Effects of temperature and photoperiod on the duration of hatching, swimming, and copepodid survival of the parasitic copepod Salmincola edwardsii

1993 ◽  
Vol 71 (5) ◽  
pp. 972-976 ◽  
Author(s):  
David C. Conley ◽  
Mark A. Curtis
Keyword(s):  
Water Temperature ◽  
Brook Trout ◽  
Laboratory Experiments ◽  
Hatching Success ◽  
Salvelinus Fontinalis ◽  
Parasitic Copepod ◽  
Swimming Activity ◽  
The Other ◽  
Egg Hatching ◽  
Effects Of Temperature

We conducted laboratory experiments to test whether various temperature and photoperiod regimes had any effect on the duration of egg hatching, swimming activity, and copepodid survival in the parasitic copepod Salmincola edwardsii, commonly found on brook trout (Salvelinus fontinalis). Pairs of egg sacs were removed from adult female copepods; one of each pair was exposed to a different photoperiod than the other, at the same temperature. Experiments were conducted at 8, 12, 16, and 20 °C. Temperature had a significant effect on the duration of copepodid swimming activity and survival, and the onset of egg sac hatching was directly related to increasing water temperature. However, hatching duration and hatching success were not affected by temperature over the range tested. Photoperiod had no effect on hatching duration, hatching success, swimming activity, or copepodid survival. Our findings indicate that S. edwardsii copepodids can swim and survive for more than 2 weeks; much longer than the 2 days customarily reported in the literature. This must be accounted for in the development of strategies to control transmission.

Effects of temperature fluctuations and photoperiod on hatching in the parasitic copepod Salmincola edwardsii

1990 ◽  
Vol 68 (6) ◽  
pp. 1330-1332 ◽  
Author(s):  
Robert Poulin ◽  
David C. Conley ◽  
Mark A. Curtis
Keyword(s):  
Brook Trout ◽  
Laboratory Experiments ◽  
Salvelinus Fontinalis ◽  
Temperature Fluctuations ◽  
Parasitic Copepod ◽  
The Other ◽  
Hatching Rate ◽  
Experimental Conditions ◽  
Effects Of Temperature ◽  
Daily Changes

In laboratory experiments, we studied the effects of the day–night cycle (photoperiod and temperature fluctuations) on the initiation of hatching and hatching rate in egg sacs of the copepod Salmincola edwardsii, ectoparasitic on brook trout (Salvelinus fontinalis). Pairs of egg sacs were removed from adult female copepods; for each pair, one sac was placed under experimental conditions and the other one was kept under constant conditions, providing an ideal control. Photoperiod had no significant effect on the initiation of hatching or hatching rate. The observed effects of temperature fluctuations were associated with water temperature itself, and appeared independent of whether it was fluctuating or constant. We conclude that hatching in S. edwardsii is not rhythmical but spontaneous, showing no relationship with daily changes in host vulnerability.

Larval development of the parasitic copepod Salmincola edwardsii on brook trout (Salvelinus fontinalis)

1994 ◽  
Vol 72 (1) ◽  
pp. 154-159 ◽  
Author(s):  
David C. Conley ◽  
Mark A. Curtis
Keyword(s):  
Larval Development ◽  
Brook Trout ◽  
Laboratory Experiments ◽  
Salvelinus Fontinalis ◽  
Infection Intensity ◽  
Parasitic Copepod ◽  
Developmental Time ◽  
Adult Males ◽  
Pectoral Fins ◽  
Adult Females

We conducted laboratory experiments to determine the developmental time from larva to adult of the parasitic copepod Salmincola edwardsii on brook trout (Salvelinus fontinalis) at 13 °C. Healthy fingerlings were exposed to large doses of recently hatched copepodids for 12 h. Three infected fingerlings were sacrificed at 12-h intervals until day 6 and then at 24-h intervals until day 20 postexposure. The gills, opercula, and pectoral fins were the major sites of attachment. Adult males were detected as early as day 3 and as late as day 8 postexposure, with the greatest number occurring about day 5. Adult males may live for up to 3 days at 13 °C. Adult females were detected as early as day 11 postexposure but not consistently until day 13, indicating that permanent bulla attachment took place between 11 and 16 days postexposure. Infection intensity declined rapidly until day 9 postexposure then less quickly for the rest of the experiment.

