The development and maturation of vitellogenic oocytes, plasma steroid hormone levels, and gonadotrope activities in acid-stressed brook trout (Salvelinus fontinalis)

1996 ◽  
Vol 74 (4) ◽  
pp. 587-593 ◽  
Author(s):  
W. H. Tam ◽  
Xiaomin Zhang
Keyword(s):  
Food Intake ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Ph Control ◽  
Oocyte Development ◽  
Control Fish ◽  
Control Group ◽  
Food Control ◽  
Neutral Ph ◽  
Sequence Of Events

Brook trout (Salvelinus fontinalis) were divided into a control group at neutral pH, a food-restricted control (Ph–food control) group at neutral pH, and an acid-stressed (pH 4.15) group, and were maintained under these conditions from August 14 to November 1. The food for the pH–food control group was restricted to simulate the reduced food intake of the acid-stressed fish. Throughout September, oocyte development in the acid-stressed fish was accelerated and the oocytes weighed 36–54% more than those of the pH control fish. By late September these oocytes had reached ovulatory size. Then a shift from predominantly high estrogen to high 17α,20β-dihydroxy-4-pregnen-3-one levels occurred in the circulation. Ovulation followed and by October 19 all acid-stressed trout had ovulated. The same sequence of events occurred significantly later in the pH control fish and ovulation was not complete on November 1. Although their oocytes were larger than those of pH control fish in September, hormonal changes and ovulation in pH–food control fish occurred at the same time as in pH control fish. The results suggest that while the reduced food intake during acid stress might have contributed to accelerated oocyte growth, the full effect of chronic acid exposure was responsible for advancing oocyte development, maturation, and ovulation.

Effects of Chronic Exposure to Sublethal pH on Growth, Egg Production, and Ovulation in Brook Trout, Salvelinus fontinalis

1986 ◽  
Vol 43 (2) ◽  
pp. 275-280 ◽  
Author(s):  
W. H. Tam ◽  
P. D. Payson
Keyword(s):  
Brook Trout ◽  
Egg Production ◽  
Salvelinus Fontinalis ◽  
Experimental Period ◽  
The Body ◽  
Oocyte Development ◽  
Control Fish ◽  
Ph Values ◽  
Body Weights ◽  
The Mean

Hatchery-reared brook trout (Salvelinus fontinalis) were maintained in the laboratory at mean pH values of 7.34, 5.56, 5.16, and 4.48 from early February to early December. At pH 4.48, the mean growth rates of males were uniformly lowered during the entire experimental period. Among females, growth was inhibited during the first 5 mo, but their rate of weight gain recovered during the period of rapid oocyte development. At the end of the experiment, the body weights of both male and female fish in pH 5.16 and 4.48 were only 70.70–77.34% of the control fish at pH 7.34. Growth was not affected by exposure to pH 5.56. Rapid oocyte development occurred simultaneously over all pH groups in June, suggesting that the initiation of gametogenesis was not affected over the range of pH tested, the number of eggs produced was significantly correlated to body weight; consequently the number of eggs produced by the smaller pH 5.16–4.48 females was reduced. Ovulation was also significantly delayed in the acidic groups.

Experimental Plantings of Brook Trout (Salvelinus fontinalis) from Furunculosis-Infected Stock

1968 ◽  
Vol 25 (12) ◽  
pp. 2643-2649 ◽  
Author(s):  
L. A. McDermott ◽  
A. H. Berst
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Infected Fish ◽  
Aeromonas Salmonicida ◽  
Control Fish ◽  
Southern Ontario ◽  
Trout Population ◽  
Hatchery Stock ◽  
Associated Species ◽  
Made In

Preliminary sampling revealed the presence of furunculosis disease in the resident brook trout population of the southern Ontario trout stream used in this study.Two plantings of marked yearling brook trout were made in the study area in 1966; one in the spring, and the other in the fall. The spring planting consisted of 1000 brook trout with a predetermined incidence of furunculosis infection and an equal number of trout with no evidence of infection. The fall planting consisted of 2000 brook trout with a known incidence of furunculosis infection.The stream was electrofished periodically during the 2-year period after the first planting. A total of 445 brook trout (140 of the planted hatchery stock, and 305 resident trout) and 127 fish of associated species were captured and examined for the presence of Aeromonas salmonicida, causative agent of furunculosis.Recovery rates of the "infected" and "noninfected" stocks of brook trout were similar, and there was no evidence of transmission of A. salmonicida from the infected fish to the control fish, nor the resident population of brook trout and other species of fish captured.

