Effects of Oxygen in Relation to Temperature on the Development of Embryos of Brook Trout and Rainbow Trout

1966 ◽  
Vol 23 (8) ◽  
pp. 1121-1134 ◽  
Author(s):  
E. T. Garside
Keyword(s):  
Rainbow Trout ◽  
Dissolved Oxygen ◽  
Late Stage ◽  
Brook Trout ◽  
Control Level ◽  
Salmo Gairdneri ◽  
Pertinent Literature ◽  
Stage Of Development ◽  
The Times ◽  
Increasing Temperature

Embryos of the brook trout (Salvelinus fontinalis Mitchill) were incubated in reduced levels of dissolved oxygen of approximately 2.5 ppm, 3.5 ppm, 4.5 ppm, and a control level near air-saturation (10 ppm) at each four temperatures, 2.5, 5.0, 7.5, and 10.0 C, from fertilization to a late stage of development. Embryos of the rainbow trout (Salmo gairdneri Richardson) were incubated in a similar experiment at levels of oxygen approximating 2.5 and 3.5 ppm and a level near air-saturation at each of the four temperatures, to a similar, late stage of development. A third small experiment was conducted in which embryos of rainbow trout were incubated at 12.5, 15.0, and 17.5 C, at a level of dissolved oxygen near air-saturation. In all instances for both species the velocity of embryonic development, measured by the times required to attain a series of selected embryonic stages, was accelerated by increasing temperature. The velocity of development was increasingly retarded by progressively lower levels of dissolved oxygen. The times required to affect hatching and the lengths of the periods of hatching were similarly influenced by temperature and by the level of dissolved oxygen. These findings are discussed in the light of pertinent literature.

Food Specialization By Individual Trout

1972 ◽  
Vol 29 (11) ◽  
pp. 1615-1624 ◽  
Author(s):  
James E. Bryan ◽  
P. A. Larkin
Keyword(s):  
Rainbow Trout ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Stomach Contents ◽  
Cutthroat Trout ◽  
Salmo Gairdneri ◽  
Potential Prey ◽  
Repeated Observation ◽  
Size Growth ◽  
Salmo Clarki

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.

Aeromonas salmonicida: Relationship between Extracellular Growth Products and Isolate Virulence

1981 ◽  
Vol 38 (11) ◽  
pp. 1322-1326 ◽  
Author(s):  
Rocco C. Cipriano ◽  
Billy R. Griffin ◽  
Burton C. Lidgerding
Keyword(s):  
Rainbow Trout ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Aeromonas Salmonicida ◽  
Salmo Gairdneri ◽  
Lesion Development ◽  
Culture Supernatants ◽  
Crude Material

Extracellular growth products, extracted from culture supernatants of Aeromonas salmonicida by precipitation with ammonium sulfate and ethanol, were resolved into four fractions by ion-exchange chromatography. Although one of these (fraction II) possessed leukocytolytic activity, virulence of the pathogen was not associated with leukocytotoxicity. A positive correlation was established, however, between virulence and the toxicity of extracted material to cultured rainbow trout gonad (RTG-2) cells. The crude material and fractions II and III from virulent isolates were more toxic to RTG-2 cells than were similar preparations from avirulent isolates. Preparations from virulent isolates caused hemorrhaging, lesion development, and mortality when injected intramuscularly into brook trout (Salvelinus fontinalis) and Atlantic salmon (Salmo solar). Rainbow trout (Salmo gairdneri) were more resistant and lesions could be produced only with fraction II. Fraction II also possessed proteolytic activity.Key words: Aeromonas salmonicida, furunculosis, pathogenicity, salmonids, extracellular products, cytotoxicity, leukocytolysis, proteolysis, fishes

Bacterial Kidney Disease in Feral Populations of Brook Trout (Salvelinus fontinalis), Brown Trout (Salmo trutta), and Rainbow Trout (Salmo gairdneri)

1979 ◽  
Vol 36 (11) ◽  
pp. 1370-1376 ◽  
Author(s):  
Douglas L. Mitchum ◽  
Loris E. Sherman ◽  
George T. Baxter
Keyword(s):  
Rainbow Trout ◽  
Kidney Disease ◽  
Brown Trout ◽  
Brook Trout ◽  
Salmo Trutta ◽  
Salmo Gairdneri ◽  
Age Classes ◽  
Bacterial Kidney Disease ◽  
Live Fish ◽  
Brown Trout Salmo Trutta