Some Factors Regulating Piscivory of Brook Trout, Salvelinus fontinalis, in Lakes of the Laurentian Shield

1991 ◽  
Vol 48 (9) ◽  
pp. 1735-1743 ◽  
Author(s):  
Pierre East ◽  
Pierre Magnan
Keyword(s):  
Brook Trout ◽  
Laboratory Experiments ◽  
Salvelinus Fontinalis ◽  
The Other ◽  
Prey Fish ◽  
Significant Preference ◽  
Prey Refuge ◽  
Semotilus Atromaculatus ◽  
Foraging Pattern ◽  
Creek Chub

A survey of 13 lakes containing brook trout, Salvelinus fontinalis, and northern redbelly dace, Phoxinus eos, five lakes containing trout and creek chub, Semotilus atromaculatus, and six lakes containing trout, dace, and chub indicated that prey-fish could represent up to 30% of trout diet by weight. We observed that trout preyed almost exclusively on dace, predation increased with trout size, predation on dace was significantly higher in the Salvelinus-Phoxinus-Semotilus association than in the Salvelinus-Phoxinus association even though trout were significantly smaller in the former than in the latter association, and predation in the Salvelinus-Phoxinus-Semotilus association was higher in two lakes and nearly always absent in the other four. Laboratory experiments indicated that small trout (150–250 mm total length (TL)) preferred small prey-fish (40–60 mm TL), large trout (250–380 mm TL) showed no significant preference with regard to the size of prey-fish (up to 170 mm TL), trout of both size classes preferred dace when dace and chub were present, presence of refuge (Cassandra calyculata) for prey-fish significantly reduced the number of attacks and captures upon dace, and large trout switched from an active to a sit-and-wait foraging pattern when a prey refuge was present.

Growth and Resistance to Stress in Brook Trout Fed Sublethal Levels of DDT

1968 ◽  
Vol 25 (11) ◽  
pp. 2443-2451 ◽  
Author(s):  
Kenneth J. Macek
Keyword(s):  
Weight Gain ◽  
Water Temperature ◽  
Brook Trout ◽  
Feeding Rate ◽  
Salvelinus Fontinalis ◽  
Physiological Stress ◽  
Environmental Stresses ◽  
Exposed Fish ◽  
Cumulative Mortality ◽  
Resistance To Stress

When underyearling brook trout (Salvelinus fontinalis) were fed DDT at a rate of 2.0 mg/kg per week for 31 weeks, they exhibited greater weight gain (43.2 ± 0.8 g) during the period than did untreated fish (36.6 ± 1.1 g). When underyearling fish were fed DDT at different rates for 26 weeks and then starved or fed at a rate equivalent to 10% of the usual feeding rate, the cumulative mortality during this period was 96.2% among fish exposed to 3.0 mg/kg per week, 88.6% among fish exposed to 2.0 mg/kg per week, and 1.2% among untreated fish. Differences in the length of survival of DDT-exposed fish occurred due to dosage, sex, and type of starvation. The evidence suggests that the mortality of DDT-exposed fish was due to the interaction of DDT residues with a combination of environmental stresses, namely starvation, decreasing water temperature, and possibly the physiological stress associated with the spawning season.

Influence of body weight, swimming characteristics, and water temperature on the cost of swimming in brook trout (Salvelinus fontinalis)

2000 ◽  
Vol 57 (7) ◽  
pp. 1482-1488 ◽  
Author(s):  
Ming Tang ◽  
Daniel Boisclair ◽  
Chantal Ménard ◽  
John A Downing
Keyword(s):  
Experimental Data ◽  
Water Temperature ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Significant Proportion ◽  
Average Difference ◽  
Fish Swimming ◽  
Experimental Conditions ◽  
Fish Weight ◽  
The Cost

We performed respirometry experiments to estimate the spontaneous swimming costs of brook trout (Salvelinus fontinalis) for 24 combinations of fish weight (3.5, 17, and 32 g), water temperature (4, 12, and 18°C), and respirometer size (27, 54, and 108 L). Fish swimming characteristics were estimated for each experiment using videocamera recordings and image analysis. Under our experimental conditions, average swimming characteristics of fish, such as swimming speed and turning and acceleration rates, varied from 2.5- to 29-fold. Our data, alone or combined with similar published results on brook trout weighing 1 g, indicated that fish weight was the only variable that could explain a statistically significant proportion of the variations of spontaneous swimming costs for that species (r2 = 0.91). Our work confirms, with a wider range of experimental data, that spontaneous swimming costs of fish are 3- to 22-fold (8-fold average difference) more energy demanding than predicted by forced swimming models developed using fish swimming at constant speeds and directions in flumes.

