentration of a synthetic chemical, morpholine, for 4 wk during the smolting period, while two corresponding groups were left unexposed (controls). All groups were marked by finclipping and stocked into Lake Michigan near the mouth of Oak Creek (South Milwaukee, Wisconsin). A second series of exposed and unexposed salmon was released 13 km north of Oak Creek. Rainbow trout (Salmo gairdneri) were tested in a similar experiment.Homing salmonids were censused and then used in physiological experiments. Electroencephalographic studies showed significantly greater responses by the experimental (exposed) compared to control fish to 1% morpholine (P ≤ 0.001 − 0.05) and by one paired group to a stream sample scented with morpholine (about 10−3 mg/liter morpholine P ≤ 0.01). Responses to morpholine were specific in that another chemical similar to it did not elicit responses. These data support the olfactory hypothesis that salmon may imprint to naturally occurring homestream odors in the same way as they do to morpholine.

Physiological Response of Juvenile Coho Salmon (Oncorhynchus kisutch) and Rainbow Trout (Salmo gairdneri) to Handling and Crowding Stress in Intensive Fish Culture

1976 ◽  
Vol 33 (12) ◽  
pp. 2699-2702 ◽  
Author(s):  
Gary A. Wedemeyer
Keyword(s):  
Rainbow Trout ◽  
Feeding Behavior ◽  
Coho Salmon ◽  
Physiological Stress ◽  
Oncorhynchus Kisutch ◽  
Fish Distribution ◽  
Salmo Gairdneri ◽  
Crowding Stress ◽  
Normal Feeding ◽  
Intensive Fish Culture

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.

Density, growth, and change in density of coho salmon and rainbow trout in three Lake Michigan tributaries

1983 ◽  
Vol 61 (5) ◽  
pp. 1120-1127 ◽  
Author(s):  
L. M. Carl
Keyword(s):  
Rainbow Trout ◽  
Growth Rates ◽  
Lake Michigan ◽  
Coho Salmon ◽  
Daily Growth ◽  
Salmon Fry ◽  
Daily Change ◽  
Early Fall ◽  
Growth And Change ◽  
Downstream Movement

Coho salmon spawning peaked in the late fall. Spawning densities ranged from fewer than 5 coho salmon per hectare up to 90 fish per hectare. Subyearling coho salmon densities ranged from 10 to 60 fish per 100 m2 in June and dropped to 5–20 fish by early fall. Coho salmon fry increased in length from 40 mm in early May, to over 120 mm by smolt out-migration in the following April. Coho salmon instantaneous daily change in density coefficients ranged from 0.004 to 0.019 and were dependent on initial coho density. Daily coho salmon growth rates ranged from 0.38 to 0.60 mm per day and were not dependent on initial coho salmon density. Downstream movement of rainbow trout fry began in May, and continued into July. In the spring 10–20 yearlings and one to five 2-year-olds per 100 m2 were present. Most fry emerged in June at a size of 25 mm and grew to 85 mm by fall. Daily growth rates varied from 0.23 to 0.45 mm per day for yearling rainbow trout and were not correlated with rainbow trout density.

Biological and Toxicologtcal Effects of Environmental Contaminants in Fish and Their Eggs

1983 ◽  
Vol 40 (3) ◽  
pp. 306-312 ◽  
Author(s):  
A. J. Niimi
Keyword(s):  
Rainbow Trout ◽  
Organic Contaminants ◽  
Yellow Perch ◽  
Survival Rates ◽  
Lake Ontario ◽  
Smallmouth Bass ◽  
Salmo Gairdneri ◽  
White Bass ◽  
Morone Chrysops ◽  
Contaminant Transfer

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

Viral Hemorrhagic Septicemia: Comparative Susceptibility of Rainbow Trout (Salmo gairdneri) and Hybrids (S. gairdneri × Oncorhynchus kisutch) to Experimental Infection

1976 ◽  
Vol 33 (5) ◽  
pp. 1205-1208 ◽  
Author(s):  
Wilma M. Ord ◽  
Monique Le Berre ◽  
Pierre de Kinkelin
Keyword(s):  
Rainbow Trout ◽  
Experimental Infection ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Salmo Gairdneri ◽  
Viral Hemorrhagic Septicemia ◽  
Comparative Susceptibility

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.

The division process of Cryptobia salmositica in experimentally infected rainbow trout (Salmo gairdneri)

1978 ◽  
Vol 56 (7) ◽  
pp. 1514-1518 ◽  
Author(s):  
Patrick T. K. Woo
Keyword(s):  
Rainbow Trout ◽  
Nuclear Division ◽  
Coho Salmon ◽  
The Body ◽  
Binary Fission ◽  
Salmo Gairdneri ◽  
Division Process

Cryptobia salmositica was isolated from its vector, Piscicola salmositica, which was collected from spawning salmon. The organisms were first injected into coho salmon and then maintained in rainbow trout. The process of multiplication is described from Giemsa's stained smears. The first stage of division is the production of two new flagella (one long and one short). This is followed by nuclear division which is not completed until kinetoplast division is completed. Body division commences from the posterior end soon after the long flagellum attaches to the body. Following this, the nucleus, the kinetoplast, and the blepharoplast migrate into the newly divided part of the organism. Final body division is completed after the migration of these organelles. Multiplication of C. salmositica is by unequal longitudinal binary fission.

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