Reproduction in Brook Trout (Salvelinus fontinalis) Fed Sublethal Concentrations of DDT

1968 ◽  
Vol 25 (9) ◽  
pp. 1787-1796 ◽  
Author(s):  
Kenneth J. Macek

When sexually maturing yearling brook trout were fed for 156 days with DDT at rates that evidently caused no mortality, fish fed at the lower dosages produced more mature ova than untreated fish. Those fed at the highest dosage produced fewer mature ova than untreated fish. The size of the male fish at the end of the feeding period tended to increase according to dosage of DDT. In eggs and sac fry obtained from various mating combinations of gametes from the experimental groups, mortality was with one exception higher when at least one of the gametes came from treated fish than when they both came from untreated fish. A major portion of the mortality of sac fry in groups where the eggs came from treated fish occurred during the 15th week of development. This period coincided with the period of maximum, utilization of yolk fat reported to occur in other salmonid fry, and indicated that insecticide residues in the eggs were released at this time and resulted in the observed mortality. The residue concentrations in the fish at the end of the feeding period were similar to those reported for wild fish.

1986 ◽  
Vol 43 (10) ◽  
pp. 2048-2050 ◽  
Author(s):  
W. H. Tam ◽  
P. D. Payson ◽  
R. J. J. Roy

Brook trout fry (Salvelinus fontinalis) were exposed to pH 4.66 for various durations up to 141 d and then returned to neutral water. Growth of test fish was in general significantly lower than that of control fish for exposures up to days 45–78. In four of six groups of acid-treated fish, growth eventually recovered and the growth rates were not different from that of control fish. The results suggested that growth inhibition was induced early in the exposure to sublethally low pH and that recovery in the latter phase of the experiment occurred whether pH remained acidic or was readjusted to neutral.


1991 ◽  
Vol 48 (10) ◽  
pp. 1989-1995 ◽  
Author(s):  
R. L. Walker ◽  
C. M. Wood ◽  
H. L. Bergman

Adult brook trout (Salvelinus fontinalis; 200–300 g) were preexposed for 10 wk to 75 μg Al3+∙L−1, pH = 5.2, in soft water (25 μequiv Ca2+∙L−1) and controls to the same conditions without Al3+. When challenged with a lethal dose of Al3+ (333 μg∙L−1) at the same pH (5.2) and Ca2+ (25 μequiv∙L−1), the control fish demonstrated a twofold increase in ventilation volume and ventilatory stroke volume within the first two hours, an increase in [Formula: see text], and a decrease in pHa and hemoglobin O2 saturation. These effects were not seen in the group chronically preexposed to sublethal Al, indicating that some acclimation had occurred. Although the prechallenge [Formula: see text] and [Formula: see text] were the same in the two groups, the arterial pH, plasma [HCO3−], and hemoglobin O2 saturation of the Al-preexposed fish were significantly below those of the control fish, suggesting that the acclimation was achieved at some cost. Possible mechanisms are discussed.


1975 ◽  
Vol 53 (6) ◽  
pp. 666-670 ◽  
Author(s):  
H. C. Freeman ◽  
D. R. Idler

Livers from brook trout (Salvelinus fontinalis) held in water containing 3.8 p.p.m. (mg/1) Corexit and in water containing 3.8 p.p.m. Corexit + 0.2 p.p.m. polychlorinated biphenyl (PCB) were firmer in texture than livers taken from control trout held in fresh water. The testes from the PCB-treated trout were darker in color, smaller in size, contained less spermatic fluid, and appeared to be regressed when compared with testes from the control fish.Only 72% of the eggs from PCB-treated trout hatched compared to 92% for control eggs when eggs were incubated in fresh water. Fertilized eggs incubated in water containing 0.2 p.p.m. PCB + 3.8 p.p.m. Corexit resulted in less than 1% of the eggs from the untreated fish and none of the eggs from PCB-treated fish being hatched. The young fish from the control group lived only a few days in the water containing PCB.PCB greatly stimulated the in vitro 11β-hydroxylation of testosterone by trout testicular tissue. There was no significant change in 11-ketotestosterone blood levels in maturing brook trout after treatment with 3.8 p.p.m. Corexit or 3.8 p.p.m. Corexit + 0.2 p.p.m. PCB for 21 days during the final stages of maturation. It is thought that sublethal levels of PCB can interfere with the reproduction process in this species.