Responses of the fish ectoparasite Salmincola edwardsii (Copepoda) to stimulation, and their implication for host-finding

Parasitology ◽  
1990 ◽  
Vol 100 (3) ◽  
pp. 417-421 ◽  
Author(s):  
R. Poulin ◽  
M. A. Curtis ◽  
M. E. Rau
Keyword(s):  
Shock Waves ◽  
Mechanical Stimulation ◽  
Strong Evidence ◽  
Brook Trout ◽  
Laboratory Experiments ◽  
Salvelinus Fontinalis ◽  
Selective Pressure ◽  
Host Finding ◽  
And Shock Waves ◽  
Energy Stores

SUMMARYThe short-lived infective copepodid stages of the copepod Salmincola edwardsii, ectoparasitic on brook trout, Salvelinus fontinalis, are under strong selective pressure to evolve efficient host-finding mechanisms. In laboratory experiments, we quantified the effects of visual and mechanical stimulation on the activity of the copepodids. We found that shadows passing above the copepodids and shock waves passing through the water generated marked increases in the rate and length of upward swimming bursts, which resulted in more time spent suspended in the water column and greater distances travelled. However, we found no strong evidence for a relationship between the magnitude of the copepodids' response and the intensity of stimulation. Although these responses are not host-specific, they allow the parasites to conserve their limited energy stores by increasing their host-finding activity only when potential hosts are nearby.

Effects of Temperature on Growth and Survival of Young Brook Trout, Salvelinus fontinalis

1972 ◽  
Vol 29 (8) ◽  
pp. 1107-1112 ◽  
Author(s):  
J. Howard McCormick ◽  
Kenneth E. F. Hokanson ◽  
Bernard R. Jones
Keyword(s):  
Thermal Tolerance ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Mortality Rates ◽  
Temperature Tolerance ◽  
Tolerance Limits ◽  
Growth And Survival ◽  
Effects Of Temperature ◽  
Rates Of Growth ◽  
Upper Thermal Tolerance

Instantaneous rates of growth, mortality, and net biomass gain were determined for alevin through juvenile brook trout reared for 8 weeks at six constant temperatures: 7.1, 9.8, 12.4, 15.4, 17.9, and 19.5 C. Growth rates were maximum between 12.4 and 15.4 C. Mortality rates increased between 15.4 and 17.9 C and were maximum between 17.9 and 19.5 C. The net rates of biomass gain were maximum between 12.4 and 15.4 C.Median upper thermal tolerance limits (TL50 values) were determined for newly hatched and swim-up alevins. Tolerance did not increase in newly hatched alevins with acclimation to temperatures from 2.5 to 12 C. The upper 7-day TL50 for newly hatched alevins acclimated over this range of temperatures was 20.1 C. The swim-up alevins showed both an increase in temperature tolerance with acclimation temperatures between 7.5 and 12 C and an increase in tolerance over that of the newly hatched alevins at comparable acclimation temperatures. The ultimate 7-day TL50 of swim-up alevins was 24.5 C. Swim-up alevins exceed newly hatched alevins in thermal tolerance by 2.0–4.5 C, depending on the temperature of acclimation. The TL50 of newly hatched alevins of comparable acclimation (12 C) is reduced by about 2 C when the exposure time is increased from 1 to 7 days.

Relationship between respiration rate of juvenile brook trout (Salvelinus fontinalis), water temperature, and swimming characteristics

1995 ◽  
Vol 52 (10) ◽  
pp. 2138-2145 ◽  
Author(s):  
Ming Tang ◽  
Daniel Boisclair
Keyword(s):  
Water Temperature ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Oxygen Demand ◽  
Oxygen Depletion ◽  
Biological Oxygen Demand ◽  
Average Speed ◽  
Video Cameras ◽  
Cost Variation ◽  
The Cost

We estimated the cost of spontaneous swimming and the swimming characteristics of juvenile brook trout for 21 combinations of water temperature (3.5, 6, 9, 12, 15, 18, and 20.7 °C) and respirometer volume (27, 54, and 108 L). Spontaneous swimming costs were estimated as the oxygen depletion in the respirometers corrected for biological oxygen demand of the water and standard metabolism of the fish. Spontaneous swimming costs varied 9-fold among our experiments. Swimming characteristics, such as the average and the variance of speed, acceleration, and turning rates, were determined using a pair of video cameras. Swimming characteristics varied 2- to 10-fold among experiments. Speed and turning rate tended to increase with water temperature up to 18 °C and decreased at 20.7 °C. Water temperature (r2 = 0.44) was the only variable that could explain a significant portion of the variations of spontaneous swimming costs between 3.7 and 20.7 °C. Variance of speed (partial R2 = 0.32) and the average turning rate (partial R2 = 0.34) explained 53% of the variation between 3.7 and 18 °C. Average speed never explained more than 35% of spontaneous swimming cost variation.

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