Retardation and Recovery of Growth in Brook Trout Fry (Salvelinus fontinalis) Exposed for Various Durations to Acidified Water

1986 ◽  
Vol 43 (10) ◽  
pp. 2048-2050 ◽  
Author(s):  
W. H. Tam ◽  
P. D. Payson ◽  
R. J. J. Roy
Keyword(s):  
Growth Inhibition ◽  
Growth Rates ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Low Ph ◽  
Fish Growth ◽  
Control Fish ◽  
Treated Fish ◽  
Test Fish ◽  
Neutral Water

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.

Ovarian cycle and plasma concentrations of estrogen and vitellogenin in brook trout (Salvelinus fontinalis, Mitchill)

1986 ◽  
Vol 64 (3) ◽  
pp. 744-751 ◽  
Author(s):  
W. H. Tam ◽  
R. J. J. Roy ◽  
R. Makaran
Keyword(s):  
Plasma Level ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Plasma Concentrations ◽  
Ovarian Cycle ◽  
Oocyte Development ◽  
Oocyte Growth

Oocyte development and plasma concentrations of estrogen and vitellogenin in brook trout have been investigated. Oocyte development and vitellogenesis resumed immediately after spawning in October, but, up until May, oocytes never developed beyond 1000 μm diameter and yolk deposition only resulted in the appearance of a relatively modest number of fine droplets and globules. A peak occurrence of atretic follicles of about 900μm diameter was observed in March. In May, many cortical alveoli stage oocytes were seen developing from perinucleolar oocytes. From June to October, oocyte growth and vitellogenesis occurred at a faster rate. By the time of ovulation, the oocytes were about 2500 μm in diameter and became filled with a homogeneous mass of yolk. Throughout winter and spring, plasma level of estrogen was 1–5 ng/mL and that of vitellogenin was mostly below 5 μg/mL of alkali-labile protein phosphorus. In October, the plasma concentrations of estrogen and vitellogenin increased to 40 ng/mL and 96 μg/mL, respectively.

scholarly journals The Effect of Non-Circadian Photoperiod on Growth and Puberty Onset of Brook Trout Salvelinus fontinalis Mitchill

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 692
Author(s):  
Katsiaryna Lundova ◽  
Jan Matousek ◽  
Vlastimil Stejskal
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Somatic Growth ◽  
Continuous Light ◽  
Control Group ◽  
Sexually Mature ◽  
Average Body ◽  
Average Body Weight

The aim of the present study was to assess the effects of a prolonged photoperiod on growth rate and sexual maturation in brook trout Salvelinus fontinalis. The task of the experiment was to determine the most effective light regimen capable to minimizing the effects of puberty, including impairment of somatic growth and further general characteristics. In this regard, the studied fish were reared under three photoperiod regimens in which fish were exposed to 24 h continuous light alternating with 24 or 48 h under the ambient photoperiod or 48 h continuous light alternating with a 24 h ambient photoperiod. A control group was reared under the natural ambient photoperiod. Four-hundred and fifty fish with an average initial body weight of 101.3 ± 1.2 g were used for each experimental group (three replicates of each treatment plus control). A statistically lower growth rate showed control groups in both sexes. At the end of the study, control males had an average body weight of 226.6 ± 39.8 g and control females a body weight of 199.8 ± 12.2 g. At the same period, a significantly higher average body weight was found in groups reared 24 h under ambient photoperiod alternating with a 48 h continuous light regime (2CP:1AP) in both sexes (296.56 ± 62.5 g—males, and 239.9 ± 19.2 g—females, respectively). A significantly higher percentage of sexually mature fish was observed in the control group (80% of males and 29% of females, respectively). We found significantly fewer sexually mature females compared to males. The lowest survival was observed in group 2CP:1AP at 92%. It was concluded that regimen under which fish was exposed to 48 h of natural ambient photoperiod alternating with 24 h of constant light (1CP:2AP) lead to the successful delay of gonad development and onset of puberty and increased somatic growth in both sexes.

scholarly journals The Effects of Kefir Usage for Probiotic Purpose on Growth Performance of Brook Trout (Salvelinus fontinalis)