Incidence and effects of bacterial kidney disease (BKD) were determined in wild, naturally reproducing populations of brook trout (Salvelinus fontinalis), brown trout (Salmo trutta), and rainbow trout (Salmo gairdneri) in a small lake and stream system in southeastern Wyoming, USA where BKD epizootics have been observed since 1972. During 1976, dead fish were collected at three upstream stations, and 60 live fish were collected from each of 11 stations. All fish were necropsied, and virological, bacteriological, and parasitological examinations were conducted by standard methods. An indirect fluorescent antibody technique was used to detect the BKD organism in cultures and kidney tissue smears. Bacterial kidney disease was diagnosed in 100% of the dead brook trout collected. Incidence among live fish ranged from 83% at an upstream station to only 3% at the most downstream location, and was highest in brook trout and lowest in rainbow trout. Two longnose suckers (Catostomus catostomus), the only non-salmonids collected, were found negative for BKD. Clinical signs of infection and the most severe infections were found only in brook trout. Five age-classes of feral brook trout were involved in the epizootics. Since other known pathogens were essentially absent, it is believed that all deaths were due to BKD. Relationships between species susceptibility to BKD, age-classes, water chemistry and water temperatures, and certain ecological conditions are discussed. Key words: bacterial kidney disease, feral trout, epizootics, brook trout, brown trout, rainbow trout

Susceptibility of Trouts of Different Species and Origins to Various Isolates of Infectious Pancreatic Necrosis Virus

1982 ◽  
Vol 39 (12) ◽  
pp. 1580-1584 ◽  
Author(s):  
A. Silim ◽  
M. A. S. Y. Elazhary ◽  
A. Lagacé
Keyword(s):  
Rainbow Trout ◽  
Brook Trout ◽  
Pancreatic Necrosis ◽  
Lake Trout ◽  
Infectious Pancreatic Necrosis Virus ◽  
Infected Fish ◽  
Salmo Gairdneri ◽  
Necrosis Virus ◽  
Infectious Pancreatic Necrosis ◽  
Pancreatic Necrosis Virus

We investigated the susceptibility of trouts of different species and origins to infectious pancreatic necrosis virus (IPNV) and the pathogenicity of three strains of IPNV for brook trout (Salvelinus fontinalis) of various origins and lake trout (Salvelinus namaycush) of a single origin. Fish were inoculated by immersion in water containing 105 PFU of virus/mL for 6 h. Susceptibility to IPNV infection was assessed by counting dead fish over a period of 21 d after infection and on histological lesions in the pancreas, kidney, and intestine of the infected fish. Different species of trouts had different susceptibility to IPNV strain 3865. Brook trout had the highest mortality followed by rainbow trout (Salmo gairdneri), whereas the least mortality occurred in lake trout. Brook trout from Crowford, Nebraska, were more than twice as susceptible as the same species from Baldwin Mills, Quebec. Rainbow trout also varied in susceptibility as a result of origin. Virus isolate 3B, originally isolated from chain pickerel (Esox niger), was less virulent than isolates 4495 or 3865 (both from trout). Hatcheries that use water from sources containing pickerel may increase their chances of IPN infection.Key words: trout species, infectious pancreatic necrosis virus, resistance

Models of Ammonia Excretion for Brook Trout (Salvelinus fontinalis) and Rainbow Trout (Salmo gairdneri)

1980 ◽  
Vol 37 (9) ◽  
pp. 1421-1425 ◽  
Author(s):  
Larry J. Paulson
Keyword(s):  
Body Weight ◽  
Rainbow Trout ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Ammonia Excretion ◽  
Salmo Gairdneri ◽  
Feeding Rates ◽  
Data Set ◽  
Nitrogen Consumption ◽  
Good Agreement

Ammonia excretion by brook trout (Salvelinus fontinalis) and rainbow trout (Salmo gairdneri) was measured in relation to nitrogen consumption, body weight (15–154 g for rainbow trout and 50–360 g for brook trout), and temperature (11.2–21.0 °C) under laboratory conditions. Four natural diets, collected from Castle Lake, California, and a commercial pellet diet were fed to the trout in gelatin capsules at feeding rates from 2.5 to 5% body weight∙d−1. Nitrogen consumption was the most important factor influencing ammonia excretion, followed by body weight and temperature. Testing the models with an independent data set revealed good agreement between measured and predicted rates of excretion. The models seem to estimate adequately ammonia excretion by trout in both natural and artificial aquatic systems.Key words: models, ammonia excretion, nitrogen consumption, body weight, temperature, multiple regression, rainbow trout, brook trout

Changes in the visual pigments of trout

1973 ◽  
Vol 51 (9) ◽  
pp. 901-914 ◽  
Author(s):  
Donald M. Allen ◽  
William N. McFarland ◽  
Frederick W. Munz ◽  
Hugh A. Poston
Keyword(s):  
Rainbow Trout ◽  
Brown Trout ◽  
Visual Pigment ◽  
Brook Trout ◽  
Forest Canopy ◽  
Environmental Control ◽  
Cutthroat Trout ◽  
Visual Pigments ◽  
Salmo Gairdneri ◽  
Canopy Access

The proportions of two visual pigments (rhodopsin and porphyropsin) were examined in four species of trout under experimental and natural conditions. Brook trout (Salvelinus fontinalis), rainbow trout (Salmo gairdneri), and brown trout (Salmo trutta) have different relative proportions of visual pigments in their retinae. The visual pigment balance in wild cutthroat trout (Salmo clarki) is related to forest canopy (access to light) and season. The brown trout have a more red-sensitive and less labile pair of visual pigments than brook or rainbow trout, which respond to photic conditions by increasing the proportion of porphyropsin (in light) and increasing rhodopsin (in darkness). The brown trout have a high percentage of porphyropsin, regardless of experimental conditions. This result does not reflect an inability to form rhodopsin but rather may relate to a consistently high proportion of 3-dehydroretinol in the pigment epithelium. The possible advantages and mechanisms of environmental control of trout visual pigment absorbance, as currently understood, are discussed.