1971 ◽  
Vol 28 (4) ◽  
pp. 509-512 ◽  
Author(s):  
Akira Saito ◽  
L. W. Regier

Shrimp and crab wastes were fed to yearling brook trout for 12 weeks. Diets containing 20 and 30% shrimp waste, 20% crab waste, and 0.004% canthaxanthin were compared with a commercial trout diet. The carotenoid contents of the flesh and skin were highest with the canthaxanthin-fed fish, but the 20% shrimp-waste-fed fish had the most desirable color visually within the feeding period used.


1974 ◽  
Vol 31 (4) ◽  
pp. 449-452 ◽  
Author(s):  
James M. McKim ◽  
Duane A. Benoit

Exposure of brook trout (Salvelinus fontinalis) to sublethal concentrations of copper from yearlings through spawning to 3-mo juveniles was found sufficient to establish a "no effect" concentration. No adverse effects were found on survival, growth, or reproductive capacity of trout exposed in a second generation from egg through spawning to copper concentrations (about 9.4, 6.1, and 4.5 μg/liter) which had caused no adverse effects on their parents when exposed to similar concentrations from yearlings to spawning. Nor were any adverse effects found on survival or growth of their offspring when exposed to the same concentrations from hatching to age 90 days. Tissue residue analyses indicated no copper accumulation in gill, liver, kidney, or muscle of either first- or second-generation trout exposed to the various copper concentrations, and residues in unfertilized eggs from exposed females were similar to those in females not exposed to added copper.


Parasitology ◽  
1982 ◽  
Vol 85 (3) ◽  
pp. 495-501 ◽  
Author(s):  
P. Brassard ◽  
M. E. Rau ◽  
M. A. Curtis

Guppies (Lebistes reticulatis) exposed to doses as low as 25 cercariae of Diplostomum spathaceum for 30 min were consistently and significantly more susceptible to predation by brook trout (Salvelinus fontinalis) than uninfected controls. The increase in susceptibility to predation was correlated with a marked decrease in the activity of infected fish.


2016 ◽  
Vol 73 (1) ◽  
pp. 94-104 ◽  
Author(s):  
Elsa Goerig ◽  
Theodore Castro-Santos ◽  
Normand Émile Bergeron

Culverts can restrict access to habitat for stream-dwelling fishes. We used passive integrated transponder telemetry to quantify passage performance of >1000 wild brook trout (Salvelinus fontinalis) attempting to pass 13 culverts in Quebec under a range of hydraulic and environmental conditions. Several variables influenced passage success, including complex interactions between physiology and behavior, hydraulics, and structural characteristics. The probability of successful passage was greater through corrugated metal culverts than through smooth ones, particularly among smaller fish. Trout were also more likely to pass at warmer temperatures, but this effect diminished above 15 °C. Passage was impeded at higher flows, through culverts with steep slopes, and those with deep downstream pools. This study provides insight on factors influencing brook trout capacity to pass culverts as well as a model to estimate passage success under various conditions, with an improved resolution and accuracy over existing approaches. It also presents methods that could be used to investigate passage success of other species, with implications for connectivity of the riverscape.


1972 ◽  
Vol 29 (11) ◽  
pp. 1615-1624 ◽  
Author(s):  
James E. Bryan ◽  
P. A. Larkin

Analyses of stomach contents showed that the kinds of prey eaten by brook trout (Salvelinus fontinalis), cutthroat trout (Salmo clarki), and rainbow trout (Salmo gairdneri) were seldom distributed at random among the individuals. Repeated observation of food eaten by individuals in a stream and ponds showed that prey types were eaten in proportions which were characteristic for an individual.Specialization occurred on several different kinds of prey. Although the degree of specialization was higher during shorter intervals, the data suggested that some specialization persisted for half a year. There were no striking correlations between degree of specialization and other individual properties such as size, growth rate, weight of food, number of food items, previous specialization, or area of recapture.In addition to the observations on trout in relatively undisturbed habitats, a field experiment was conducted using laboratory-reared rainbow trout held in small ponds. The food of each trout in the experiment was sampled repeatedly. In analysis of variance, interaction among the individuals and kinds of prey eaten showed that food specialization occurred. Both the absolute and relative abundance of potential prey were constant during the experiment.


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