2018 ◽  
Vol 10 (11) ◽  
pp. 101
Author(s):  
Huriye Ariman Karabulut ◽  
Ilker Zeki Kurtoglu ◽  
Ozay Kose
Keyword(s):  
Survival Rate ◽  
Growth Performance ◽  
Brook Trout ◽  
Statistical Difference ◽  
Salvelinus Fontinalis ◽  
The Body ◽  
The Other ◽  
Control Group ◽  
Fish Diet ◽  
Commercial Fish

The effects of probiotically used kefir on growth, survival rate and meat yield characteristics of brook trout (Salvelinus fontinalis) were investigated in this study. For this purpose, kefir was added to trial diets at different rates 20 ml/kg feed (G2), 40 ml/kg feed (G3) while commercial fish feed was used as a control 0 ml/kg feed (G1). Total 270 fish with mean weight 24.38±0.37 g were used during the experiment. Each group had three replicate, and 30 fish were placed in each tank. Experiment was carried on for 90 days. At the end of the experiment, some growth parameters, survival rate and meat yields of the groups were determined. The best weight gain (WG), specific growth rate (SGR), feed conversion ratio (FCR) and survival rate (SR) values were obtained in G2 (20 ml/kg) group (104.31±0.11, 1.30±0.08, 1.40±0.18, 98.88±0.51 respectively). At the end of the study, the differences between the control group and the other groups were not statistically significant in terms of FCR, Condition factor (CF) and survival rate (P < 0.05). However, the differences between the control group and the other groups were statistically significant in terms of WG, WGR and Wf (P < 0.05). The statistical difference between the G2 group and the G1 group was not significant at the SGR, whereas the statistical difference between the G2 group and the G3 group was significant (P < 0.05). The body composition of the fish, hepatosomatic index (HSI), viscerosomatic index (VSI) values, fish meat crude protein and crude fat content were not affected by the addition of kefir to fish diet at different ratios. As a result, it was observed that the addition of kefir at 20% of the diet positively affected the growth performance and survival rate of the brook trout.

Nature and Time Course of Acclimation to Aluminum in Juvenile Brook Trout (Salvelinus fontinalis). II. Gill Histology

1991 ◽  
Vol 48 (10) ◽  
pp. 2016-2027 ◽  
Author(s):  
M. E. Mueller ◽  
D. A. Sanchez ◽  
H. L. Bergman ◽  
D. G. McDonald ◽  
R. G. Rhem ◽  
...  
Keyword(s):  
Brook Trout ◽  
Time Course ◽  
Salvelinus Fontinalis ◽  
Mucous Cell ◽  
Volume Density ◽  
Cellular Level ◽  
Control Fish ◽  
Mortality Data ◽  
Mucous Cells ◽  
Exposed Fish

Gill samples from juvenile brook trout (Salvelinus fontinalis) acclimated to low-level aluminum at pH 5.2 showed severe damage by day 4, with necrosis and fusion of secondary lamellae and hyperplasia and hypertrophy of mucous cells. Over the following 20 d, there was a continual process of repair with proliferation and hypertrophy of mucous cells. Qualitative analysis of gill samples plus physiology and mortality data collected in a companion study indicated progressive development (by day 10 onward) of increasing acclimation to Al. Quantitative analysis of gill samples on day 13 showed that mucous cell volume density had tripled and mucous cell area had doubled in Al-exposed fish compared with control fish. A lamellar fusion index showed evidence of fusion in Al-exposed fish by day 4 with recovery to nearly control levels by day 13. Physiological disturbances appear to be directly related to the histological changes observed in the gill epithelium. At the cellular level, changes in either mucous cell production and secretion or changes in mucus chemistry contribute, in part, to acclimation to Al.

Effects of Long-Term Preexposure to Sublethal Concentrations of Acid and Aluminum on the Ventilatory Response to Aluminum Challenge in Brook Trout (Salvelinus fontinalis)

1991 ◽  
Vol 48 (10) ◽  
pp. 1989-1995 ◽  
Author(s):  
R. L. Walker ◽  
C. M. Wood ◽  
H. L. Bergman
Keyword(s):  
Stroke Volume ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Ventilatory Response ◽  
Lethal Dose ◽  
Control Fish ◽  
Twofold Increase ◽  
Arterial Ph ◽  
Sublethal Concentrations

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.

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