Myxosoma cerebralis: Inactivation of Spores by Hot Smoking of Infected Trout

1982 ◽  
Vol 39 (6) ◽  
pp. 926-928 ◽  
Author(s):  
Ken Wolf ◽  
Maria E. Markiw
Keyword(s):  
Rainbow Trout ◽  
Aquatic Environment ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Soil Samples ◽  
Healthy Tissue ◽  
Salmo Gairdneri ◽  
Heat Inactivation ◽  
Whirling Disease

We processed 2-yr-old rainbow trout (Salmo gairdneri) and brook trout (Salvelinus fontinalis) with clinical whirling disease, which is caused by Myxosoma cerebralis, in one of the following ways: iced, iced and brined, or iced, brined, and hot smoked at 66 °C for 40 min. Skeletal elements of each group were added to tanks containing soil samples from an aquatic environment free of M. cerebralis and aged for 4 mo at 12.5 °C. Following this we assayed for infectivity by holding susceptible rainbow trout fry for 3 mo in the tanks of aquatic soil and skeletal elements. The fry were then examined for M. cerebralis spores. Spores were found in the fry from tanks that had received iced and iced and brined samples, but not in fry from the tanks containing hot smoked tissue, healthy tissue, or no tissue — the last two being negative controls.Key words: whirling disease, Myxosoma cerebralis, heat inactivation, hot smoking

Recovery of Planted Brook Trout, Splake, and Rainbow Trout from Selected Ontario Lakes

1972 ◽  
Vol 29 (2) ◽  
pp. 129-142 ◽  
Author(s):  
J. M. Fraser
Keyword(s):  
Rainbow Trout ◽  
Brook Trout ◽  
Fish Community ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Low Fertility ◽  
Salmo Gairdneri ◽  
White Sucker ◽  
The Mean ◽  
Brook Stickleback

Recoveries of hatchery-reared brook trout (Salvelinus fontinalis), splake (Salvelinus namaycush × S. fontinalis), and rainbow trout (Salmo gairdneri), planted in lakes having different resident fishes, were highest (9–30%) in a lake in which minnows and the brook stickleback were the only other fishes. Recoveries, by angling and gillnetting, were considerably lower (2–15%) in two lakes containing the white sucker and minnows, and still lower (0.5–5%,) in two lakes containing spiny-rayed species as well. Recoveries were lowest (< 0.5%) in a lake having a complex fish community that included native brook and lake trout. Planted splake and rainbow trout generally yielded higher returns, in weight, than brook trout in comparable situations.The low survival of planted fish was apparently due to the low fertility of the waters and to competition with, or predation by, resident fish species. Predation by fish-eating birds and mammals may also have had an effect.The weight of the catch of salmonids exceeded the weight planted in only one lake. Here, the mean yield of planted salmonids was 8.4 kg/ha per year in comparison with 2.6 to < 0.5 kg/ha per year in the five other study lakes.

Increased Toxicity of Ammonia to Rainbow Trout (Salmo gairdneri) Resulting from Reduced Concentrations of Dissolved Oxygen

1981 ◽  
Vol 38 (8) ◽  
pp. 983-988 ◽  
Author(s):  
Robert V. Thurston ◽  
Glenn R. Phillips ◽  
Rosemarie C. Russo ◽  
Susan M. Hinkins
Keyword(s):  
Rainbow Trout ◽  
Dissolved Oxygen ◽  
Ammonia Toxicity ◽  
Control Fish ◽  
Toxicity Tests ◽  
Salmo Gairdneri ◽  
Median Lethal Concentration ◽  
Positive Linear Correlation ◽  
Acute Toxicity Tests ◽  
Flow Through

The median lethal concentration (LC50) of aqueous ammonia at reduced dissolved oxygen (D.O.) concentrations was tested in acute toxicity tests with rainbow trout (Salmo gairdneri) fingerlings. Fifteen 96-h flow-through tests were conducted over the D.O. range 2.6–8.6 mg/L, the former concentration being the lowest at which control fish survived. There was a positive linear correlation between LC50 (milligrams per litre un-ionized ammonia) and D.O. over the entire D.O. range tested; ammonia toxicity increased as D.O. decreased. Ammonia LC50 values were also computed for 12, 24, 48, and 72 h; the correlation with D.O. was greater the shorter the time period.Key words: ammonia toxicity, dissolved oxygen, rainbow trout, Salmo gairdneri

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